Free Simple Circuit Diagram
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 can control the PWM waveform. […]
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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 and 0.05uA when disabled. The […]
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This is infrared (IR) proximity detector circuit. A matched infrared emitter and detector pair is used in this circuit. The voltage controlled oscillator section of the LM567 tone detector IC is used to set the emitter LED pulses at frequency. In this circuit, the center frequency of the VCO is set to about 909 Hz by combination of capacitor C1 […]
Read moreA 40 watt fluorescent tube lamp or two 20-watt tubes in series will be driven by this circuit but this circuit will produce less brightness than usual, since this circuit only deliver 6-12 Watts. This circuit draws 0.9-1.2 Amps for 2 x 20 watt tubes, or 0.45-0.9A for 1 x 20 watt tube, depending on the potentiometer setting. Here is […]
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