SCR Motor Controller

[adamq]

You're right. Which made me realize it has to be something I did.

And it was. I forgot to attach the negative side of the capacitors to the negative bus. Stupid.

Minder, thank you so very much. You are the only reason I got this working!

Learned a lot about DIACs, TRIACs and some more about resistors and capacitors.... And a a good lesson was learned about paying attention and dilligence.

 

[yoho2chn]

Sorry guys bumping up this post. I recently bought a device which is running similar circuit but is designed for 220VAC. I am thingking how I could modify it to run on 110VAC instead of plug it into step up transformer.
Here is the PCB look. The very left side(bottom red&yellow wire) goes to DC brushed MOTOR

 

[duke37]

It should run on 110VAC without a transformer but you may need to reduce the value of the rheostat to get up to full speed.

 

[Josh47]

This idea, it is easier to build a Triac controller than a SCR style which requires the SCR's to be inside of a bridge.

M.

Can I use this circuit for a 90vdc motor. Let's say I need 10 amps max would I have to parallel triacs ?

 

[Minder]

Just use a suitably rated Triac and bridge for the 10amps.
M.

 

[Josh47]

Okay awesome now how will this circuit affect the torque of the motor will it be significantly less?
Thanks

 

[Alec_t]

how will this circuit affect the torque of the motor will it be significantly less?

Yes. Since the average current through the motor is reduced the torque will likewise be reduced.