OP07 circuit output voltage?

[Easy peasy]

it appears the fault is not with the OP07 - you'd be better off looking for faulty solder joints etc ...

 

[steve_rb]

I have an idea:

I want to install a 2.75 zener diode between point X and ground. This way I will force point X to stay at 2.75 v and will have a stable pre-start condition. I will not be able to go to start condition but at least will prove stable 2.75 v at point X is the problem. I want to install this zener diode but what to be sure I will not make any extra harm to the circuit. Would you confirm installing this zener diode will not cause any extra damage to the circuit?

 

[Easy peasy]

point X is not defined anywhere I can see - do you mean the o/p of the OP07 ?

the o/p current is 30 to 20mA and the chip would appear to be able to survive this - so you can try what ever you want - but more likely a good physical inspection with a bright light - i.e. a good look - will find the issue - if older than 7 years solder joints as high on the list of probably faults ...

 

[steve_rb]

point X is not defined anywhere I can see - do you mean the o/p of the OP07 ?


Yes. At post #1 you can see it. It goes to another board (see attached red circled)

 

[steve_rb]

Simple schematic of the whole system is attached. Voltage of pin3 manually set depending what Kv we want at the end. OP07 output adjust the thyristor fire angle to generate proportional kv at the end. From produced Kv at the end a feedback returns to pin2 which will be equal to pin3 if output Kv has reached proper voltage. No more increase of the OP07 output and fire angle will happen from this point which means output Kv is stabilized at the desired value.

Considering what I said what would be output of OP07 if pin3 voltage changes between 2.5-6 v?