Mini trim pot to big potentiometer
I tried to wire in a big potentiometer in place of the mini trim pot that came with my heater , the trim pot looked to me like it only used 2 out of the three legs , so I wired in the big potentiom...
Forum Discussion
Tom_M wrote:
Connect all three pins. Circuit board is double sided so traces can be on both sides.
So you didn’t remove the small pot? You can’t just put two equal sized pots in parallel since the resistance will be reduced significantly, especially if you leave the on-board one turned anywhere but to 8k ohms. Best case you get 4kohms max.
You can get close if you use a much larger value for the added one. For example if you parallel a 100kohm pot, twist the small one to 8k and the large one to 100k you will end up with 1/(1/8 + 1/100) = 7.4k max down to 0 when you turn the big pot all the way down (leaving the small one alone).
However it would probably be simpler to just remove the small one.
Also since there are traces on top, did you confirm there isn’t one to the 3rd pin there?
