EcoRenovator - View Single Post - DIY thermal differential controller (solar hot water pump controller)

Xringer · 10-05-09, 01:28 PM

Looking at that diagram..

The thermistors form a simple (2.5V) voltage divider. So, you could use two
5k or two 10k etc. As long as they were nearly the same resistance
(when at the same temperature).
If they weren't the same, that Adjust Pot can trim things out.

I think my old controller could easily be tweaked in using a small pot
on one of the input lines. (If it was indeed out of balance).

10-05-09, 01:28 PM	#27
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Looking at that diagram.. The thermistors form a simple (2.5V) voltage divider. So, you could use two 5k or two 10k etc. As long as they were nearly the same resistance (when at the same temperature). If they weren't the same, that Adjust Pot can trim things out. I think my old controller could easily be tweaked in using a small pot on one of the input lines. (If it was indeed out of balance).