Pulse Width Modulation (PWM) speed controllers with coreless motors.

[Christopher_R]

Greetings people.

 

I am planning to put together a DC controller for my trains (yes, I still run DC OK😁).

 

I have the means of getting down ready made circuits and DC speed controllers to assemble which almost all of them come with Pulse Width Modulation (PWM). 

 

I have read that controllers with PWM can harm coreless DC motors and I'm wondering now as many N scale trains now come with them now (I have one of them).

 

Does anyone have experience in this situation? Would like your input and thoughts on this.

 

Thanks in advance!

[roadstar_na6]

I think it depends on the PWM frequency and I'm also curious about which one would be one that doesn't harm corless motors and causes no buzzing from any japanese motor.

[inobu]

I think the issue is more so how or what the PWM is doing. The problem stems from the trains lighting.

They use the PWM to send enough pulses that illuminates the lights without driving the motor. This

causes the motor to heat up. If the controller is off there's no issue.

 

Inobu

[roadstar_na6]

The links at the end of this thread might also help a little, but I'm still not 100% what would be the best frequency

 

 

Edited March 8, 2021 by roadstar_na6

[inobu]

In essence it is the rate in which the pulses are still close enough together to be perceived as a constant on state.

You need an oscilloscope to be able to dial in the frequency to its slowest form.

 

Inobu

[roadstar_na6]

So the goal would be to have it as slow as possible?

[inobu]

1 hour ago, roadstar_na6 said:

So the goal would be to have it as slow as possible?

Part of the problem is finding the slowest rate that induces the least amount of heat but this is based on

the motor type as well.

 

This is just me talking.....It's a lot of effort to turn on lights for a sitting train. I rather have 3 or 4 DCC trains

than 30 DC trains. Those were the number of DC trains I had when I started DCC. I converted the ones I likes the most.

I still haven't converted all of them and don't think I ever will. Once you convert to DCC there are too many other fun things to do.

 

I refused to go DCC for 2 years when I did I just shook my head....that's the case with most of us here.

 

Just saying...

Inobu