# How to use an Arduino to turn a supply voltage to another device on and off?

The Question: With what kind of extra components if needed, can I use to output a signal out of one of the Arduino pins to turn the voltage on and off to a device. The goal is to output a HIGH or LOW on a certain OUTPUT PIN to turn this device on and off.

The Limitations: I can't power this device with a pin from Arduino directly(I think..). Trying to find a simple solution, I don't have access to too many intricate parts, other than a NAND gate and a bunch of resistors and capacitors.

The Solutions??: I can get my hands on some additional components such as relays or if there is some sort of a voltage control switch with a transistor I can be setting up here to turn a 5 Volt supply on an off, if the max current I can deliver from my arduino pin is 40 mA, how would I go about setting up that circuit if thats a possible solution? Help much appreciated!

extra details: https://www.walmart.ca/en/ip/laser-x-2-player-blasters/6000196696362 The device I am trying to turn on and off, if a certain OUTPUT pin on my Arduino is set to LOW.

• use a mosfet to switch DC. a low-side switch using a logic-level n-chan is the simplest. google "mosfet switch circuit" for plans Feb 6, 2018 at 0:50
• what do you mean by turn this device on and off? Feb 6, 2018 at 1:35
• I mean to allow current through a wire and not allow it. Feb 6, 2018 at 1:40
• Would this be okay, I have a VCC from 3, 1.5V batteries for a nand gate, and I am feeding in the input from a Pin on arduino, if the arduino pin is HIGH I need the output to 0 Volt and if its LOW i need the output to be 5 Volts, and also to be able to draw sufficient current from the 5 Volts( technically 4.5V xD). Feb 6, 2018 at 1:45
• if in doubt, use a relay, they are universal (hi/lo side, ac/dc, whatever) Feb 6, 2018 at 3:57