Light-sensitive Alarm Project
The circuit detects a sudden shadow falling on the light-sensor and sounds the bleeper when this happens. The circuit will not respond to gradual changes in bri...
Dummy Alarm Project
This Dummy Alarm project makes an LED flash briefly once every 5 seconds to imitate the indicator light of a real alarm. The circuit is designed to use very lit...
mobile incoming call indicator
This circuit can be used to escape from the nuisance of mobile phone rings when you are at home. This circuit will give a visual indication if placed near a mob...
transistors IR Emitter/Detector with 555 timer alarm
This circuit detects when a tube is empty and pulses a piezo buzzer in. 5 second intervals. I have it working with 5v on a breadboard, but I need to move it to ...
Siren for Factories
This is powerful siren circuit diagram. You can get lots of supports from this circuit because you can use this circuit for your alarm circuit then you will be ...
COLLEGE QUIZ BUZZER
Manual buzzers used for quiz competitions in schools and colleges create a lot of confusion in identifying the first respondent. Although there are circuits usi...
Piezoelectric alarm rings clear as a bell
A common piezoelectric alarm, such as the Murata (Smyrna, GA) PKB5-3A shown, has many valuable attributes. It is compact, lightweight, efficient and reliable. H...
Circuit Detects Phone-Line Breaks
Alarm system designs often require circuitry that can detect whether a phone line is active or broken. With this type of design, the primary difficulty is drawi...
Over-Temperature Alarm Circuit Uses Common Inexpensive Components
Over-Temperature Alarm Circuit Uses Common, Inexpensive Components | Negative-temperature-coefficient (NTC) thermistor, ICs....
Electronic Keypad Combination Lock
When wired to a ten-digit keypad, the circuit will recognize one 4 digit combination out of a possible 5040 codes. When the programmed four-digit combination is...
Factory Alarm
The frequency is controlled by the pin 5 of the IC. When the supply is switched ON, the capacitor charges slowly and this alters the voltage at pin 5 of the IC ...
AC Power Monitor
This AC Power Monitor continuously watches the AC power line voltage for both under-voltage and missing cycles. When it detects a total of 5 or 6 consecutive mi...
Infrared Alarm Barrier Circuit
This infrared alarm barrier can be used to detect persons passing through doorways, corridors and small gates. The transmitter emits a beam of infrared light wh...
smoke detector alarm schematic re46c140
Using the RE46C140 circuit can be designed a very simple smoke detector alarm using few external electronic components. The RE46C140 IC is a low power CMOS phot...
scr high power alarm driver circuit design
A very simple high power alarm driver electronic project can be designed using this circuit diagram. This high power alarm driver electronic project is based on...
Electronic Siren with Multitone
This multitone electronic siren is useful for burglar alarms, reverse horns, etc. It produces five different audio tones and is much more earcatching than a sin...
the remote intellectual pronunciation anti-theft alarm system design of the one-chip computer
Take precautions against the coefficient is low, the safety is bad, the applicable space is smaller and smaller. With the development of science and technology,...
the multi-channel system design of wireless safety protection of the infrared detection principle
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Design of a kind of simple and practical telephone alarm system
At present, it is numerous to adopt the telephone line as long-range control and alarm system of the transmission medium, associated too more research [1, 2 ]. ...
Digital Red Light Jump Checking System with RF Transmitter
digital red light jump checking system with RF transmitter. By implementing this project we can trace the red light jumping car with number and the time...