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TerraMex · 03-26-2003, 04:03 AM

I've made a couple of PWM circuits, didnt have that problem, i think you just bought crappy rheostats. Althou almost all rheostats work with a single turn, well not even "a" turn, about 5/6 of one, and a decent one is pretty linear.

usually a multiturn one is different :

http://www.jprelec.co.uk/docs/order_...NONE&TEMP=NONE

Or with a similar design.

And another thing, the circuit on that page (Brian's circuit) uses a 10k Ohm variable resistance (R3), not a 5k, maybe thats part of the problem.

03-26-2003, 04:03 AM	#3
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	I've made a couple of PWM circuits, didnt have that problem, i think you just bought crappy rheostats. Althou almost all rheostats work with a single turn, well not even "a" turn, about 5/6 of one, and a decent one is pretty linear. usually a multiturn one is different : http://www.jprelec.co.uk/docs/order_...NONE&TEMP=NONE Or with a similar design. And another thing, the circuit on that page (Brian's circuit) uses a 10k Ohm variable resistance (R3), not a 5k, maybe thats part of the problem. __________________ "we need more cowbell."