Pololu Isolated Solid State Relay SPST 60V 7A - Optocoupler SSR reflectance sensor they do all of the

they do all of the resisting for you

High efficiency: typically 85%–95% depending on VIN

Plug type: Micro USB

We also toss in some header so you can solder it in and plug into a solderless breadboard

Pololu Isolated Solid State Relay SPST 60V 7A - Optocoupler SSR reflectance sensor they do all of theSmart Power Control with Pololu Isolated Solid State Relay Switch, SPST, 60V, 7A The Pololu Isolated Solid State Relay Switch, SPST, 60V, 7A gives you electronic power control in a smaller and cleaner package than a bulky mechanical switch. It is useful for battery powered devices, robots, portable test gear, and projects that need soft on off behavior or reverse voltage protection. Why you'll love it Optically isolated control: an opto isolated