I. What is the function of a capacitor?

Q: Huh? Can't move... why? I clearly connected the wires
A: What's wrong?
Q: I have already connected the wires, but the motor still won't move.
A: Let me see... it turns out so, no wonder it doesn't move. Because you didn't connect it to the capacitor. Have you carefully reviewed the wiring diagram?
Q: No... It was supposed to be connected to a capacitor. But what is a capacitor?
A: It's something connected to the motor! All single-phase power motors must be connected to capacitors.
Q: What are the functions of so-called capacitors?
A: Capacitors have two main functions.
(1) Control the direction of motor operation (convert single-phase power supply to two-phase)
(2) Drive the motor to generate torque (starting torque, rated torque)
And the capacitors matched with different motors are also different, so they must not be randomly matched.
Q: What would happen if inappropriate capacitors were used?
A: If a capacitor with excessive capacity is used, although it can also generate torque, the motor will generate abnormal heat and vibration. On the contrary, if capacitors with insufficient capacity are used, the torque will decrease, so it is not recommended to use capacitors with incompatible capacity.
Q: Hmm... but where is the capacity recorded?
A: It is recorded on the nameplate of the motor. Isn't it written here as 5 μ F! This represents the capacity of the capacitor.
Q: I see. So, what is the difference between the capacitors used in the motors stored in the warehouse that were circular and those used in the motors that were square?
A: Basically, as long as the capacity and voltage are the same, both can be used. But as the capacitor is made in different ways, its shape will also change accordingly. It is only possible that there may be differences in wiring methods, so attention should be paid when replacing capacitors.
Q: Do capacitors also need to be replaced?
A: The motor will eventually end its lifespan after long-term use. When purchasing a new single-phase motor, an electrical container will be included, and it would be better to replace it together with the motor at that time!
I learned a lot today, and I still need to learn more from you in the future!

II.Can Taiwanese voltage specification products be used in Japan?

Q: Can a 25W speed regulating motor with a voltage specification of 220V from Taiwan also be used in Japan?
A: Do you know what voltage is used in Japan?
Q: Huh? Isn't he the same as us?
A: Japan uses single-phase 200V 50/60Hz!
Q: Isn't that okay? The specifications of speed regulating motor products from Japan's Dongfang Motor can be used within the range of single-phase 200 ± 10%, right?
A: Although this is the voltage variation range allowed by the motor, it does not actually guarantee that it is the optimal usage range! If the voltage fluctuates instantaneously within the allowable range, the motor will not produce abnormal phenomena. However, if it is continuously used at a voltage of 200V, it will cause insufficient output of the motor (not reaching the rated output), resulting in a decrease in torque and even the inability to drive the load. On the contrary, if a 200V motor is used in a 220V environment, although the output torque of the motor can be increased, the temperature of the motor will be higher than in normal use, and not only that, it may also shorten the life of the motor! Can't we recommend the selected motor to the customer for use this time?
Q: Hmm, yes. What would be better to introduce?
A: By the way, don't we have MSS and W series products that have both passed the world standard certification and meet Japanese standards? There is also an introduction on the Chinese comprehensive catalog! MSS425-402WJ is the most suitable for this case. (Voltage specification 200V)
Q: Yes, the voltage specification is 200/220/230V and it can be used. But wouldn't it be a problem to suggest customers use substitutes? For example, there may be differences in external dimensions and so on
A: Don't worry! Because the motor size is consistent, customers can directly connect it with the selected reducer for use. Moreover, in addition to the protective cover of the attached electrical container, there are also relay cables for customers to use with peace of mind.
Q: I understand now, so I dare to boldly introduce myself to clients!
A: MSS and W series also have products corresponding to various voltages, which can be used safely and securely according to customer needs. And besides MSS, W series, and world standard K series, our company also has a considerable number of products corresponding to various specifications!
Q: That's right, that's right. Both stepper motors and fans do have products corresponding to overseas specifications!
A: In order to ensure that customers around the world can use Dongfang Motor's products with peace of mind, we have a wide range of safety specifications corresponding to our products, and we do not have any sales bases around the world!
Q: I understand, please contact the customer immediately!

III.Can reversible motors only be used for 30 minutes?

Q: It's really hot today, but it's so nice to come and play in the haunted house with you!
A: You startled me, be careful not to flash it to your waist!
Q: Ah! I'm scared to death. Hey, take a closer look at this ghost, it's using a reversible motor to run out and scare people!
A: Oh! You are quite clear about it.
Q: Ah! The motor feels very hot to the touch! Is it due to prolonged physical activity?
A: Do you know what a reversible motor is? Tell me.
Q: Of course I know! The so-called reversible motor is a motor that can instantly switch between forward and reverse rotation, suitable for use in situations where repeated operation and stopping are required.
A: Yes! Good learning.
Q: By the way! Isn't it written in the catalog that reversible motors are rated for 30 minutes? Does it mean it can only take 30 minutes?
A: Well, if a reversible motor is used for continuous operation in the same direction as an induction motor, it can only be used for 30 minutes!
Q: Why is that?
A: This is related to the characteristics of reversible motors. The so-called reversible motor is designed to achieve the function of instantaneous forward and reverse rotation. Therefore, compared with induction motor, the current passing through during operation is more and the temperature is more likely to rise. That's why it is recommended that customers use reversible motor for continuous operation for 30 minutes!
Q: So that's how it is.
A: However, if the temperature can be avoided from rising too quickly, the usage time can be further extended! Generally speaking, if the temperature of the motor casing remains below 90 degrees, it can operate for more than 30 minutes. Although it is best to use at temperatures below 90 degrees, the lifespan of the motor still depends on the temperature. Of course, it would be best if it could operate at low temperatures.
Q: Is there any way to avoid motor temperature rise?
A: The temperature of the motor may vary due to various factors such as load, operating cycle, motor installation method, and surrounding environment. Therefore, methods such as directly cooling the motor, installing heat dissipation plates, or reducing the motor's operating time to allow it to cool naturally can all prevent the motor from rising too quickly and increase its service life.
Q: I see, I understand. Although reversible motors are rated for 30 minutes, as long as you pay attention to the temperature changes in the motor casing, they can still operate continuously for more than 30 minutes. I learned so much today!
A: Be careful!
Q: Hmm? Wow

IV.Does noise also have certain rules?

