USB Step-up Boost Converter (5V to 9V/12V) Shipping:4-6 Days It takes at least 100mA

It takes at least 100mA of current to bridge the oxide layer that forms on the relay contacts

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The SparkFun IoT RedBoard is an ESP32 Development Board that includes everything but the kitchen sink

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USB Step-up Boost Converter (5V to 9V/12V) Shipping:4-6 Days It takes at least 100mAThis USB(input) to DC(output) boost converter can step up 5V to 9V 12V, with a switch for selecting voltage and a digital LED display for showing output voltage. The USB input can be connected to various mobile power supplies, which is more convenient to use, and can be widely used in industrial sensors, routers and optical modems.