This is a very simple LED dimmer circuit which has 2 transistors, 1 resistor and 2 potentiometers. Typical segment displays LEDs consume around 25 mA for each segment and should be limited to this ...
Most commercial LED flashlightsuse three AAA or AA batteriesin series that produce 4.5V. The batteriesthen drive four white LEDs that connectin parallel. These LEDs can workat voltages as low as 2.7V ...