Hey everyone, I'm not very experienced with electronics but I'm helping my son with his project. He wants a simple setup where pressing a button turns on a small continuous servo motor, and it should keep running until another button is pressed to turn it off. I've read that we might need a flip-flop circuit for this, where the first button closes the circuit for the servo, and the second button opens it again. The catch is that he doesn't want to use an Arduino or anything complex, just straightforward controls. Any ideas on how to build this flip-flop circuit or if there's an easier part we could use?
3 Answers
Consider using latching SPDT buttons like you would for 3-way light switches. Alternatively, a relay could work too! There are also modules available specifically for this purpose, but make sure you know your servo model and application.
You’ve got the right idea with the flip-flop circuit! You can make one using NOR or NAND gates. Basically, connect the "on" button to set the flip-flop, and the "off" button will reset it. Just keep in mind that your servo needs a voltage and current higher than what TTL logic can provide, so you may want to include a buffer stage if that's the case.
A latching relay could be the perfect solution here! It's simple, and you'll both learn how it works while building it. Just make sure to hook it up with a couple of momentary switches as needed. You can find a bunch online that might fit your needs.
Definitely go for the relay! I think it will work out great for what you're trying to do.
You could also just use a 7475 chip; it's a more straightforward way to handle the flip-flop functionality.