Electronic – How to amplify the current out of a triangle wave generator

amplifiercurrent

I'm designing a triangle wave generator to power a detector. The triangle wave is coming out at the right frequency (0.4 Hz), but I'm using an LM324 and the detector that I'm driving needs 100 mA to run. I tried connecting the triangle wave output to a 1k resistor, and then into the base of a transistor but the output from the emitter was only the positive half of my triangular waveform, and I need the detector to oscillate with the positive and negative peaks.
I know that I could order an op amp ic that drives a higher current, but if possible I'd like to use parts that I have on hand.

I have a spice schematic attached for reference. Spice doesn't have the LM324 so I just used the LT1014 to draw up the schematic. I also attached the schematic with the added transistor.

enter image description here

enter image description here

Thanks in advance for any ideas!

Best Answer

Since you are already using an LM324 as a oscillator at 400 milliHz (0.4 Hz). Just use one of the addition 2 opamps in package as a buffer amplifier with a class B output stage.

schematic

Select Q1 and Q2 based on load requirements.

There will be small amount of crossover distortion as the load current requirements change sign. If that's an issue bias the output for class-AB.

Related Topic