Q: The road ahead is under renovation and has been noisy all day, making it impossible to work.
A: Yes. This is called 'noise'.
Q: But if you close the window, the office will become very stuffy.
A: You might as well borrow the fan in the showroom to dissipate heat. (laughs)
Q: You bullied me again. By the way! The so-called noise, in the series of fans published in the comprehensive catalog, seems to mention the noise value.
A: Yes, fans have a wide range of uses. Not only factories, offices, and hospitals use fans, so noise levels are also considered when selecting them! Speaking of noise level, it refers to the value measured in the A-band within a distance of 1 meter from the side where the fan sucks in air.
Q: Huh~What is the frequency band?
A: Since the human ear can hear sounds with frequencies between 20Hz and 20kHz, the noise level is close to the range that humans can hear, which is the A-band.
Q: I don't even know! Does the noise from road construction belong to the A band?
A: Well, the noise level of a typical road construction project is about 110 decibels. By the way! The fan produced by Dongfang Motor is about 40 decibels, which is equivalent to the sound in a quiet park!
Q: Hmm~But the sound heard in different places is different in size!
A: Yes! Depending on the distance of the test, the noise level will also vary, so we will definitely clearly indicate the test distance in meters on our catalog!
Q: Really! This is indeed a value measured at a distance of 1 meter from the air intake side of the fan.
A: Different distances are measured, and the values obtained will also change. When comparing, it is important to first confirm how far the measured distance is!
Q: I think although a low decibel value means a low noise level, is it allowed to measure at a slightly farther distance?
A: So it's important to pay attention to the distance being measured. There are certain rules regarding the noise level and distance. For example, if the measurement distance is extended from 1 meter to 2 meters, the noise level will decrease by 6 decibels; Extending to 4 meters will reduce the noise level by 6 decibels, for a total reduction of 12 decibels. On the contrary, if the measurement distance is shortened from 1 meter to 50 centimeters, the noise level will increase by 6 decibels!
Q: Hmm~So as long as you know the noise level generated within a certain distance, you can calculate the noise level at different distances!
A: Yes.
Q: I understand now! Try to calculate now!
A: It seems like the sound of road repairs has stopped unconsciously while chatting with you.
Q: (Gollum Gollum~)
A: The sound of a stomach growl should be 30 decibels!
Q: It's already noon! Of course, my stomach should growl! What are you going to eat today?

V.The larger the reduction ratio, the greater the output torque?

Q: How heavy~How heavy~Ah!
A: Move it up quickly!
Q: This thing is really heavy. Isn't it enough to use a conveyor belt? By using a gearbox to increase torque, it is easy to transport goods, isn't it? By the way! Is it true that the larger the reduction ratio, the greater the output torque?
A: Yes.
Q: The allowable torque algorithm for installing the gearbox is... TG=TM × I × η
Allowable torque of the output shaft of the gearbox
TM motor torque
Reduction ratio of I gearbox
Communication efficiency
For example, the combination of the world standard K-series induction motor "4IK25GN-AWU" and the gearbox "4GN180K" is: TM: 205mN · m/η: 66%
So, when these numbers are inserted into the formula, it is:
TG=0.205×180×0.66=24.354 N⋅mTG​=0.205×180×0.66=24.354N⋅m
That is to say, the higher the reduction ratio of the gearbox, the higher its torque can be!
A: Yes, but torque cannot just be calculated by formulas! Actually, it depends on the maximum allowable torque of the gearbox, and there is still an upper limit to the load torque it can withstand!
Q: Is that so?
A: Because the reducer is composed of components such as gears and bearings, it is affected by material and size, and has mechanical strength limitations. Therefore, the allowable torque cannot exceed the limit of mechanical strength!
Q: Well, what would happen if it were used in situations where the maximum allowable torque is exceeded?
A: According to the design of the reducer, the mechanical strength is about 1.5 to 3 times the maximum allowable torque, so a brief overload will hardly cause damage, but it will shorten the service life due to frequency and time of use! So it is not recommended for customers to use it beyond the maximum allowable torque!
Q: So that's right, which means the maximum allowable torque for the combination of "4IK25GN-AWU" and "4GN180K" is 8.0N · m. Only when used within this range can the motor achieve its maximum efficiency.
A: That's right! What should I do if I need a larger torque?
Q: If considering the maximum allowable torque of the gearbox, I think using the high-strength and long-life V series ※ (6W~60W) is a good method. For example, for the same 25W model, if using the V series ※, the maximum allowable torque can reach 16N · m! If the selected torque is insufficient, there are also BH series 200W models available for selection. When installing the reducer, the maximum corresponding torque can reach 70N · m!
A: It's really rare that you put in a lot of effort! But you still missed one! The high-strength FR series ※ is adopted, and the maximum allowable torque of the 90W output power model can also reach 68N · m. It is used in combination with a brushless motor and can also be adjusted in speed!
Q: Yes, the FR series is also a good choice. Oh, speaking of which, aren't you going to use a conveyor belt to transport goods? I don't want to move quickly yet!

VI.What is the maximum distance that can be extended between the motor unit of the speed regulating motor and the speed regulator?

