PWM DC Speed Control for heater fan to replace resistor

[tclark]

So a few years ago in another van I looked into
a few PWM controls to rid the front heater fan of the resistor pack
http://www.thesamba.com/vw/forum/viewtopic.php?p=2659721#2659721

But at the time i went for a quick fix well another van another dash R&R so this time I think I want to try PWM controls similar to this

http://store.qkits.com/moreinfo.cfm?Product_ID=1644

But if anyone has installed a working PWM I'd luv to use a known to work solution that just works I'd like to hear about it ...

-,model number with a separate rotary control
-location for the unit since its goona have a pretty big heat sink
-any pics of install
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89 Westy with TDI AHU 1.9 manual lots of mods
85 GL 1.9, auto (for sold)

[squeegee_boy]

I used the predecessor to this one:

http://www.robotshop.com/ca/productinfo.aspx?pc=RB-Cri-28&lang=en-US

The new one has changed the board layout, but the specs are the same.

Whatever you get, be certain the it's a "high frequency" unit. If it's not, your fan will make a screeching racket unless it's running at full speed (ask me how I know).

"High frequency" refers to the PWM switching rate of the controller. Slow units cause audible feedback from the motor they're controlling. If it doesn't say "high frequency" in the description, it's not.

The Quality Kits one you linked to has a switching speed of 100hz, which is very audible.

This one (for example) is a much better choice; it switches at 18khz:

http://criticalvelocity.com/item.php?itemid=spdc13


Robyn

Edit: Oh yeah, I mounted it behind the glove box and extended the blower power leads to reach. That way it has a good bit of open air, but it only gets mildly warm under use.
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1984 FrankenSyncro Westy. EJ25 RMW kit
1971 Super Beetle with an EJ22. Oh yes. Daily driver

[gl98115]

[tclark]

[squeegee_boy]

[squeegee_boy]

[tclark]

[squeegee_boy]

[tclark]

[squeegee_boy]

Hmm, cool. Mine was 9.something brand new.

Robyn
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1984 FrankenSyncro Westy. EJ25 RMW kit
1971 Super Beetle with an EJ22. Oh yes. Daily driver

[tclark]

So I am gonna order 1 of these "Shanghai Baikong Electric Motor" same as used in the DIY
autospeed.com article 30Khz, 350w pwm units
lots sold & feedback looks good so somethings from here work
http://stores.ebay.com/Kimke-Wei/_i.html?_nkw=+12V...=948138090

I confirmed
1) the maximum output watts
2) the output frequency
hi
Maximum 350W.
30K

Best regards,

- kimke-wei-usa
Can i verify the wiring here
Assume color are as per the pwm controller from Shanghai Baikong Electric Motor

1) take the brown wire going from the star ground to the motor & connect that to (white) 1 pole for the motor on the pwm controller

2) take the yellow/black wire used to control the 3rd hi speed & connect that to (yellow) other pole for the motor on the pwm controller

3) Run a new ground wire from the star ground &
connect that to (Green) Negative ground connector for the power on the pwm controller

4) take the Red/Black power wire used to feed the existing fan switch & connect that to the (Red) POSITIVE connector for the power on the pwm controller

5) de-solder the 3 wires on the POT & replace with appropriate length wire & crimp on connectors... remote mount the pot behind the heater face plate

if the fan spins the wrong way reverse 1 & 2 ?
_________________
89 Westy with TDI AHU 1.9 manual lots of mods
85 GL 1.9, auto (for sold)

[tclark]

the ShangHai Baikong pwm arrived to day
I bench tested it connect to the std resistor pack & then to the pwm

But before that I pulled off the pwm cover
http://members.shaw.ca/trclark/vwvan/pwm/PWMBoard1.JPG
http://members.shaw.ca/trclark/vwvan/pwm/PWMBoard2.JPG
Note how they use the metal band & fasten the chip set to that & use the entire case as the heat sink, but I ran for 1hrs & the case did not even get warm

then I tested it powering it from a pc 12v dc supply rated at 360watts, 15max amps

at 1/2 speed it pulled just over 3 amps
http://members.shaw.ca/trclark/vwvan/pwm/HeaterPWMhalfSpeed3Amp.JPG

at full pot it was 6amps

hmm why am i not seeing the 9-15amps reported in the other threads ?

the crappy pc dc supply ?

Also I think there is a really high pitched wine at certain voltage level (also occurs with the resistor pack on speed 2) but not across the full spectrum of the pots scale.
I need to get it into the van since the test location already too much gear in there

I wanted to measure the output frequency
but the fluke 88 only works to 1Hz using the RPM/Hz feature but a local tv store has an oscilloscope & if i bring in the unit all hooked up he say $5 to scope it so I'll do that today for FUN ...I need a lfe
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89 Westy with TDI AHU 1.9 manual lots of mods
85 GL 1.9, auto (for sold)

[squeegee_boy]

I tested mine from a spare car battery, because I didn't own a PS big enough. Try that maybe?

As for the frequency, it's a cool academic exercise (sorry, no I don't know how to make the meter do that), but if it were a low frequency unit, you'd know immediately. It's LOUD.

Robyn
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1984 FrankenSyncro Westy. EJ25 RMW kit
1971 Super Beetle with an EJ22. Oh yes. Daily driver

[Thor-bob]

The whine is a by-product of the circuits that control the output to the fan motor. You can rid yourself of this by putting a filter choke between the control and the motor.

It's basically a low-pass filter to get rid of all that high frequency component that makes noise but doesn't do much work. We get this a lot driving 3 phase motors with a Variable Frequency Drive, using shaped DC output. You do have a choice to change the carrier frequency to a higher one, but that comes at the expense of more heat generated in the motor windings (OK with modern motors rated at 50 degrees C or better).

Just sayin'.

Thor-bob

[luVWagn]

[David Marquis]

This thread is very helpful, I stumbled upon it when researching wiper motor info and I am very glad that I did.

My heater has always made that screeching sound. I had always assumed that it was my blower motor, bearings and so on... It has, however, always stopped making the sound when I put the heater on high speed. As was stated in this thread.

I am currently replacing my entire unit with a new combination heater/A/C in dash unit from Small Car Performance. As discussed in the following thread:

http://www.thesamba.com/vw/forum/viewtopic.php?p=7161810&highlight=#7161810

In this thread, Thor-bob stated:
“The whine is a by-product of the circuits that control the output to the fan motor. You can rid yourself of this by putting a filter choke between the control and the motor.”

Aside from the replacement of my original heater unit/blower motor, would I have to replace additional components in order to illuminate this screeching sound?

From what has been stated here I am not certain that this swap will illuminate this screeching sound.
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1989 Westfalia Vanogan GL, 2.1

[luVWagn]

[pushkick]

so its been awhile since this post was started. what pwm controller have you ended up with and how has i worked for you? do you still have the whining noise? where did you mount the contoller? that old resistor creates a lot of heat and the factory mounted it in the plastic blower box.
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i see said the blind man to his deaf dog
i am going to quit smoking and drinking and die a healthy man. gotta laugh
there is no deed to the planet earth
1990 vw automatic camper

[hans j]

I've been thinking about doing this for my sink faucet motor. Would be nice to get it down to a manageable flow that doesn't force water everywhere!
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1986 Canadian Syncro Westy TDI - 1989 Syncro Single Cab - 2001 Audi S4 - 1981 VW Caddy ABA - 1980 VW Caddy EV - 1973 VW T-181

[Altoona]