PWM controller for heater blower motor

[Arthur 13]

Hi all. 

 

I was wondering. My last transistor in my heater resistor unit thingy lasted about 30 seconds. My motor might be pulling too much current. But before checking that and ordering new transistors ones again, did anyone even used or considered to use a PWM controller? I'm a bit fed up with it. I dropped the round earth basterd thing last time and it disappeared into another dimension. The lever on your dash is nothing more then a pot.meter, right? Could that be used to steer a pwm motor controller like in this link. Anyone happened to know the resistance bandwidth of the dash lever potentiometer? 

 

https://www.conrad.nl/p/kemo-m171-vermogensregelaar-module-9-vdc-12-vdc-24-vdc-191273

 

 

[welshpug 1,666]

knob on the dash is not a potentiometer, just a rotary switch.

[Arthur 13]

I should probably have mentioned I have a mark 1 205. (Item 1)

 

 

 

[Thijs_Rallye 87 4 Cars]

Take out the heater motor and check how freely that spins. Likely the bearings are all gunked up. Might be just a case of taking off the fan and re-lubing the motor.

 

 

[Arthur 13]

Yes. It’s not new ideed. It needs more then 10A full power

Edited October 7, 2020 by Arthur

[wicked 105 3 Cars]

I did replace the transistor with a PWM module in my trackday car and you can make it work, but be aware that the PWM polutes your 12V with switching noise. 

In my case it makes that I cannot use my shift light (picks up alternator frequency) if I turn on the blower. It does not have a sound system, but I could imagine that if you have, it could impact the sound quality...

Better fix the blower itself...

 

 

Edited October 8, 2020 by wicked

[Arthur 13]

Yes probably better. I need to order new one again. How much A should the motor ask for? I can't find the data, but I see 250 Watt is quite common, which would make it about 20A. My multi goes to 10.

[Thijs_Rallye 87 4 Cars]

3 minutes ago, Arthur said:

Yes probably better. I need to order new one again. How much A should the motor ask for? I can't find the data, but I see 250 Watt is quite common, which would make it about 20A. My multi goes to 10. 

According to here: https://www.besteonderdelen.nl/vdo-1736888.html they are rated at 115W. So assuming worst case 115 / 9 ≈  12,8 A.

[Arthur 13]

Hi All

 

I took a look at my blower motor first. It did run quite not right. It's from the stone age though. No bearings. I think it's done.

 

The collector is worn a lot so I don't know if it's worth overhauling. but are there any alternatives?  It's a bosch 0 130 063 027.  I can find some new ones, but they are very expensive and you still have something from the stone age. Are there any alternatives?

 

[Thijs_Rallye 87 4 Cars]

I'd give it a go with new brushes and oiling the bearings. Might be from the stone age but it has already functioned for 25+ years.