RC Switch with Medium Low-Side MOSFET

I’m using an INA219 DC Current Sensor Breakout (see attachment) to monitor the current used by the motor of a quadcopter. However, it will be possible to use the Pololu RC Switch with Medium Low-Side MOSFET (item #: 2803) to turn the motor On/Off via the RC receiver?

pololu.com/product/2803


Hello.

It is unclear to me where you want to use our RC Switch in your system. It looks like you have a brushless DC motor and an ESC for that motor in your diagram. Brushless DC motors like that require a very specific sequence of power switching on their 3 input wires to run, so our RC switches would not be a suitable substitute for the ESC. You might be able to turn power to the ESC off with our RC switch, however I am not sure why you would want to do that since I expect the ESC would draw very little power compared to the motor itself and the ESC should be capable of remotely turning off the motor.

If you are planning on using that RC switch to turn the ESC on and off, you should be aware that the switch works by opening the circuit on the ground side of the connection and the ESC might share that ground on the 3 pin signal connector, so you might need to disconnect that ground as well.

-Nathan

Hi Nathan,

We are not looking for the RC switch to substitute the ESC controlling the brushless motor. Instead, we need to simulate a motor failure while the vehicle is in the air so when need the RC switch to power off the motor/ESC. Sorry, I was vague when I asked my original question.

Can we connect then RC Switch to the RC receiver and between the battery and the ESC to power off the motor?

Thanks again!

I think you might be able to use the switch like that. Just be aware that you might need to disconnect the ground on the 3 pin servo signal connector. Also, I do not know how disconnecting that ground would affect the ESC reading the signal from its controller, though I used a similar circuit to turn off a different ESC on one of my robots. If the extra size is not a concern, using the relay version of this switch on the positive lead to the ESC might be more reliable.

-Nathan

We cannot use the relay version because space and weight are a constraint. Do you have a diagram showing how you connected yours for your robot? Will the connection below work? Thanks Nathan!