Min Maestro 12 servos go crazy

Hi,

I read the other threads and am still not clear. I hooked a 12VDC5A power supply to my Maestro by cutting the wires and splicing a servo cable to it (black to red for the wires. I ignored the control wire on the servo cable because I was just using the power). When I hook it all up - maestro to computer via USB and power supply and servo the servos go crazy and vibrate. I burnt a few out. The only thing I can think is that I didn’t use the blue shorting block. I am unable to because the servo connector is in the way.

Thanks




I just noticed that in the pics the power plug is on backwards to the board. That is not how I ran it, i just plugged it in for pictures and unplugged it. So that’s not the problem.

Thanks

Hello. Please see the “Powering the Maestro” section of the Maestro User’s Guide. It is unlikely that your servos can tolerate 12 V so you probably need to find a more appropriate power supply for your servos (around 5V).

–David

Typical servos run at 4.8V, and may be 6V tolerant. High-voltage servos run on 7.4V and may be 8.4V tolerant. 12V is way too much.

Pololu sells a nice 7 amp buck converter that can take your 12V down to a better voltage for the servos with good efficiency. You can also use a high-current linear voltage regulator, but that will burn a lot of excess power in heat, which is very inefficient (and gets very warm.)

Another option is to get a “UBEC” from an RC supply store. However, most UBECs I’ve used are pretty shoddy quality – one even blew up in my face with a bright flash! I’d much rather trust the Pololu circuits.

Thanks for the replies. Any chance you can tell me what converter to buy? Sorry this is all out of my experience. I am trying to learn.

Thanks

Oh and I did read the user manual, a lot! And this is what I based my power choice on…

“Board can be powered off of USB or a 5 – 16 V battery, and it makes the regulated 5V available to the user.”

Regulated 5 volts…