The Equipment needed is :
1. Old Car Charger
3. Relay Button
4. Adapter 2,5 mm
Step 1: Open Car Charger
First Thing that you must open the car charger.. and cut the cable to small board, I used different picture of car charger to make it, cause i bought it just for almost 10.000 Rupiah (1 USD) for 4 Item.
Step 2: Solder the Cable
Step 3: Put the relay into casing
Ooohhh.. sorry for ugly nails... do not fokus on it...