12Vdc blower to a dimmer - need electrical help!

BlueMan said:

So I just got the 12v DC blower from surpluscenter.com that was being talked about a bit ago. however, the motor is single speed, and I want to hook it up to a dimmer. But I know it's not just that simple.

Now I know enough about electronics to know that a regular AC dimmer for a lightswitch won't work since the interrupted current on an AC dimmer would burn out the DC motor.

is there a special DC motor dimmer out there?

Thanks for the help

Click to expand...

squeakygeek said:

At 8 amps, you're not going to be able to use a regular fan controller. You could make a variable voltage regulator like in the thread I linked. If you split the dual blower into two separate blowers, each would draw 4 amps. In the that thread, there is noted a different regulator that functions the same, but has a max current of 5 amps. You could use two regulators.

Click to expand...

BlueMan said:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=58286&item=3820282526&rd=1#ebayphotohosting

is this the kind of power transistor you're talking about?

Click to expand...

BlueMan said:

Ok, i've done some more homework.

So the PWM circuit has to be AT LEAST 8 amps, but can be over. Additionally, you have to hook it up to a LINEAR controller, not a volume knob which works logarithmiclly.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=2563&item=5903296901&rd=1

how about that PWM switch? do I have the right idea?

Click to expand...