Tag Archives: led circuit

Resonant Mode LED Driver

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This is Resonant Mode LED Driver circuit. This circuit is used to give a constant DC current through a string of a given number of LEDs. This circuit uses flyback, boost, or buck topology. Each of them has disadvantages and advantages depending on the number of LEDs being driven in… Read more »

Backlight Driver for WLED-Display

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This is WLED-display backlight driver circuit. This circuit can be used to power WLEDs by replacing the voltage-feedback network with a series current-sense resistor, R3, and the WLED strings. This circuit uses The TPS6108x that drive some series WLEDs in parallel for backlighting larger displays. Here is the circuit: The… Read more »

White LEDs Mains Night Light

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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.

Random Blinking (Flashing) LED

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We can using this circuit to make the LEDs blink in a random pattern according to the slight differences in the three Schmitt Trigger oscillators. The CD4511 is BCD to 7 segment Driver, so the pattern of the led is actually the come from seven segment representation. Arrange the LEDs… Read more »

Powering LED from Single AA Cell

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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… Read more »