I’m working on a small fist tank project using pi zero w + automation hat. I have planned all the control connection out. However since all my equipment are 12 or 24v dc power I worrying if it possible to cut all the individual wall plus and just use one big dc power supply and run everything in parallel connection. There are led light, pump, heater, etc so I’m not totally sure if i need to add any protection in the circuit or not. I read the automation hat have integrated circuit protection on board?
You don’t want to power a 12V load with 24V etc. If thats what your asking. You’d have to regulate the 24V down to 12v if you wanted to use the one 24 V power supply to run everything. And another step down to 5V if you also want to run the Pi from that one 24V power supply.
And your single 24V power supply would need to be able to supply the current required to drive the multiple loads.
Not really I’m asking if th relay/output on the hat have protect from current/load feed back. Or if there any interference you guy can forsee. The power supply will have power. Actually it have 30% more than total power of the system. 12v, 10v, and 5v equipment will have a buck step down. Actually for 5v power for Pi I dont mind using an alone wall plug prevent any unwanted interference back to the main board.
The contacts on the relays are for all intents and purposes isolated from everything else. Its just a mechanical switch pulled magnetically by the relay coil. The coil itself will have back emf protection to kill the pulse produced when the coils magnetic field collapses.
I would think, as long as you don’t exceed that max voltage and or current rating of the relays, it should be fine. No more than 24V and no more than 2A per relay. You may want to put some 2A fuses in your power feeds if thats what your worried about.
Got it thank I was mainly to see if I need to add any flyback diode to the circuit.
Going over your diagram one more time, you may need one on the relay you added. I do believe the automation hat output can handle it but It can’t hurt to add one anyway. The polarity of the back EMF pulse will be opposite to the polarity used to operate the relay.