Most thefts happen after midnight hours when people
enter the second phase of sleep called ‘paradoxical’ sleep.
Here is an energy-saving circuit that causes the thieves to abort the theft
attempt by lighting up the possible sites of intrusion (such as kitchen or
backyard of your house) at around 1:00 am.
It automatically resets in the morning.
For this you need:
1)-bridge rectifier
2)-transformer i.e voltage regulator
3)- IC (ic cd 4060)
4)-LDR
5)-LED & bulb
6)-Capacitor & resistance
7)- TRIAC
The circuit is fully automatic and uses a CMOS IC CD 4060 to get the
desired time delay. Light-dependent resistor LDR1 controls reset pin 12 of
IC1 for its automatic action. During day time, the low resistance
of LDR1 makes pin 12 of IC1 ‘high,’ so it doesn’t oscillate. After
sunset, the high resistance of LDR1 makes pin 12 of IC1 ‘low’ and it starts
oscillating, which is indicated by the flashing of LED2 connected to pin 7
of IC1. The values of oscillator components (resistors R1 and R2 and capacitor C4)
are chosen such that output pin 3 of IC1 goes ‘high’ after seven
hours, i.e., around 1 am. This high output drives triac 1 (BT136) through
LED1 and R3.
Bulb L1 connected between the phase line and M2 terminal of triac 1
turns on when the gate of triac 1 gets the trigger voltage from pin 3 of IC1.
It remains ‘on’ until pin 12 of IC1 becomes high again in the morning.
Capacitors C1 and C3 act as power reserves, so IC1 keeps oscillating even
if there is power interruption for a few seconds. Capacitor C2 keeps trigger
pin 12 of IC1 high during day time, so slight changes in light intensity
don’t affect the circuit. Using preset VR1 you can adjust the sensitivity of
LDR1.
Power supply to the circuit is derived from a step-down transformer
X1 (230V AC primary to 0-9V, 300mA secondary), rectified by a full-wave
rectifier comprising diodes D1 through D4 and filtered by capacitor C1.
Assemble the circuit on a general purpose PCB with adequate spacing
between the components. Sleeve the exposed leads of the components.
Using switch S1 you can turn on the lamp manually. Enclose the unit in a
plastic case and mount at a location that allows adequate
daylight.
Caution. Since the circuit uses 230V AC,
many of its points are at AC mains voltage. It
could give you lethal shock if you are not
careful. So if you don’t know much about working
with line voltages, do not attempt to construct
this circuit. EMP(Engineering mini project.blogspot.com)
will not be responsible for any kind of resulting loss or damage.
enter the second phase of sleep called ‘paradoxical’ sleep.
Here is an energy-saving circuit that causes the thieves to abort the theft
attempt by lighting up the possible sites of intrusion (such as kitchen or
backyard of your house) at around 1:00 am.
It automatically resets in the morning.
For this you need:
1)-bridge rectifier
2)-transformer i.e voltage regulator
3)- IC (ic cd 4060)
4)-LDR
5)-LED & bulb
6)-Capacitor & resistance
7)- TRIAC
The circuit is fully automatic and uses a CMOS IC CD 4060 to get the
desired time delay. Light-dependent resistor LDR1 controls reset pin 12 of
IC1 for its automatic action. During day time, the low resistance
of LDR1 makes pin 12 of IC1 ‘high,’ so it doesn’t oscillate. After
sunset, the high resistance of LDR1 makes pin 12 of IC1 ‘low’ and it starts
oscillating, which is indicated by the flashing of LED2 connected to pin 7
of IC1. The values of oscillator components (resistors R1 and R2 and capacitor C4)
are chosen such that output pin 3 of IC1 goes ‘high’ after seven
hours, i.e., around 1 am. This high output drives triac 1 (BT136) through
LED1 and R3.
Bulb L1 connected between the phase line and M2 terminal of triac 1
turns on when the gate of triac 1 gets the trigger voltage from pin 3 of IC1.
It remains ‘on’ until pin 12 of IC1 becomes high again in the morning.
Capacitors C1 and C3 act as power reserves, so IC1 keeps oscillating even
if there is power interruption for a few seconds. Capacitor C2 keeps trigger
pin 12 of IC1 high during day time, so slight changes in light intensity
don’t affect the circuit. Using preset VR1 you can adjust the sensitivity of
LDR1.
Power supply to the circuit is derived from a step-down transformer
X1 (230V AC primary to 0-9V, 300mA secondary), rectified by a full-wave
rectifier comprising diodes D1 through D4 and filtered by capacitor C1.
Assemble the circuit on a general purpose PCB with adequate spacing
between the components. Sleeve the exposed leads of the components.
Using switch S1 you can turn on the lamp manually. Enclose the unit in a
plastic case and mount at a location that allows adequate
daylight.
Caution. Since the circuit uses 230V AC,
many of its points are at AC mains voltage. It
could give you lethal shock if you are not
careful. So if you don’t know much about working
with line voltages, do not attempt to construct
this circuit. EMP(Engineering mini project.blogspot.com)
will not be responsible for any kind of resulting loss or damage.
how to lesser the time to turn the lamp on
ReplyDeleteThe reset input should be low (0V) for normal operation (counting 0-9). When high it resets the count to zero (Q0 high). This can be done manually with a switch between reset and +Vs and a 10k resistor between reset and 0V. Counting to less than 9 is achieved by connecting the relevant output (Q0-Q9) to reset, for example to count 0,1,2,3 connect Q4 to reset.
ReplyDeleteThe reset input should be low (0V) for normal operation (counting 0-9). When high it resets the count to zero (Q0 high). This can be done manually with a switch between reset and +Vs and a 10k resistor between reset and 0V. Counting to less than 9 is achieved by connecting the relevant output (Q0-Q9) to reset, for example to count 0,1,2,3 connect Q4 to reset.
ReplyDeletesir how to reset ic cd 4060 .. .because the our kit midnight security light will be automatically turn on if can be plug.
ReplyDelete