This is PIR motion sensor circuit. The movement lasted only one. Did not reach the detection accuracy of Pyroelectric. As product of a Passive infrared detector PIR. It will detect the change of the infrared radiation emitted by people or animals in motion. And the dictates that run the sirens or devices as needed.
Principles of PIR.
People or animals in the heat radiation spread around. The exact amount is number one. When a motion or movement will cause temperature changes in that area. Thermal energy changes. This results in a heat radiation wave spread out. About 0.74 to 300 microns wavelength corresponding to the frequency of the Infra Red fit.
MPCC to the PIR.
The MPCC – IC to replace an amp circuits difficult. It also enhances the ability to detect the PIR. In this project, we use number KC778B. It is the function of Enlarge signal of PIR motion detectors provides are strong enough to drive out to other output devices. such as the sirens or lights.
There is also adds the ability. In detecting the movement. By defining to run only the dark or light. Can schedule starts. Such as when the power supply provides the circuit with a time delay, Enough to be detected from space. Which will how long, it is up to the user to customize.
The Complete circuits.
Figure 1 shows the complete circuits of the motion detector. Starting at IC1 (MPCC-IC) receiver that detects the number KC778B, PIR1 number from RE200B. Into the pin 7 and 8, with as VR1 sensitivity in the detection of PIR.
When PIR1 and IC1 can detect the movement. The LED1 flashes to the rhythm of the movement of people or animals. The output signal to drive external devices. The pin 16 can drive a triac, optocoupler, relay is low voltage In this project, the transistor Q2(BC547) to drive LED2 when it detects movement.
In addition a pin collector of Q2(BC547) can be directly connected to the relay and 9-12 volts. D1 prevents the reverse voltage from the relay coil to transistor.
If you needs provides output the result is the opposite. It is possible to make jumper J1 resistor R7 is connected to the positive power supply 5 volts. The Q3 was driven provides work. At pin 15 of IC1 to ground So as to receive a logic “0”.
Determining circuits work in the dark or light. Can be done by the resistor value based on the light or LDR1 at input pin 12. Through the resistor R2. The sensitivity of the sensor can be adjusted to VR2.
Features end of project here is the delay before starting work. Using only 3 unit only are R5,VR3 and C9 will be the RC Constance Times. The delay time can be set by adjusting VR3.
The IC1 has received the +5 volts from IC2(78L05). Which serves to reduce the voltage from 9-12 volts input pin 1 of IC1.
How to build projects
You can make PCB layout as Figure 2 and in Figure 3 is the components layout of this projects.
The placing various components carefully, for is the polarity of the electrolytic capacitors and diodes correctly,Pin of the IC1,IC2 are not an error.
Tuning and testing.
First, adjust VR1 to the center. Then adjust VR2 and VR3 to lowest position.(Rotate counterclockwise to the end.) Then the power. Then try to move the PIR. LED1 will flash to the rhythm of the movement.
Later is a customizable delay. Use hands move on the PIR. Then adjust VR3, provides LED2 is lit. When the hand back and forth for about 3 seconds to set the delay time to 3 seconds. In this project can select up to 30 seconds.
Other circuits are recommended.
- Ultrasonic motion detector project with versatile controls
- The PIR Movement detector with light-activated
- Smoke detector circuit
- Insect repellent device using ic 4047