Electronics 2000

Posted: **Thu Sep 25, 2014 2:16 pm**

Maybe I am doing something wrong, or misinterpreting my readings, would someone with more experience please look at this OP AMP circuit and explain my results please? Localised image of the circuit, and full schematic hopefully attached, many thanks. The localised image is from the first page of the full schematic linked to below, IC3 area, AC balance control.

http://www.chriswilson.tv/schematic.pdf

: TIG_ac_BALANCE.JPG (136.32 KiB) Viewed 2952 times

Posted: **Sun Sep 28, 2014 3:56 pm**

It looks to me to be a negative feedback circuit, what is it for? I'm thinking it is a welder?
What is the fault? When you switch it from AC to DC do you get a change in voltage at pin 26 on plug 1 ?

Electronics 2000

Are these voltage measurements feasible??

Are these voltage measurements feasible??

Re: Are these voltage measurements feasible??