Q: I would like to make some changes to the speed control motor mechanism on the display machine in the motor display area. The current torque of the motor should not be a problem, but the cable between the motor and the governor needs to be extended. May I ask how many meters it can be extended to?
A: Hmm... it depends on the motor used and cannot be generalized. That display machine is using the AXU series, right! The maximum extension distance should be 10.5 meters.
Q: I only need to extend by 1 meter, that's definitely not a problem. But I want to know, what if the extension distance exceeds 10.5 meters?
A: The longer the extension distance, the higher the resistance of the wire will increase, causing a decrease in voltage. That is to say, the decrease in current through the motor causes a decrease in torque. In addition, the longer the extension distance, the more susceptible it is to noise interference. If the usage environment is poor, it may cause motor misoperation.
Q: I see. That means it's not good to extend the distance too long, right?
A: Yes. Additionally, when extending, pay attention to the AWG of the motor wires.
Q: AWG? What is this again?
A: AWG is the abbreviation for American Wiring Gage, which refers to the code for the composition of the wire core and the cross-sectional area of the conductor. It is generally called AWG No. The larger the number, the smaller the cross-sectional area of the wire and the thinner the wire.
Q: Oh, that's right. So what does this have to do with the extension distance of the wire?
A: The smaller the cross-sectional area of the wire, the greater the resistance, making it difficult for current to pass through, resulting in a decrease in torque. So, when extending, the same AWG number wire as recorded on the motor wire should be used or a thicker wire should be used. This is also a key point to pay attention to for other motors such as stepper motors.
Q: So there are still such precautions. So, next I have to prepare the wires. Hmm? Which type of wire is good to use?
A: There are various extension cables for speed regulating motors in the selection of accessories! If the cable with optional accessories is used, as the AWG is the same, there will be no problem as long as it is used in a normal environment and within the specified extension distance range. For the AXU series, the One Touch connector is used between the motor and the governor, which makes it even simpler.
Q: Ah! That's really the case! The AXU series has an extension cable with a length of 10m. Not only is the length sufficient, but the wiring is also simple, it's really great! By the way, if I use cables other than optional accessories, can they also be extended?
A: Products like AXU series cables with connectors at the front end cannot be extended if cables other than optional accessories are used. So we have prepared several lengths of cables to meet the needs of users. Also, for products like the SC series speed regulating motor with bare wire type wires, extension can be done even without using optional accessory cables. However, attention must be paid to the several points I just explained.
Q: It's noise and AWG, right!
A: Yes. Especially for signal lines such as speed control motor generator wires, the longer the extension distance, the more susceptible they are to noise interference. Therefore, it is recommended to control the extension distance within 10m. In addition, it would be better if not only the speed generator wires, but also all Mazda could adopt measures such as separating the power line from the motor power line or using twisted pair wires, shielded wires, etc. For example, when selecting various series of specialized cables for accessories, the signal line uses twisted pair and has been shielded, making it very convenient. It goes without saying that the extension cables of the AXU series have also undergone shielding treatment.
Q: I see! I finally understand. Okay, then I'll go and change the display machine right away. Thank you, goodbye!!

VII. Why is' inertia 'very important when choosing a motor?

Q: Although the wheels of this bicycle are so big, the pedals are so light. It runs so fast!
A: This is because the wheels of this bicycle are designed to be relatively thin according to racing specifications, reducing inertia, which is why it runs so fast!
Q: Is inertia proportional to weight?
A: That's right, but it's not just that!
Q: What else is there?
A: It is also directly proportional to the square of the radius!
Q: I see. When the umbrella is opened and rotated, it feels heavier compared to when it is retracted, and that's exactly why.
A: So, you should understand the impact of inertia when choosing a motor, right?
Q: Hmm? Will it affect the acceleration and deceleration torque that occurs during starting and deceleration?
A: Yes! The greater the inertia, the more proportional the acceleration and deceleration torque will be. What else do you remember?
Q: Is there anything else?
A: You still need to study hard! We also need to consider the allowable inertia and inertia ratio!
Q: Ah! I remember it. When selecting an AC motor, it is also important to note that the allowable inertia of the reducer must exceed the inertia of the equipment (i.e. the load inertia). If the inertia of the load exceeds the inertia of the gearbox, the gearbox will not be able to withstand it and may be damaged.
A: Do you remember last week when you were playing with an umbrella and the umbrella frame broke because you couldn't withstand the acceleration and deceleration torque of inertia? What would happen if it were a stepper motor?
Q: Remember that for a stepper motor, the inertia ratio between the rotor inertia and the load inertia can be calculated using the formula "inertia ratio=load inertia ÷ rotor inertia", and the motor must be selected based on the condition that the inertia ratio is less than 10 times (less than 30 times in α STEP)! But why do we need to consider inertia ratio?
A: This is because even if there is a certain margin of acceleration and deceleration torque, if the inertia ratio is too large, it will not be able to keep up with the acceleration command and cause stepping loss.
Q: Should servo motors and brushless speed regulating motors be selected based on the condition that the allowable inertia (i.e. applicable load inertia) must exceed the load inertia?
A: Yes! If the allowable inertia (i.e. applicable inertia) is exceeded, reliable control cannot be achieved, resulting in unstable motion, warning output, and motor stoppage.
Q: So, as long as a reducer is used to reduce speed, even with a small motor, it can still drive loads with high inertia, right?
A: Oh, you finally have an epiphany! As long as we consider according to the "allowable inertia (applicable load inertia) x reduction ratio ²", it means that we can drive a load equal to the square of the reduction ratio. If your bicycle only needs to slow down by half, it can withstand a load equivalent to the second power of the reduction ratio, which is 4 times the load. How about it? Can I hand over my luggage to you?
Q: In this way, won't my speed be reduced by half? I'm not so stupid yet!

VIII.Could you please tell me what the warning circuit for a fan is?

