Hi,
What is the maximum PCB current tolerance? We are planning to control many brushless servos with pololi, and current may average in the 10’s upwards of 50 amps. The bus line for + and - power supply looks like it should be able to handle at least a solid 15-20 amps. Does anyone know for sure?
Hello.
Could you tell me what product you are using; ex:Arduino, Micro Maestro, Mini Maestro, etc. Are you using brushless motors, or RC servos that use brushless motors internally? If you are using a Maestro servo controller, I recommend running your servo power and ground connections externally to the board with properly sized wires.
-Ken
Hmm, I’m not sure what you mean by externally. Do you mean to have only the signal pin connected, and create a new interface just for power?
We are using an 18 and/or 24 mini maestro servo controller. The servos are going to be futuba brushless. I did not find any alternatives (they claim to be the first). Have you heard of other brushless servos? Not only brushless, but they are also waterproof and metal-gear with dual ballbearings. Under $100.
Do you know for sure the maestro can’t handle the amperage? It’s only passing through to the servo wires (not going into any of the microcontrollers).
Yes, I mean you can supply the signal from the Maestro and not use the servo power connection, but you will still need a reference ground connection between your power connections and the board. The board’s power traces should be able to handle 15-20A okay. Keep in mind that the header pins are only rated at about 3A and the terminal block on the bigger Maestros is only rated for 10A. You could try to run the power through the board’s power traces. However, you should monitor the temperature to make sure you do not melt anything.
-Ken
Hello.
Here is a wiring diagram that hopefully makes it clear how you should be wiring servo power external to the Maestro:
- Ryan
Very helpful, thanks. So you agree with Ken that somewhere in the 10A-20A range will necessitate off-PCB power lines?
I think if you are using a lot of current you should be careful and monitor it. Typical servos draw about 1A per channel. The more you deviate from that, the more you want to consider where your current is going and if it is heating things up. For the situation you initially described–currents sometimes approaching 50 A–, I recommend using off-board wiring like my wiring diagram.
- Ryan
