How to obtain the parameters of DC motors?

In summary, you can measure the following parameters using an oscilloscope, voltmeter, and current meter: torque constant, Back EMF constant, Dynamic Resistance, Motor Regulation.
  • #1
bbq_build
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Hello, I appreciate if somebody could help me to resolve this. I bought a geared DC motor from a store. I would like to obtain the following information: Resistance, Inductance, Back EMF constant, torque constant, and the voltage caused by Back EMF when the motor is supplied by a voltage input higher than the recommended one. What experiments do you recommend to obtain these values? Do I need fancy equipment to get these values by experiments?

Even I asked the company, they can only provide the following information (at the recommended voltage): torque constant, Back EMF constant, Dynamic Resistance and Motor Regulation. The guy asked the manufacturer. He said that these are all he can get and he has no idea what they mean. if I supply 4V higher than the recommended input voltage, will these provided values change a lot? Which parameter(s) stay the same?

Thank you
 
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  • #2
Any identifying information on the motor - maker - product number ?
 
  • #3
Just a Tamiya toys motor. The manufacturer does not seem to want to provide all the information.
 
  • #5
They only give the gear ratio. I need the parameters I mentioned for modelling. Any good approach to measure the values?
 
  • #7
Thanks but not sufficient to model it. I need the parameters mentioned in the original post.
 
  • #8
Well I can't really see why you need any of these values but if you want to experiment then you need to build a test bench .

There would have to be at minimum some variety of very sensitive dynamometer , a tachometer , voltage and current meters , an oscilloscope and a finely controllable power source .

Problem is that any transient events like run up time to speed are going to take place so quickly that you won't be able to take reliable readings manually .

Probably best to use a PC to control the experiment and log all the data automatically .

What do you want to use the motor for ?
 
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  • #9
Applying excess voltage may well result in excess current and a burnt out motor. Be a shame to burn up your motor just as you get the parameters you want.
 

Related to How to obtain the parameters of DC motors?

1. What are the key parameters of a DC motor?

The key parameters of a DC motor include voltage, current, speed, torque, and power. These parameters determine the performance and capabilities of the motor.

2. How can I measure the voltage and current of a DC motor?

The voltage and current of a DC motor can be measured using a multimeter. Set the multimeter to the appropriate DC voltage and current ranges and connect the probes to the positive and negative terminals of the motor.

3. How can I determine the speed of a DC motor?

The speed of a DC motor can be determined by using an optical tachometer or by counting the number of rotations in a given time period. The speed can also be calculated using the formula: speed = (voltage x speed constant) / armature resistance.

4. What is the torque of a DC motor and how is it measured?

Torque is the rotational force produced by a DC motor. It is typically measured in Newton-meters (Nm) or pound-feet (lb-ft). Torque can be measured using a torque wrench or by calculating it using the formula: torque = force x distance.

5. How do I calculate the power of a DC motor?

The power of a DC motor can be calculated by multiplying the voltage and current values, or by using the formula: power = (torque x angular speed) / (2 x pi). The power output of a DC motor is also affected by efficiency losses, which should be taken into account when calculating power.

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