Lantern Dimmer/Flasher Circuit Diagram Analysis

Here is the circuit diagram for the lantern dimmer/flasher designed by Tony Van Roon:

There are two circuit modes: dimming and flashing. Flashing mode is useful for warning other drivers of your trouble, and it can be adjusted to have a very short flash duration for long-term use, such as when the car must be left on the shoulder overnight.

Electronic parts list:

Lantern Dimmer Circuit Notes:

The S1 switch is used to activate the "blinking" mode.

P1 is the dimming potentiometer, you can adjust the dimming setting from here.

Transistor 2N4401 can be replaced by NTE123AP, BC547.

The transistor TIP32 can be replaced by NTE197. Other transistor types may work.

The DC power source or battery for this lantern dimmer/strobe is 6-12V.

There is nothing particularly important about the resistor and capacitor values, and the experimenter can change them if desired. For example, a 10K pot could be replaced with a 5K by also increasing the 3.9K resistor by 2 (8.2K would work as well). The 100K in the flash circuit could be a different value if the capacitors were also scaled (conversely, 0.1 and 10uF would be halved if the resistors were doubled).