Q: I am checking if the display machine in the showroom is functioning properly. Oh, that's great! The cooling fan is also fine. But I would like to ask, because this is a display room and the fans are installed in prominent positions, it is also very convenient to check. But if installed in a completely invisible place or far away, it can be troublesome to check. Do you know any simple inspection methods?
A: This time you've hit the nail on the head. In fact, it is impossible for all devices to be set up in places where people are present. If this situation occurs, it is recommended to use a fan with a warning circuit.
Q: Warning circuit? Is it the kind of circuit that outputs a warning signal when the fan stops?
A: Not only that! There are many types of warning circuits for fans.
Q: Is that true?
A: Taking OM's fan products as an example, there are three types: speed drop detection type (non-contact/contact), stop detection type, and pulse detector output circuit type, and each product has different warning methods.
Q: There are so many gods! Then I won't be able to figure it out again! How should we use them separately?
A: It depends on under what circumstances you need the fan to output a warning signal.
Q: Oh, so it's still so complicated!
A: For example, if the fan speed decreases and causes equipment failure, it is recommended to use the "speed drop detection type". If it is a situation that can be handled after the fan stops, then the "stop detection type" is more suitable; The "pulse detector output circuit type" is suitable for monitoring the speed of the fan. Because the speed of the fan can be determined based on the number of output pulses, and any abnormalities in the fan can be detected in a timely manner. So, if it belongs to a situation where a slight decrease in speed will have a significant impact on the equipment, it is recommended to use this "pulse detector output circuit type".
Q: I see, there are actually so many types.
A: For example, the "speed reduction type" is detected and alerted by an external applied voltage and through the ON/OFF of an internal circuit. Taking the MRS series 250mm large high static pressure fan as an example, it is ON (open collector output: L level) when rotating normally, and OFF (open collector output: H level) when rotating back.
Q: Oh, do the other two circuits also use the same principle to detect warnings?
A: From the perspective that all three circuits are externally applied with voltage, although they are the same, there are slight differences due to differences in product and warning circuit types. Please double check your respective specifications.
Q: I understand now. As long as I use the warning output function, I don't have to check every day anymore. And if the fan blade gets stuck and stops, it can be immediately detected, so you can feel at ease now.

IX.May I ask what an overheat protector is?

Q: A customer just inquired about the sudden stop of a running motor. The world standard K series 25W induction motor used by the customer should not suddenly stop running.
A: That's right. Induction motors are marked with continuous ratings in the product catalog. Indicates that it can operate continuously for 24 hours. Usually, the motor does not stop when operating within the specified torque range.
Q: How about this. By the way, the customer said, "The device accidentally caught a foreign object and the motor shaft got stuck
A: That's probably the reason! Do you know that in the world standard K series, there is an overheat protection device for motors above 15W.
Q:?
A: In the product catalog, the product name is preceded by a symbol indicating that there is an overheat protection device installed in the Mazda. For the 6W motor (world standard K series), an impedance protection type overheat protection method is adopted.
Q: What is overheat protection?
A: This is an overheat protection device installed inside the motor. When the motor coil exceeds a certain temperature, it will automatically cut off the contact and stop the operation of the motor.
Q: Is that so? What is the function of the overheat protection device?
A: When the motor gets stuck due to overload or other reasons, the surrounding temperature rises sharply, or for some reason, the load increases, causing the temperature of the motor to rise sharply. If this situation is not addressed, the insulation performance inside the motor will deteriorate, resulting in a shortened motor life or the possibility of burning out the coil. An overheat protection device was installed to protect the motor in this situation. Motors that meet foreign safety standards must be equipped with overheat protection devices.
Q: So that's how it is. The protective function of preventing the motor from burning due to heat generation. Just now, it was mentioned that the overheat protection device will activate after exceeding a certain temperature. Under what temperature conditions will the overheat protection device activate?
A: In the specifications of the world standard K series, when the temperature of the coil inside the motor reaches 130 ℃± 5 ℃, the contact is automatically cut off, the temperature drops, and the contact is reconnected at 77 ℃± 15 ℃. However, depending on different models, some temperatures may vary. For detailed information, please confirm the specifications of the overheat protection devices for each motor.
Q: Okay.
A: Did you just mention that the customer had a problem with the motor shaft getting stuck! It is speculated that the motor may have abnormally heated up due to overload, thus exceeding a certain temperature.
Q: Indeed, it is very likely. However, if the motor is in a stopped state for a certain period of time, the temperature will naturally decrease. So after the contact is cut off and the motor stops, won't it automatically resume operation?
A: Yes. But some customers do not want automatic resumption of operation. For this situation, the electronic brake SB50 can be used in conjunction. The SB50 is equipped with an overheat protection switch detection function, which will not automatically resume operation, so it can be used with peace of mind. The overheat protection switch detection function of SB50 will output a warning signal when the motor's overheat protection is started but stopped, so this signal can also be used.
Q: Understood.
A: You can now make suggestions to this client, right!
Q: Okay, I'll tell the client right away!

X.What is' regenerated electricity '?

