I'm trying to build this circuit- the red area is what I'm having problems with:

the red area is what im having problems whit

What is happening is that I have 4.5 volts for like a second then it drops to 3 volts which can't run the op amp.

I did get it to work for a while but then I re-built it on a bigger board and now it drops the voltage too low. what can be the culprit?

Is it the battery or is it the over all design for the circuit that handles the biasing of the voltage?

BTW: I haven't done any electronics in like 6 years so I might have missed something basic.

  • \$\begingroup\$ So, measure the battery voltage and remember that op-amps need power rail connections. \$\endgroup\$
    – Andy aka
    Commented Dec 13, 2020 at 15:31
  • \$\begingroup\$ so my battery is at 9,02 volts. By power rail connections do you mean the + - voltage inputs on my op amp. if so they are connected to + to the battery and - to signal ground \$\endgroup\$ Commented Dec 13, 2020 at 16:25
  • \$\begingroup\$ And where is the battery's negative terminal connected? (A complete schematic including the battery would be helpful) \$\endgroup\$
    – The Photon
    Commented Dec 13, 2020 at 16:28
  • \$\begingroup\$ so the negative is connected to the negative on my solder less breadboard, i can try and put a schematic together quick \$\endgroup\$ Commented Dec 13, 2020 at 16:53
  • \$\begingroup\$ tinyurl.com/y6d9vf86 here is a schematic of my circuit but in this version where i use a "real" op amp the volt is about 1 on the + voltage input. \$\endgroup\$ Commented Dec 13, 2020 at 17:08


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