Lantern Dimmer and Flasher

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

There are two circuit modes: dimming and flashing. The flasher mode is useful for warning other drivers of your troubles and it may be adjusted to have a very short flash duration for long-term use as when the car must be left on the shoulder over night.

Electronic Parts List:

Lantern Dimmer Circuit Notes:

• S1 switch is used to activate the ‘Flashing’ mode.
• P1 is the dimmer potentiometer, you can adjust the dimming setting from here.
• Transistor 2N4401 can be substituted with a NTE123AP, the BC547.
• Transistor TIP32 can be substituted with a NTE197. Other transistor types might be work.
• The DC power supply or battery for this lantern dimmer / flasher is 6-12V.

There is nothing particularly critical about the resistor and capacitor values and the experimenter may change them, if desired. For example, a 10K-pot may be substituted for the 5K by increasing the 3.9K resistors by 2 also (8.2K would be fine). The 100K’s in the flash circuit may be a different value if the capacitors are also scaled (inversely–if the resistors are doubled, the 0.1 and 10uF are halved).

Good luck…