Inverters - UPS Circuit DiagramsIR devicesLCD-LED DisplaySimple Circuits

SIMPLE LDR CONTROL CIRCUIT

Light dependent resistor (LDR) LDRs (light-dependent resistors) are used to detect light levels, for example, in automatic security lights. Their resistance decreases as the light intensity increases: in the dark and at low light levels, the resistance of an LDR is high and little current can flow through it.

The LDR. LDRs (light-dependent resistors) are used to detect light levels, eg in automatic security lights. Their resistance decreases as the light intensity increases. In the dark and at low light levels, the resistance of an LDR is high, and little current can flow through it. High sensitivity (due to the large area it can cover). Easy employment. Low cost. There is no union potential.

Using an LDR and a few components, this is a very basic circuit for turning on a light in the dark. The sensor is an LDR, and the electronic switch is a transistor.

 

 

Simple LDR CircuitWorking:

The resistance of the LDR changes when light falls on its surface. The less light there is, the less resistance there is. A potential divider circuit is created by connecting resistance R1 (100K) and LDR in series. The intensity of the light affects the divided voltage. Because the LDR is linked to the Ground, the voltage loss increases as the light intensity rises. It is sensitive to a wide range of light.

An NPN Transistor BC147/BC548 is fed from the Potential Divider’s center point. As the base voltage of this general purpose NPN silicon transistor is around 0.5V or higher when compared to the emitter voltage, the circuit is completed, and the LED illuminates in the dark.

Parts Used:

  • LDR
  • Resistance of 100K
  • BC548 is a transistor.
  • LED

This Magic Eye circuit is both inexpensive and simple to construct. It will only cost you about 20 cents (Rs 15).

Automatic street lights, Electronic Letter Boxes, Electronic Eyes, Automatic Vehicle Headlights, and Automatic Garden Lights may all be made with this LDR circuit.

According to the spectral characteristics of LDRs, there are three types of LDRs: – Ultraviolet LDR: more active to ultraviolet light, including cadmium sulfide, cadmium selenide LDR, etc., used for UV exploration. – Infrared LDR: Lead sulfide, lead telluride and lead selenide are the main ones.
Tags

Related Articles

Leave a Reply

Your email address will not be published.

Back to top button
Close
Close