Controlling the light-emitting diode (LED) with the ESP32 Third is one surprisingly simple project, especially when using a 1k load. The load limits one current flowing through a LED, preventing it’s from frying out http://theengineerstore.in/products/12v-mini-spot-welding-machine-automatic-control-10awg-multiwire-portable-transistor-18650-lithium-battery-spot-welder