Simple ways to circuit bend a toy

Step 2 Opening the circuit and finding the bends

Now that you've got your toy, get out your screwdriver and open the thing up. Be careful to keep track of all of the screws! A digital camera is also really helpful--take pictures at various steps in the process, like before removing something major, so that you can retrace your steps backward if necessary.

The best suggestion I can give is to simply experiment: play around with different values of resistors, different connections in the circuit, with capacitors, diodes or inductors, with putting yourself in place of a resistor, etc. A good place to start is to just connect different points in the circuit together with wire and see what happens. And if you end up causing all sound to cease, you might have crashed the processor; just remove the batteries (to reboot the processor) and try again.

Finding the places on the circuit that give you interesting sounds is the black art of circuit bending. There are a few things that can be helpful:

• On basic toys like this, it's usually pretty easy to find the resistor that controls the pitch. Often it's near one of the ends of the chip (like it is in this toy) and can be distinguished from other resistors that are near other components (like those near transistors that control audio outputs). Look at the image of the board to see where the resistor is in this particular circuit, and then look for an analogous place in your own circuit.
• Power and ground can be easy to find--look first for where the leads from the battery hit the circuit board. Often this will also be the place on the board where the traces are the thickest (widest). You'll connect things to ground to create "voltage dividers" that enable you to change things like pitch.

So many different, strange, and unexpected things can happen when you just play around. But once you've found something cool, and that you can reproduce, be sure to make note of it so that you can return to it when you start to make things permanent.

Comments

[adebruin]

Thanks for all these beginner bend tips. I started to play with connections on a keyboard's circuit board (my first attempt at circuit bending). Found a few intersting sounds, made some notes but didn't solder any points. But I hit some contacts that killed the sound. And taking out the batteries doesn't reset the circuit board, but the keyboard is definitely powering off and on still. Just no sound. Any suggestions?! Thanks!