Category «Lighting»

PWM RGB Controller

The design of a Pulse Width Modulated Red-Green-Blue controller will be explained here. This design is efficient because this design uses multiple strings of six LEDs with a 24V DC source. This design is sufficient for a sizeable light because a total current of 2 Amps will supply 600 LEDs per color. The circuit below …

Two Transistors Single Cell Battery LED Driver

To operate, LED needs more than 1.5V voltage level. If you want to operate a LED with a single cell battery, you must boost the voltage to enable powering the LED. Here you can use two transistor circuit for boosting the battery’s voltage: The transistor shown in the schematic diagram is 2N3904 and 2N3906, but …

LM3404 Constant Ripple LED Driver

To take an input voltage of 24VDC ±10% and drive 1A through as many LEDs in series as the maximum output will allow, the circuit shown in the schematic diagram below uses the ONO-based constant ripple concept. The average current controls the luminous flux and dominant wavelength (or color temperature for white LEDs). Because the …

Powering LED from Single AA Cell

The benefit of LED is longer lifetime than incandescent lamp, and even higher efficiency in latest LED technology. LED is also very compact, but unfortunately it needs higher voltage to operate. A single cell battery (1.5v) or rechargeable  cell (1.2V) cannot be used to power LED directly. We have to use a DC-to-DC step-up converter …

Discrete Running (chasing) Flashing LEDs

This is Discrete Running LEDs circuit. This circuit gives a chasing pattern like the running LEDs display in video shops. Here is the schematic diagram of the circuit: When the power is applied to this circuit, all transistors will try to come on at the same time. However, some will get a different turn-on current …

White LEDs Mains Night Light

WARNING: Don’t touch the circuit when plugged to the mains supply, this will cause a lethal electrical shock since it’s not isolated from the mains supply. A column of 10 white LEDs is illuminated by this circuit. The flicker is prevented by 10u capacitor and reduced by 100R resistor.