Archive for category: Lighting Circuits Diagram

Temperature controlled DC fan by BD140

Lighting Circuits Diagram | By: Diagram mania

Here is a simple circuit based on two transistors that can be used to control the speed of a 12 V DC fan depending on the temperature.A thermistor (R1) is used to sense the temperature. When the temperature increases the base current of Q1 (BC 547) increases which in turn decreases the collector voltage of […]

Dark Activated Terrace Lamp

Lighting Circuits Diagram | By: Diagram mania

Compact circuit, Can be wired in parallel to existing switches This device allows one or more lamps to illuminate at sunset and turn off at dawn.Q1 and Q2 form a trigger device for the SCR, providing short pulses at 100Hz frequency. Pulse duration is set by R2 and C1.When the light hits R1, the photo […]

Dark Activated Led or Lamp Flasher

Lighting Circuits Diagram | By: Diagram mania

Simple photo-sensitive circuit, 3V battery supply This circuit adopts the rather unusual Bowes/White emitter coupled multivibrator circuit. The oscillation frequency is about 1Hz and is set by C1 value. The LED starts flashing when the photo resistor is scarcely illuminated. The onset of flashing can be set by trimming R2. Parts: R1 = LDR R2 […]

220Vac Lamp Toggle Switch

Lighting Circuits Diagram | By: Diagram mania

Compact, transformerless circuitry No relays employed Due to the low current drawing, the circuit can be supplied from 230Vac mains without a transformer. Supply voltage is reduced to 12Vdc by means of C1 reactance, a two diode rectifier cell D1 & D2 and Zener diode D3. IC1A, IC1B, R2, R3 and C3 form a reliable […]

12V Speed Controller and Halogen lamps Dimmer

Lighting Circuits Diagram | By: Diagram mania

This handy circuit can be used as a speed controller for a 12V motor rated up to 5A (continuous) or as a dimmer for a 12V halogen or standard incandescent lamp rated up to 50W. It varies the power to the load (motor or lamp) using pulse width modulation (PWM) at a pulse frequency of […]

Sound-Activated Lamp (Relay-Switch)

Lighting Circuits Diagram | By: Diagram mania

This simple circuit shown int the schematic diagram actives the switch using sound. We can use this circuit for various applications, such as automatic (sound-controlled) disco light or car’s LED light show.  The Q1 amplify the audio from mic. The R1 is used to adjust the peak of signal to greater than about 0.7 volts, […]

9 Second LED Timer and Relay Circuit

Lighting Circuits Diagram | By: Diagram mania

This circuit provides a visual 9 second delay using 10 LEDs before closing a 12 volt relay. When the reset switch is closed, the 4017 decade counter will be reset to the 0 count which illuminates the LED driven from pin 3. The 555 timer output at pin 3 will be high and the voltage […]

LEDs Temperature Indicator circuit diagram

Lighting Circuits Diagram | By: Diagram mania

This circuit is a circuit which will provide output indicator of the temperature around the circuit. The indicator is just 2 pieces LEDs (D1 and D2) which indicates the heat of above 80 degrees Celsius and below 80 degrees Celsius. A well-known IC LM35 is chosen to be the temperature sensor in this circuit. Output […]

Light / Dark Relay Switch

Lighting Circuits Diagram | By: Diagram mania

  Light / Dark Relay Switch   A simple light / dark activated relay switch circuit, suitable for many applications like the automatic switching of the lights in a shop window or a room according to the ambient light level. The circuit uses a light dependent resistor (LDR). A light/dark option has been incorporated. The […]

Dome Light Dimmer With Delay For Cars

Lighting Circuits Diagram | By: Diagram mania

  Dome Light Dimmer With Delay For Cars   There are two stages: aboriginal one is dabbling and the additional one is fading. Back you accessible the aperture the ablaze turns on. You get central and abutting the door, but the ablaze stays on (delay stage) for an adjustable aeon of time (0-40 sec. for […]