I have a signal which is a square wave at about 25000Hz. The high is 12V, the low is 0V or ground. I have a dual rail supply. I want to change the signal so it swings between +12v to -12v.
I use an LM358 op amp as a comparitor, powered from the + and - rails. I put 2V relative to ground on the inverting input. I was expecting the output to swing either way (as on my schematic), but it doesn't - it is constant at -12V. I have tried putting the potential divider between the +/ground and using different resistors between + and -, so that it is just a few volts above ground, but the output is not moving.
Relatively new to this, have I done anything wrong?
Any help most appreciated!
John
I use an LM358 op amp as a comparitor, powered from the + and - rails. I put 2V relative to ground on the inverting input. I was expecting the output to swing either way (as on my schematic), but it doesn't - it is constant at -12V. I have tried putting the potential divider between the +/ground and using different resistors between + and -, so that it is just a few volts above ground, but the output is not moving.
Relatively new to this, have I done anything wrong?
Any help most appreciated!
John