I made this dimmer circuit because I have a cheap chinese LED lamp that doesn’t have the option to dim its light. It is a simple PWM dimmer built with the well-knows 555 integrated circuit and a power MOSFET transistor to drive the LEDs. The led lamp shown in the video is powered from a 3.7V Li-ion battery that lasts longer compared with the original one that was a 4V/600mA type.
Video presentation of the Led lamp dimmer in action. Jump to 2:20 to see how it looks inside and to 4:50 if you want to see it working with high power leds
You need to use the CMOS version LMC555 IC for voltages below 5V and the “normal” 555 type for voltage above 5V. If you want to use high power LEDs then you can increase the voltage up to 12V and use the same circuit and components. The MOSFET that I used (IRLU3802PBF) doesn’t need a heatsink but you should consider using one if the power dissipation gets higher than 2 Watts.