I've sure you've seen those persistence of vision displays where a spinning arm has some LEDs on it, and they light at the correct time to create the appearance of a static image. I'm looking to do something like that. But I want to make something sturdy and professional looking. Whenever I've seen someone transmit power to a shaft they do something homebrew like stick plates of copper on the shaft and rest another strip of copper on it. What I want to know is is there something specifically designed for this purpouse? Something which will be better than having a long shaft with a bunch of copper fingers on it, if I wish to keep the micrcontroller in the base rather than on the arm itself?
It probably needs to be something I can just slip onto the shaft. I thought about using a telephone cord detangler but that would have to function as the shaft itself and wouldn't be very robust. I've also considered TRS connectors like those used on headphones. Those are designed to freely rotate. I'm not sure how sturdy they would be though if used as a shaft. I'm afraid of the contacts inside wearing out quickly.
They are called slip rings and can be expensive, they are just like the ones you would make only more sturdy. Because there is mechanical contact they will eventually wear out.
Put a coil on the PCB that the shaft passes through and then wire in a rectifier, capacitor and 5v regulator. The coil will now spin with the shaft and the PCB.
Then mount a coil round, but not touching, the shaft. This coil does not spin and could be attached to the body of the motor.
Pass an AC current through the static coil and it will induce a current in the spinning coil attached to the PCB if they are close enough. A high frequency will work better than 50Hz of the mains, just like the high frequency in a switched mode power supply
Grumpy_Mike:
They are called slip rings and can be expensive, they are just like the ones you would make only more sturdy. Because there is mechanical contact they will eventually wear out. Slip ring - Wikipedia