Introduction: Battery Powered Car Monitor
Car Monitors are a great choice when it comes to needing a small display for a project. But the problem is most of the time those projects are battery powered and Car monitors run on 12 Volts. Even though 12 Volt Batteries exist their big and heavy. So to solve this problem this method could be used.
2. Soldering Iron + Solder
3. 5 Volt Battery Source ( 4 AAs are 6 Volts but they worked for me )
4. Video Signal to Test ( It wont power on if no Video is plugged in )
Step 1: Look Inside
Take off the cover and look at the circuit board. Find Datasheets for any chips and locate the BUCK REGULATOR, these things convert the 12 Volts the screen takes into 5 volts that it actually runs on.
Step 2: DATASHEETS
Test schematics on Datasheets are very reliable when it comes to regulators cause most likely thats how its gonna be on the actual circuit board its being used on. To know where to solder after removing the chip look at the pin descriptions. Your gonna be soldering your battery source's positive wire on the pin the regulator outputs 5 Volts. Ground of your source goes to the monitor's ground.
Step 3: DESOLDER THE CHIP
Be careful not to rip up any PCB traces as can be seen in the pictures. Capacitors and Inductors are basically open circuits when it comes to DC but if you wanted to be extra safe it wouldnt hurt to remove them. I removed the feedback resistor cause that forms a voltage divider that went back into the chip cause thats how regulators keep a stable output. Not sure how big of a difference it makes but I wanted to be safe.
Step 4: IT WORKS
It should power on, make sure video is plugged into something cause these things wont do anything unless theres a video signal. Now it can be used on anything that runs on 5 Volts. NES/SNES Clones, Raspberry pi, Arduino.