I bought a set of these cheap Relay Power Switches on Amazon and I cannot figure out how the jumpers work on these units. See link and attached photo for more detail on my specific units.
I am using these with a ESP82666 NodeMCU MicroController and want to switch a 12v DC line for a CPU fan. I have read reviews and posts saying the an ESP8266 NodeMCU doesn't reliably provide enough current to power these reliably, so I was planning to power the relay via VCC & GND with a separate power supply so my MicroController doesn't have to power it. But there are not instructions with these units and the details on the Amazon page are weak.
1. Looking for an explanation on when to keep the jumpers connected or remove - and which jumpers for various cases.
2. If powering with a separate supply (like I intend) - should I target a specific voltage/current?
Any advice or help much appreciated, thanks.
I am using these with a ESP82666 NodeMCU MicroController and want to switch a 12v DC line for a CPU fan. I have read reviews and posts saying the an ESP8266 NodeMCU doesn't reliably provide enough current to power these reliably, so I was planning to power the relay via VCC & GND with a separate power supply so my MicroController doesn't have to power it. But there are not instructions with these units and the details on the Amazon page are weak.
1. Looking for an explanation on when to keep the jumpers connected or remove - and which jumpers for various cases.
2. If powering with a separate supply (like I intend) - should I target a specific voltage/current?
Any advice or help much appreciated, thanks.