Schematic Diagrams

Useful schematic and wiring diagrams. ✔ ✔ Enjoy electronic circuits, let your idea comes to hardware

led circuit

Resonant Mode LED Driver

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 series, the LED output current, […]

10-20V Regulated LED Lamp

Resistor and LM317L act as a current regulator set to 40 ma. Current will flow from the battery through one pair of LEDs, and then to the regulator, through the other pair of LEDs and finally back to the battery. Noise on the power supply lines filtered out by the capacitor. To make the current […]

Backlight Driver for WLED-Display

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 feedback of this circuit is […]

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.

Random Blinking (Flashing) LED

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 to be far from seven […]

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 […]


Eliminating LED Pop/Click Noise

Typical LED indicator consist of resistor (R2) and LED, connected in series with a switch.  When the switch is closing or opening, a glitch noise may occur at the supply line. To avoid this noise, R2 and C1 are added to the indicator circuit and value of R1 is adjusted. Very slightly delay is provided […]

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 […]

Efficient LED Driver Works with Single AA Cell

This driver circuit is not only boost the voltage to enable a single battery cell to power  two red LEDs or one white LED, but also regulate the current so the light will be constant until the battery runs out its power. The main component of this single cell LED driver is transistors and ferrite […]

Adjustable High Power LED Driver

A circuit that can drive three to four high power LEDs is shown on figure below. The ADP 1610 is an adjustable boost regulator. The voltage headroom and current for the LEDs is provided by this device. An average gain of 12 feedback network that servos the Rset voltage and the ADP1610 FB pin 1.2 […]

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