Q:!!
A: Oh, it's you! You look different, did you change your hairstyle or something?
Q: As expected, you can tell right away. In April, it will be my second year in the company, so I must work harder... Alright, let's not talk about hairstyles for now, I have to ask for advice again. A customer asked me, "Is there a motor that can control the speed when running in the up and down directions?" Which type of motor should I recommend?
A: What are your own thoughts?
Q: When the power is cut off, the output shaft of the electromagnetic brake motor with no excitation actuation will be mechanically restrained, right. So, does it mean that all speed control motors with electromagnetic brakes can be controlled for speed during up and down operation?
A: Not necessarily. Firstly, when selecting a motor, consider the direction of handling the customer's work first. Due to the different directions of handling work items, the motors used will be different! Let's take a look at the following two situations together.
Figure A: Drive direction upwards (roll up operation)
Figure B: Drive direction facing downwards (roll down operation/regeneration operation)
Q: Oh, that's right!
A: There are many motors that can control the speed when running on the roll, but there are not many motors that can control the speed when running off the roll. It is generally recommended to use DC brushless motors BX series/BHF series.
Q: Why can't other speed regulating motors do it?
A: This is because other speed regulating motors adjust their speed by controlling the voltage phase. That is to say, when the speed decreases, the input current of the motor will increase, and when the speed increases, the input current of the motor will decrease. Adjust the operating speed in this way. However, during the rolling operation, due to the influence of gravity, the motor will actually run at a faster speed according to this set value. Therefore, except for the two series of motors I just recommended, most speed regulating motors will make a judgment that the motor is running faster than the set speed, and automatically reduce the input current of the motor. Think about it, what would happen to the work object in this way?
Q: What will happen? Let me think... Since the motor is driven by gravity, even if the current is reduced, it will not slow down... That is to say, the motor will be in a state where almost no voltage is applied. In this case, the output shaft will be in a FREE state, and the workpiece will fall off?
A: Yes, that's right! But the DC brushless motor can be used for rewinding operation. This is due to differences in construction. Do you know the structure of DC brushless motors?
Q: The DC brushless motor uses permanent magnets on the rotor to turn the stator into an electromagnet, which rotates the rotor through the alternation of N and S poles!
A: That's right! That is to say, DC brushless motors maintain the set speed by switching the polarity of the stator's electromagnet. So, stable speed control can also be achieved during the rolling operation. However, during the rolling operation, the output shaft of the motor will be driven to some extent due to the influence of gravity. At this point, the permanent magnet of the rotor will become a generator, causing the motor to generate reverse voltage and recoil onto the driver. At this time, the electricity is called "regenerative power". If a drive without the ability to absorb "regenerative power" is used for unwinding, it will cause damage to the drive.
Q: I see. That is to say, the BX series of DC brushless motors has the ability to absorb regenerated electricity!
A: Yes! But to absorb regenerated electricity, it is necessary to use the regenerator in the optional accessories. As long as a regenerator is installed, the regenerated electricity can be converted into heat and released. However, there are certain limitations to the release capacity, so it is necessary to calculate the amount of regenerative power that will occur based on values such as torque, revolutions, operating time, and operating cycle.
Q: How about this! Although customers can also calculate the approximate regenerated electricity through calculation formulas, we also provide free calculation services as long as they call us.
A: Yes, that way customers don't have to trouble themselves with calculating.
Q: Alright, then I will immediately confirm the torque, speed, and operating cycle with the customer.

XI.What is the difference between electronic brakes and mechanical brakes?

Q: What is the difference between a brake used in conjunction with an AC motor and an AC motor with an attached electromagnetic brake? Aren't they all brakes?
A: I said to you, you've been in the company for two years now, how come you don't even know about this? There are also different types of brakes, which can be selected according to their intended use.
Q: A newcomer came to ask me this Q, and for some reason, I was a bit confused. Do you remember that you need a brake when you come to a sudden stop?
A: Yes. Brake is an electronic brake with instant stop function, which releases brake current to the motor to stop it in a short period of time.
Q: So is electromagnetic braking used for up and down driving?
A: Yes, this is because maintaining force is required when driving up and down. And electromagnetic brakes, because they can mechanically lock the motor, can ensure that the position of the load remains unchanged when stopping. Therefore, in addition to driving up and down, it is best to use a motor with an electromagnetic brake for any purpose that requires maintaining the load.
Q: So, can motors with electromagnetic brakes also stop instantly?
A: Of course, but the attached electromagnetic brake motor may experience a 2-3 turn over phenomenon. In contrast, the brake system only has an over turn of 1-2 revolutions.
Q: What does' over rotation 'mean?
A: The number of times the motor rotates from cutting off the power to stopping during rotation is called "over rotation". Taking the over rotation on the motor shaft under no-load conditions as an example, induction motors have 30-40 revolutions, while reversible motors also have 5-6 revolutions. If a reducer is used, the over rotation on the output shaft of the reducer is only 1/reduction ratio.
Q: I see. If only these two convenient brakes could be used together.
A: What are you talking about? Isn't it already there?
Q: Ah?
A: It's the "SB50" brake! As long as this electronic brake is used together with a motor with an electromagnetic brake, can't both load holding and instant stopping be solved? Why did you forget again?

XII. What is the difference between a frequency converter and an AC power input DC brushless motor?

Q: That's right! I forgot again! Okay! Now I can go teach newcomers. Thank you! Ah~I don't know how to A the customer.
A: Huh? What's wrong?
Q: A customer said they want to use a frequency converter or DC brushless motor for speed control. I know about AC speed control motors, but I don't know which one is more suitable for speed control, a frequency converter or a DC brushless motor? So I don't know how to A the customer.
A: So that's how it is. First of all, it is necessary to understand the characteristics of the frequency converter and the DC brushless motor.
Q: What are the characteristics of the frequency converter?
A: By combining the frequency converter with a three-phase 220V AC motor and changing the power frequency, the speed can be controlled. When connecting, simply connect the power supply to the three-phase motor and perform simple speed control.
Q: Oh, it's really simple. However, I heard that setting up the frequency converter is very complicated, so is it still inconvenient?
A: For example, when using a frequency converter to control the voltage by adjusting the frequency, if the applied voltage at low speed is set to a low value, the motor speed may not produce torque at low speed.
Q: How about this! Does this mean that when preparing the motor and frequency converter separately, it is necessary to change the settings?
A: Yes. It's not that there's no need to change the settings. However, if it is our frequency converter combination, because the settings that can fully utilize the motor characteristics have already been set, customers can easily use it.
Q: So that's how it is. So if you want to do simple speed control, can you use a combination of frequency converters?
A: It's not like that. Don't worry. There are speed control motors and DC brushless motors, right? It can not only save energy and space, but also control speed with smooth torque. It is necessary to know their respective characteristics in order to introduce them to customers.
Q: Save energy? Save space? Steady torque?
A: So let's talk about saving space first. Strong permanent magnets are used in the rotor inside the motor. So not only can it have high power, but the motor can also be miniaturized, achieving the effect of saving space.
Q: Really! DC brushless motors are really small and thin in size.
A: Yes. So it can be very helpful for reducing the volume of the device.
Q: So that's how it is! But will a smaller size make it easier to generate heat?
A: I won't. DC brushless motors will perform current control and only flow the necessary current when necessary, so not only is it efficient, but it can also save energy.
Q: I see. And the speed of load changes is very small, so a certain torque can be maintained from low speed to high speed.
A: Yes. Are you also well aware of the advantages of DC brushless motors.
Q: Hmm. The combination of frequency converter and DC brushless motor each has its own advantages, and now I don't know which one to recommend to customers
A: This is simple. Just remember their respective characteristics and suggest using the most suitable product for the customer's device.
Q: I see. I need to reply to the customer quickly. Thank you very much.

