Schematic Diagrams

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

led circuit

Manual Adjustable LED Driver

In many electronics-level adjustments such as LED drivers for LCD panel backlight controls, we can use AD5228. A manually adjustable LED driver is shown on figure below. The voltage across the white LED D1 is set by the AD5228 for the brightness control. A typical white LED with Vf of 3.5 V requires a resistor, […]

LED Driver: 6 Channels with Phase Shift Control

We can use ISL97676 as a LED driver that drives 6 channels of LED current for TFT-Display. The ISL97676 is used to drive 6 channels of LED to support 78 LEDs from 4.5V to 26V or 48 LEDs from a boost supply of 2.7V to 26V and a separate 5V bias supply on the ISL97676 […]

Single Cell LED Flashlight

This is Single Cell LED Flashlight circuit. This circuit uses white LED that has best power-efficiency combination at about 20mA and requires abut 3.3V. Each Led in this circuit draws power about 66mW. This circuit uses seven LEDs. This circuit very useful for a tiny pocket flashlight because the whole array of leds run at […]

Touch Sensitive LED

Below is the simplest circuit you can get. We can use any NPN. Connect the 220 ohm resistor, LED and transistor as shown in the figure below. Touch the top point with two fingers of one hand and the lower point with fingers of the other hand nad squeeze. When you squeeze harder, the LED […]

Animated LED for Bike Turning Signal

Using circuit below, we can animate the bike turning signal using LED. The bike turning signal will blink from the right side (D1) to the left side (D5) in a bar style. To build a complete left and right turning signal, you must build two units of this circuit, and arrange the LEDs so the […]

Blinking LED Emulates Incandescent Bulb

This is flashing LED circuit emulate the turning of incandescent lamp.  The characteristic of incandescent lamp is that they can’t abruptly change the luminosity. This circuit is used to fade in and fade out the on and off state change.   Here is the schematic diagram of the circuit: The time constant of this fading is […]


Sound Controlled Activated Triggered LED

When the microphone detects a loud sound, this circuit will turn the LED on. The “charge-pump” section consists of the 100n, 10k, signal diode and 10 uF electrolytic.   Here is the schematic diagram of the circuit: The charge pump section has two functions: rectifying and multiplying  the signal voltage. To illuminate the LED, a signal […]

Low-Dropout, Constant-Current Triple White LED Driver

In conventional white LED design, the Max1916 low-dropout bias supply for white LEDs is a high performance alternative to the simple ballast resistors. A single resistor is used by this device to set the bias current for three LEDs, which are matched to 0.3%. On enable condition, the MAX1916 consumes only 40uA of supply current […]

Brightness Control for Multiplexed LEDs

To add PWM intensity control to connected LEDs, a switched-LED power supply approach can also be used. A circuit using a PWM-based supply to provide additional intensity control to some LEDs is shown on figure below. The PWM waveform and I²C commands to the LED driver is sent from the same microcontroller. A software routine […]

AC-Powered LED

Usually, LED is powered by DC supply, but this circuit can make the LED can be powered by AC supply. This circuit can be used as power indicator for Water pump. There are two circuit  versions of AC-powered LED presented here. First is circuit for US or Canadian 110-120V 60Hz AC lines and European or […]

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