This is another super-simple Weekend Projects circuit design but I admit the four-amps-in-one aspect of the LM324 might seem confusing at first. This Texas Instrument data sheet [PDF] on the LM324 might help clarify some questions. On the first page, you can see the pin orientation. Each op-amp is numbered counter-clockwise starting from the top-left of the IC. So op-amp #1 is 1OUT, 1IN-, and 1IN+, and so forth for each op-amp. As noted. we’re only using two amps in this circuit, or pins 1-3 and 5-7. Pins 4 & 11 are also used as our IC’s power pins, operating as the common-collector voltage and GND, respectively.
If you have any further questions about this circuit design you can always feel free to email us. And of course all these tips & tricks, pointers and other makers’ builds are highlighted in our Weekend Projects Newsletter, so if you’re not already subscribed, sign up below!
Sign Up for the “Weekend Projects” Newsletter
See all of the RadioShack Weekend Projects posts (to date)