This is a complete alarm system with 5 independent zones suitable for a small office or home environment. It uses just 3 CM IC`s and features a timed entry / exit zone, 4 immediate zones and a panic button. There are indicators for each zone a “system armed” indicator. The schematic is as follows: Circuit […]
No related posts.
The IC is a quad 2 input “AND” gate, a CMOS 4081. These gates only produce a HIGH output, when BOTH the inputs are HIGH. When the key wired to `E` is pressed, current through R1 and D1 switches Q5 on. The relay energises; and Q5 is `latched on` by R8. Thus, the Alarm is […]
Project Objectives To explore how different motion detectors operate. To successfully build and test an ambient-light-ignoring active IR motion detector. Background There are a wide variety of motion detectors available currently. To allow a better understanding of motion detectors, the following section provides a detailed description of a few different types. Ultrasonic Motion Detectors Ultrasonic […]
No related posts.
The circuit above above makes use of the CMOS 4017 decade counter IC. Each depression of a switch steps the output through 0 – 9. By coupling the output via an AND gate to the next IC, a predefined code has to be input to create the output. Each PBS switch is debounced by tw1o […]
This circuit is an Electronic Locker. It is controlled by a switches combination (by a code). There is a switch matrix on the door of the locker. This one is a unit of switches connected into 4 arranged of 4 columns for a total of eight terminals. When we press on a switch, this one […]
Parts: R1____________220K 1/4W Resistor R2____________470R 1/2W Resistor R3____________390R 1/4W Resistor R4______________1K5 1/4W Resistor R5______________1R 1/4W Resistor R6_____________10K 1/4W Resistor R7____________330K 1/4W Resistor R8____________470R 1/4W Resistor R9____________100R 1/4W Resistor C1____________330nF 400V Polyester Capacitor C2_____________10΅F 63V Electrolytic Capacitor C3____________100nF 63V Polyester Capacitor C4_____________10nF 63V Polyester Capacitor D1-D5________1N4007 1000V 1A Diodes D6______________LED Green (any shape) D7___________1N4148 75V 150mA […]