XIII. Can you tell me the difference between using a stepper motor and an AC servo motor?

Q: Look, look, I received a customer's request for dependency!
A: Not bad, it seems that you are really working hard. Is the selection okay?!
Q: Well, the customer's purpose is for positioning control, so both stepper motors and servo motors should be usable. But which one should I choose? I'm worried about it
A: Which institution is the customer using it for? What is the operating mode?
Q: It is used for handling on pulley mechanisms. The amount of movement and positioning time required for each transportation is very short. In this case, should we choose servo motors that are good at high-speed operation?
A: No, no, it's better to use a stepper motor in this situation.
Q: Is that true? Why?
A: This is because the customer is using a "pulley mechanism"!. Compared with stepper motors, servo motors allow for smaller inertia, making them less suitable for use in mechanisms where the load inertia increases, and pulleys belong to this type of mechanism. When using a servo motor, it is necessary to adjust the responsiveness of the motor based on the magnitude of the load inertia, which is called "gain adjustment". But when used on mechanisms such as pulleys where the inertia of the load increases, the responsiveness cannot be improved.
Q: Is that so? But even for pulley mechanisms, as long as the workload is light, the inertia is also small, and it should be able to achieve a certain level of responsiveness!
A: Doesn't the belt of the pulley mechanism stretch and contract? Mechanisms with poor rigidity like this are prone to instability due to load inertia, making it difficult to make gain adjustments to improve responsiveness.
Q: So there are things that servo motors can't do
A: At this point, because the stepper motor can be easily used without gain adjustment, it is very convenient to assemble the equipment.
Q: I see
A: Also, isn't the operation mode requested by the customer this time very short in terms of movement and positioning time? Although servo motors are closed-loop controlled and can monitor their movements at any time, the required setting time for such control is reflected through the so-called "delay" phenomenon. And stepper motors operate synchronously based on pulse signals, so there is basically no "delay" phenomenon like servo motors.
Q: So, what if it's in the case of a long amount of movement?
A: When the movement is long, it is more advantageous to choose a servo motor with the highest speed. For example, it is more suitable to perform positioning operation with a large amount of movement on screw mechanisms with shorter lead. Due to the strong rigidity of the mechanism, the responsiveness can be improved through gain adjustment, thus fully utilizing the strengths of servo motors.
Q: So, when selecting, in addition to considering the characteristics of the motor itself, the rigidity and other structural features should also be taken into account, right?
A: Exactly so. When choosing a motor, the first thing to do is to master these key points. However, don't forget to accurately calculate the selection. Be sure to confirm whether the motor truly meets the action requirements required by the customer.
Q: Thank you, I understand now! Your "responsiveness" has always been so clear, no wonder there is no need for "gain adjustment".
A:?

XIV. Introducing to you the driving method for making stepper motors more stable

Q: It's finally time for the exhibition! There are many As coming to visit.
A: This is an opportunity to fully utilize our knowledge. As the personnel responsible for explaining stepper motors, we must work hard today to ensure that our As return with a full load.
Q: Yes!
Q: Welcome (to As)! What kind of stepper motor are you looking for?
A: We often use stepper motors because they have a positioning function, which is very convenient. We also want to use this type of motor on the designed equipment, but with minimal vibration. Do you have any suggestions for motors?
Q: (For As) Is that so. If that's the case, what do you think of the 5-phase stepper motor combination RK series? Due to its smooth driving function, the vibration is relatively low. And using one switch can suppress vibration.
A: That's really great! But to what extent can it be improved?
Q: (For As) We have demo machines available, please try them out to experience the different vibrations at low speeds. Right side B is the operation at a full step angle of 0.72 degrees. Left side A is operating under smooth driving. What do you think?
A: It's completely different! The effect seems to be good. Also, I have heard of micro step level drivers. Is there any difference between this and others?
Q: (For As) The so-called micro step drive refers to the function of dividing and reducing the basic step angle of the stepper motor by 0.72 ° without mechanical elements such as reduction mechanisms. For example, under a 1/10 setting, each pulse is 0.072 'STEP. When each pulse is input, the step angle is subdivided, so the motor can operate smoothly, which can greatly reduce the vibration of the motor. However, when setting the step angle to 1/10, if you want to operate at the same amount as the basic STEP drive, you must set 10 times the pulse amount and frequency.
A: Setting the step angle to 1/10 requires 10 times the pulse amount. So that's what it means.
Q: (For As) The so-called smooth driving function refers to the ability to automatically perform micro step level driving without changing the pulse input setting.
A: I see. Smooth driving enables easy implementation of low vibration function without changing the settings of the upper controller.
Q: (For As) That's exactly the case.
A: I understand now, thank you. But there is still one place that I am not very familiar with.
Q: What is (for As)?
A: Microstep level functionality can achieve smaller STEP, I understand that. But isn't the motor of the deceleration model also capable of subdividing step angles? What is the difference in usage?
Q: (For As) Firstly, the micro step driver can reduce the step angle. However, there are still loads such as friction, as the subdivision of step angles in electrical aspects does not necessarily guarantee the accuracy of segmentation. In addition, the torque of the motor will not change. Microstep level driving is mainly a function of suppressing vibration.
A: Oh? What about the motor of the deceleration model?
Q: (For As) The motor of the deceleration model is finely divided into step angles in mechanical aspects, which can improve positioning accuracy. It can also achieve low vibration. The main reason is not only to reduce the vibration to one of the deceleration ratios, but also to ensure that the output shaft of the motor unit and the deceleration type motor operate at the same speed. As the speed of the deceleration type motor increases relatively, the vibration frequency of the motor can be avoided. However, due to the use of a deceleration mechanism, the available rotational speed has also been relatively reduced.
A: I see.
Q: (For As) Additionally, the advantages of the deceleration type motor are the ability to significantly increase torque and drive with greater inertia.
A: So the motor of the deceleration model reduces the pitch angle through mechanical structure, so its advantage is that it can significantly increase torque and drive with high inertia!
Q: (For As) That's exactly the case. However, depending on the type of gearbox, please note that backlash may occur during forward and backward positioning. Simply put, it is necessary to select micro step level drivers or deceleration type motors according to the requirements and specifications of the equipment. If selected properly, it can further enhance the overall specifications of the equipment.
A: So that's how it is. After returning, I will try to choose the most suitable motor for the equipment as soon as possible!
Q: (To the A) Thank you very much. Please make sure to consider our company's products. Welcome to make more use of 'Selected Services'. Yes, our company also provides As with 'selection services'. If you have already made a preliminary decision on the operating conditions of the equipment, you can easily inform us of the specifications of the mechanism by fax. Our company will conduct selection calculations for you and recommend the most suitable motor. Welcome to make more use of it.
A: Really? Will your company help us with the calculations? That's really good. We need to quickly intensify the discussion after returning. Thank you!
Q: (For As) Yes. We look forward to hearing from you. Thank you very much today.
Q: (Internally) When I just talked to the A about the differentiation of smooth drive function, micro step drive, and deceleration motor usage, the A was very happy. Moreover, it seems that we are about to entrust our company with the selection.
A: Is that so? That's really good. Did you tell the client that in addition to fax, they can also use online delegation?
Q: No, there isn't
A: If you remember to introduce it, you can also choose from online commissions. Fax delegation is one method, but there are six delegation formats available online, including ball screws, belts, pulleys, etc. As only need to input the conditions in numerical form and send them back to us, and they can easily complete the delegation selection! (The selected service can be entrusted through fax or the internet.)
Q: Yes... thank you. I'll go tell the client quickly.

