OPTO-THERMO CONTROL RELAY SWITCH
1. ABSTRACT:
Ø The circuit shows the working of opto-control switch, where LDR is
used as a switch to open and close the circuit.
Ø 555 timer IC is used as a comparator.
Ø The product of RC is used to produce the delay in the IC and
affects pulse propagation through it.
2. COMPONENTS:
Ø Resistors (1k,47k,10k)
Ø Capacitors (2*.01uF, 1*4.7uF)
Ø IC LM555
Ø LDR (500 ohms)
Ø Speaker (8 ohms)
Ø Battery 9V
3. CIRCUIT DIAGRAM:
Ø In P-Spice:
4. OUTPUT RESPONSE:
Ø When Light is not falling on
LDR:
·
Voltage:-
· Current:-
Ø When Light is falling on LDR:
· Voltage:-
· Current:-
5. APPLICATIONS:
Ø Used in parking system. When the car comes near the gate of
garage, the parking lamp glows and the gate opens as the light falls on the LDR
and the current passes through the circuit.
Ø Security alarm
