Free electronic circuit design and schematic diagram
This schematic diagram shows a ring-around LED flasher circuit. This circuit will turn off two LEDs and turn on the other two until the timing cycle reverses. This circuit can be configured to flash four LEDs in sequential order by pressing and holding S1 closed until only one of the LEDs is on then releasing it. Here is the schematic […]
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In the relay’s point of view, dark activated means the relay will be activated when the light intensity fall below a certain threshold. Without hysteresis, the relay will be activated and deactivated if the sensed brightness fall under or rise above a single point of darkness level. With hysteresis, the darkness level for activating and deactivating the relay will be […]
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This circuit gives a changing-color LED display, where a LED will emit a dynamic shifting color, from red to green smoothly through yellow. The circuit uses NE556 dual timer, equal to two 555 IC but in only one package. The oscillators is set at different frequencies. The high frequency (upper part) is used to construct a PWM signal, and the […]
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This is a audio-controlled lamp circuit. This circuit requires low voltage input such as pre-amplifiers, tone control, or general audio line level output. It’s also possible to feed the input with signal from small power amplifier output, or high power amplifier witk low volume level. The characteristic of lamp dimming (incandescent lamp) will look like coming from proportional controller since […]
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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 makes use of a remarkable […]
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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 you can use other transistor […]
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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 constant-ripple LED driver fixes the […]
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