XV. It turns out that pulse signals also have voltage specifications!

Q: A A has inquired about pulse signals and asked me if 24V pulse signals can be used in conjunction with stepper motor drivers. I used to think that pulse signals were just the on-off switching of 5V voltage...
A: Have you encountered another difficult problem? Okay, before explaining the issue of pulse voltage, let me first explain the basic specifications of pulse signals to you using the Chinese version of the Comprehensive Catalog 2004/2005 version!
CW (pulse), CCW (direction of operation) pulse signal input pulse waveform
Please refer to page C-93 of the 2004/2005 edition of the Chinese comprehensive catalog for the pulse waveform of the driver pulse input section. ）
The above figure shows the amplitude, voltage unit, and width of the rising and falling edges of the pulse signal. Any pulse signal that meets the above conditions can be used in conjunction with the driver of a stepper motor.
Q: So that's how it is. I also often browse the directory, it's strange why I didn't notice ... Huh? But the voltage is not indicated in this picture ..
A: Yes, so please take a look at this picture next!
■ Input circuit and wiring example
Pulse generator output
open collector 
Internal circuit of the driver
200Ω
10-20mA
Please refer to page C-93 of the 2004/2005 edition of the Chinese comprehensive catalog for input circuits and wiring examples. ）
Q: I know this picture! This is the wiring diagram that connects the input circuit using an optocoupler to the open collector output! The contactless AC speed controller also uses the same diagram.
A: Yes, this schematic diagram is an example of the wiring between the driver and pulse generator of the 5-phase stepper motor RK series ※. The CW pulse/CCW pulse signal input part is an optocoupler input method.
Q: What are the characteristics of optocoupler input?
A: An optocoupler is an electronic component that uses input current to convert electrical signals into optical signals for communication. Because it is not easily affected by noise, it can convey signals more accurately. However, it must be noted that there are certain limitations on the magnitude of the input current.
Q: I see.
A: The pulse input part of the RK series is shown in this figure and requires a current of 10mA to 20mA. If it is the 5V pulse signal you mentioned, it can be directly connected to the driver without connecting the resistor (R1) in the diagram.
Q: So, under what circumstances is this resistor (R1) used?
A: If a voltage exceeding 5V is connected to V0, the resistor (R1) shown in the diagram is required. For example, if the A's question is to connect a 24V voltage, a resistor should be connected to maintain the current value of the optocoupler within the range of 10mA to 20mA.
Q: So that's how it is! So, how should we calculate the resistance value?
A: For example, when inputting a current of 15mA, it can be calculated according to the following formula.
R1=V0-1.5 (V) (Note) 0.015 (A) -220 (Ω) R1=0.015 (A) V0-1.5 (V) (Note) -220 (Ω)
The voltage drop part of the optocoupler.
Q: Does this formula use Ohm's theorem?!
A: Yes, all of these need to be remembered in advance. The contents I just explained to you are all recorded in the specifications section of the drive. It's best for you to confirm as well. (Please refer to page C-82 of the Chinese version of the Comprehensive Catalogue 2004/2005.). ）
Q: Are there many complex rules?!
A: I won't. If it is the EMP series or SG80301 pulse generator from Dongfang Motor, there is no need to worry about power specifications and it can be easily combined with the motor, so it can be used with peace of mind. Also, do you know that drivers can be divided into single pulse input and double pulse input?
Q: Is dual pulse input more efficient than single pulse input Ah。 What are the differences exactly?
A: Actually, it's not a high-performance issue. Dual pulse input is to input pulse signals into the CW input section and CCW input section respectively to make the motor run in the clockwise and counterclockwise directions. Single pulse input, on the other hand, involves inputting a pulse signal into one input unit and switching the direction of operation using another input unit. The single pulse input and double pulse input of the driver should be set according to the signal output of the pulse generator.
■ Dual pulse input mode
|Forward Pulse (CW) | ON OFF|
|Reverse Pulse (CCW) | ON OFF|
|Motor action | Clockwise direction | Counter clockwise direction|
Q: I see, now I finally understand. Thank you so much. Now I finally have the confidence to explain to the client. I'm going to contact the client right away. Ah。 (Falling)
A: Let me tell you, don't panic, calm down!

