5V 500mA Switching Circuit


Caution: I won‘t take any responsibility for any damage!

This is a circuit, which I found on 5V/2A switching with Wemos D1 mini without relay and which is able to switch 5V at 500mA (or more) with a microcontroller like the D1 mini or an ESP8266.

It should be able to handle more than 500mA, but I only tested it with nearly 500mA.

Required parts:

Optional parts:

This is the circuit setup:

Here is the Fritzing file for this circuit:


In this Fritzing circuit was a NodeMCU used, which can be found here: esp8266-fritzing-parts

The micro-USB-Port was used to provide the 5V/500mA. It also powers the NodeMCU. As load, a high power 3W (red) LED was used. Of course also other loads can be used. If a high power LED is used, it is important to use a resistor for the LED, which can handle the power needed. In this case: 3W

If the circuit needs to be compact, instead of the BC548C a IRLML2505 and instead of the IRF9510 a IRLML6402 can be used. Both parts are available as SMD.