01-02-2012, 04:53 PM
laser guided door opener
[attachment=17023]
IC CD 4001
Buffered Inputs and Outputs
Standard Symmetrical Output Characteristics
100% Tested for Maximum Quiescent Current at 20V.
Low power TTL
Noise Margin (Over Full Package Temperature Range):
1V at VDD = 5V
2V at VDD = 10V
2.5V at VDD = 15V
PIEZO BUZZER
.A buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical or piezoelectric.
.The piezo buzzer produces sound based on reverse of the piezoelectric effect. The generation of pressure variation or strain by the application of electric potential across a piezoelectric material is the underlying principle.
.The Red lead is connected to the Input and the Black lead is connected to Ground.
CIRCUIT DESCRIPTION
A laser diode (LED1) is used here as the light transmitter. Alternatively, you can use any available laser pointer. The combination of resistor R1 and diode D1 protects the laser diode from over-current flow. By varying muliturn trim pot VR1, you can adjust the sensitivity.(Note that ambient light reflections may slightly degrade the performance of this unit.) Initially, when the laser beam is falling on photo-transistor T1, it conducts to reverse-bias transistor T3 and the input to the first gate (N1) of IC1 (CD4001) is low. The high output at pin 3 of gate N1 forward biases the LED-driver transistor (T4) and the green standby LED (LED2) lights up continuously. The rest of the circuit remains in standby state. When someone interrupts the laser beam, photo-transistor T1 stops conducting and transistor T3 becomes forward-biased. This makes the output of gate N1 go low. Thus LED-driver transistor T4 becomes reverse-biased and LED2 stops glowing.
ADVANTAGES
.The laser costs low, better quality security (as it is only point to point) and very large bandwidth.
.It can be used as multi appliance control.
.It consumes low power thus it works on normal 12v battery.
.It has a separate circuit so it cannot be affected by an external interference.
[attachment=17023]
IC CD 4001
Buffered Inputs and Outputs
Standard Symmetrical Output Characteristics
100% Tested for Maximum Quiescent Current at 20V.
Low power TTL
Noise Margin (Over Full Package Temperature Range):
1V at VDD = 5V
2V at VDD = 10V
2.5V at VDD = 15V
PIEZO BUZZER
.A buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical or piezoelectric.
.The piezo buzzer produces sound based on reverse of the piezoelectric effect. The generation of pressure variation or strain by the application of electric potential across a piezoelectric material is the underlying principle.
.The Red lead is connected to the Input and the Black lead is connected to Ground.
CIRCUIT DESCRIPTION
A laser diode (LED1) is used here as the light transmitter. Alternatively, you can use any available laser pointer. The combination of resistor R1 and diode D1 protects the laser diode from over-current flow. By varying muliturn trim pot VR1, you can adjust the sensitivity.(Note that ambient light reflections may slightly degrade the performance of this unit.) Initially, when the laser beam is falling on photo-transistor T1, it conducts to reverse-bias transistor T3 and the input to the first gate (N1) of IC1 (CD4001) is low. The high output at pin 3 of gate N1 forward biases the LED-driver transistor (T4) and the green standby LED (LED2) lights up continuously. The rest of the circuit remains in standby state. When someone interrupts the laser beam, photo-transistor T1 stops conducting and transistor T3 becomes forward-biased. This makes the output of gate N1 go low. Thus LED-driver transistor T4 becomes reverse-biased and LED2 stops glowing.
ADVANTAGES
.The laser costs low, better quality security (as it is only point to point) and very large bandwidth.
.It can be used as multi appliance control.
.It consumes low power thus it works on normal 12v battery.
.It has a separate circuit so it cannot be affected by an external interference.
