Basic Concepts Of Electricity

Here is simple simple circuit diagram for home security alarm system based on LDR (Light Dependent Resistor) like in figure 1 below. This circuit has been publishing by Jaseem Vp in Circuit Gallery site. In here we will show you again this circuit diagram and also global description.

Circuit Diagram

Figure 1. Simple Circuit Diagram Home Security Alarm System using LDR
(Source: Circuitsgallery)

Component Parts

1. Battery 6V
2. Resistors ¼ watt (150kΩ)
3. LDR (Light Depended Resistor)
4. Transistor BC547
5. 6V Buzzer

Description

Circuit diagram like in figure 1 above is Simple Circuit Diagram Home Security Alarm System using LDR. To implement this alarm system for home, you have to provide an optical path (with LASER beams) around your home. The LASER path is made possible with one LASER torch and 3 mirror arrangements which encloses the whole area. Please refer the project arrangement section below to make this optical (light) path. We have explained about home security system in detail with animation/ simulation.

How the circuit working?

1. This circuit is based on LDR (Light Depended Resistor), a variable resistor in which the resistance varies according to the light intensity falling on it.
2. The LDR and resistor R1 forms a potential divider network, which is the main part of our security alarm circuit.
3. We have already discussed about how transistor acts as a switch, the same principle is used here.
4. The voltage drop across the LDR is used to drive the transistor switch. When the voltage drop is above cut in voltage (0.6V), the transistor is turned ON.

Please read more about the working and other of Simple Circuit Diagram Home Security Alarm System using LDR using link below: