Op Amp Square Wave Generator - Help

[AustinTxBob]

I'm sure I am doing something wrong here.  I've tried a couple of different op amps and a few different schematics and I cannot get any kind of oscillation.  Right now I have a mcp6002 on the board with the value of the components shown in the other pic. I'm probing between ground and the output channel of the amp.  Any help would be appreciated.  Thanks!

[basinstreetdesign]

What power arrangement do you have?  What voltages?

If you have single supply with negative power pin of the op-amp grounded then the answer is simple.  There is a resistor missing between the non-inverting input of the op-amp to power.  It should be the same as R1.  This will bias the input up midway to VCC to allow the inverting input room above and below it so it will switch.

If you have bipolar supplies then I dont know...what else can you tell us about the environment.

[starphot]

  Here's the op-amp basic square wave generator I took out of an app manual and tried it out for you using a TL082. Yes, you are missing some things. Single supply, your MCP6002 has a range of 1.8 to 6volts on the supply. About 1.7 KHz with components shown.



Joe

[AustinTxBob]

Thank you very much.   It makes sense to me now as to how it works as well.

[alexanderbrevig]

relevant https://www.eevblog.com/forum/beginners/op-amp-square-waves/