s cheap as DC to DC "buckers" are on eBay, it would be a shame to heat up everything when pulse width modulation could soothe the savage beam...
Here are the specs. Don't forget this is a REGULATOR. You adjust it to keep constant voltage, a bright beam, with engine on, or off.
Type: non-isolated step-down module (Buck)
Dimensions: 70mm x 39mm x 31mm
Input voltage :4.5-32V ( please don't exceed 32V)
Output voltage :0.8-30V (continuously adjustable)
Output current :0-12A (Max.)
Output power: 100W, 200W (enhance heat dissipation)
Operating frequency: 300KHz
Conversion efficiency: up to 95%
Operating temperature: -40 to +85 °c
Short circuit protection: Yes (please try not to short-circuit)
Overtemperature protection: Yes (automatically shutdown the output)
Input reverse polarity protection: Yes (can not be prolonged reverse)
Installation: terminals, needn't solder
IN+: input positive
IN- : input negative
OUT+: output positive
OUT-: output negative
Applications:
Voltage convert: 12 to 3.3V; 12V to 5V; 24 to 5V; 24V to 12V
DIY an adjustable voltage regulated power supply
24V Car Laptop power supply
Car LED power supply
Small power motor speed control
Power supply transformers
Industrial equipment buck
Batteries buck, and etc.