Light detector circuit using transistors and relay

Light detector circuit using transistors and relay

This light detector circuit activates a lighting device through a relay when the intensity of the daylight is no longer sufficient.

It can be used to illuminate the main entrance of the house, a showcase that must be kept lit at night, an unsafe area at night, etc.

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Temperature alarm circuit with Op. Amp.

Temperature alarm circuit with Op. Amp.

Temperature alarm circuit with 741 operational amplifier

This temperature alarm circuit with operational amplifier activates a relay when the temperature of the place to be controlled exceeds a set level. Useful for an oven temperature control or a cooling system

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Twilight switch circuit with operational amplifier and LDR

Twilight switch circuit with operational amplifier and LDR

This Twilight switch circuit activates a light, a lamp, a motor, etc., at the time of sunset and performs the reverse process at dawn.

This is an ideal circuit for activating a security light that must be on all night.

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Dark detector circuit using LDR and relay

Dark detector circuit using LDR and relay

Dark detector circuit using LDR and relay

This circuit uses, as a main component, an LDR (photoresistor). An LDR changes its resistance value depending on the amount of light it received.

The more light means less resistance, the less light means more resistance.

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Water Level Controller Circuit

Water Level Controller Circuit

Water Level Controller Circuit This simple Water level controller circuit is useful to control the water level in a tank. It does this by turning On and Off a water pump depending on the status of the sensors. With a NC (Normally Closed) or a NO (Normally Open) contacts of the relay RL, we can handle any type of starter. […]

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