Newbie needs help for pHat: Wiring diagram for consumer at output


#1

Hi,

I’m a newbie.

I do not understand how to connect a 24V consumer at the output terminal of the automation pHat.
Is there any example wiring diagram? I know that I need an external 24V power supply.

Many thanks.


#2

Need more detailed info on what exactly your trying to do? Its not clear to me what your asking?

What input or out on the automation pHat are you wanting to use, and what are you connecting to it?


#3

Hi,

thank you for your reply.

I want to switch-on and switch-off a small current through a temperature sensor PT1000 (and an additional resistor) via the output pins. Via the ADC I want to measure the voltage at the sensor in the moment the current is switched-on.

Question is: How to connect a 24V power supply and the sensor to the output pins.
I think the ground of the power supply has to be wired to the ground of the pHat. The plus of the power supply to the resistor. The resistor to the sensor. The sensor to the ground. Is that correct?

Regards.


#4

If I have correctly understood what you plan?
One way to do it is to feed your +24V to the C terminal of the relay.
Then feed the NO contact of the relay to your temp sensor > resistor > ground.
Turning the relay on will feed the +24v to the temp sensor > resistor.
Then connect the ADC pin to the temp sensor resistor junction. Where the two are connected together.