I just started doing electrical engineering as a hobby.
I want to build a circuit where a Micro-controller controls 300 LEDs. Those LEDs can draw a lot of power, so I use a larger power supply, which is quite inefficient when idling (3Watt Standby). This matters because the LEDs won't be on all the time. I will implement some kind of sensor which fires when I want light (like a button, human detection IR sensor, Bluetooth, ... ) and my idea was to use a second, more efficient power supply, which can power the controller as well as all sensors, but has not enough power for the LEDs. As soon the sensor fires, the micro-controller will activate a relay to activate the large power supply.
I am not quite sure if it is safe to use this layout, however, because I heard that you should not connect 2 power supplies in series. The LEDs get a DATA signal from my Micro-controller (which is on the efficient PS) while the LED is on the large PS.
I made a quick draft. Keep it in mind that I am no expert, so I might have made some errors.
- Outlet: 230V 50Hz
- PowerSupply1: 5V 2A
- PowerSupply2: 5V 30A
- Micro-controller: ESP32
- LEDs: WS2812B
- Data1: 3.3V < 10mA
- Data2: 3.3V < 10mA
Edit1: I added a big blue wire connecting both grounds together like many suggested