XVI. Will the over rotation of the motor vary depending on the type of motor?

Q: I have a very basic Q to ask. Actually, I am not very familiar with the "over rotation" of motors .
A: Where is it?
Q: What I want to ask is, is the amount of rotation from cutting off the power to completely stopping the motor when I want it to stop called "over rotation"?
A: Yes. By the way, the larger the inertia of the load on the motor shaft, the greater the amount of over rotation.
Q: Huh? Does that mean there is a relationship between the rotational speed and the inertia of the load?
A: Yes, let's take the example of a truck with goods and a truck without goods! If the truck carrying goods stops urgently at the same speed, will the distance until it comes to a stop become longer! Similarly, the larger the inertia of the motor's load, the greater its over rotation.
Q: I see! So, what is the approximate amount of over rotation of a motor in general?
A: Depending on the type of motor, the amount of over rotation also varies. The over rotation of an induction motor under no-load conditions is approximately 30-40 revolutions.
Q: Will the amount of over rotation vary depending on the type of motor?
A: Yes. For reversible motors, the over rotation is only about 5-6 revolutions.
Q: Why is that? Why is the over rotation of reversible motors smaller than that of induction motors?
A: Isn't a reversible motor equipped with a simple brake for instantly switching the direction of motor rotation? So, compared to induction motors, the amount of over rotation will be much smaller.
Q: So that's how it is. So, what is' simple braking '?
A: There is a brake pad on the rotor of the motor, and the brake pad is pressed against this plate.
Q: Oh~So, over rotation refers to the number of rotations of the motor shaft? So, what about the amount of over rotation when using a gearbox?
A: That's a very good Q! The amount of over rotation is indeed reflected by the speed of the motor shaft. So, when using a reducer, the amount of over rotation of the output shaft is equal to the "1/reduction ratio" of the reducer.
Q: So, if a reducer with a reduction ratio of 1:3 is used on an induction motor, the amount of over rotation of the output shaft of the reducer is 10-13 revolutions, right?
A: Exactly so. The larger the reduction ratio of the gearbox, the smaller the amount of over rotation. However, due to the speed being 1/reduction ratio, the speed will slow down, which means that production efficiency will decrease. Therefore, customers must pay full attention to this point. If you want to reduce the amount of over rotation without changing the speed, you can use a motor with an electromagnetic brake or a brake.
Q: I know that! It refers to electromagnetic brake motors that can mechanically maintain the position of the motor and brakes that use brake current to instantly stop the motor!
A: Yes. The over rotation of the motor with electromagnetic brake is about 2-3 revolutions, while using the brake, it is only about 1-1.5 revolutions.
Q: I see. I didn't expect that from the perspective of over rotation, it can also be found that it is affected by the type of motor.
A: Therefore, when selecting a motor, it is necessary to distinguish it according to its intended use. In the future, when customers come for consultation, it is important to carefully confirm their usage conditions and introduce suitable motors to them. You must keep going!
Q: Okay! I will definitely try my best. Thank you!

XVII. Please advise me on effective methods for setting up fans!

Q: It's really cold! It's snowing outside. I'm the most afraid of the cold....
A: Actually, I'm also very afraid of the cold.... But in such cold weather, a customer just asked, "Although a cooling fan is used, the temperature inside the control panel is still very high. I really don't know what to do
A: If there are multiple drives in the control panel and appropriate heat dissipation measures are not taken. Even in winter, the temperature inside the controller may still be high. So what are the countermeasures?
Q: It may be due to insufficient air volume relative to the temperature rise inside the control panel, so I suggest the customer confirm the usage conditions and analyze whether the fan currently in use is suitable.
A: Not all of them! However, even if customers use fans with high air volume like the MRS series, if the setting method is incorrect, it may not be able to fully utilize the characteristics of the fan. Take the situation of this customer consultation as an example! The cooling method of exhausting the hot air inside the control panel to the outside is called "ventilation cooling". Do you know what issues to pay attention to in this situation?
Q: This... I don't know anymore.
A: Let me tell you, it's not just the motor, you also need to enrich your knowledge of fans! Firstly, since it is "ventilation", it means that there must be air inlets and outlets inside the control panel, namely the "intake port" and "exhaust port". This is actually the same principle as promoting room air convection. The focus here is on the size of the intake/exhaust ports. If the air outlet can be opened as wide as possible, it can promote more air flow and achieve effective ventilation. This is because pressure loss can have a direct impact.
Q: What is pressure loss?
A: The so-called pressure loss, in short, refers to the degree to which air is difficult to flow. The smaller the air channel ("flow path"), the greater the pressure loss.
Q: I see, so it's better to open the intake and exhaust ports as wide as possible!
A: That's exactly what it means. It seems that you have already started to understand! However, even if the intake and exhaust ports are wide open, it is difficult to achieve the desired effect if the control panel setting method is not ideal. For example, the distance between the wall and the control panel is related to this. Understood?
Q: Ah! Due to being blocked by walls, the airflow will decrease. That is to say, the wall is the pressure loss, causing a decrease in air volume, right? So, how much distance should be left?
A: It is best to be above 100mm. If not possible, customers should also be reminded to leave at least the same distance as the thickness of the fan. You may refer to this information.
Q: Really, the information is also very easy to understand.
A: There are also more effective setting methods that can be suggested to customers!
Q: Ensure the size of the intake and exhaust ports, as well as the distance between the wall and the control panel