APPLIED ELECTRONIC CIRCUIT
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5 Zone Alarm Circuit
Each zone alarm uses a normally closed contact. These can be micro switches or standard alarm contacts (usually reed switches). Zone 1 is a timed zone which must be used as the entry and exit point of the building. Zones 2 - 5 are immediate zones, which will trigger the alarm with no delay. Some RF …
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Light-Sensitive-Alarm
The Alarm 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 brightness to avoid false alarms. The bleeper sounds for only a short time to prevent the battery running flat. Normal lighting can be us …
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Sun-Up Alarm
The Sun-Up Alarm circuit can be used to provide a audible alarm for when the sun comes up or it can be used in a dark area and detect when a light comes on. It can also be used to detect a light beam, headlights etc. The circuit works as follows.The phototransistor is very sensitive to light. (Any p …
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Touch Switch Circuit
This electronic circuit uses a 555 timer as the bases of the touch switch. You can learn more about 555 timers in the Learning section on my site. When the plate is touched the 555 timer is triggered and the output on pin 3 goes high turning on the LED and the buzzer for a certain period of time. Th …
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Low Cost Fire Alarm Circuit Using Transistor
Here's a cheap fire alarm circuit for building one. When there is a fire breakout in the room the temperature increases. This ultra compact and low-cost fire alarm senses fire breakout based on this fact.Transistor BC177 (Q1) is used as the fire sensor here. When the temperature increases the leakag …
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Proximity Detector Using CS209
This is a simple proximity detector using IC CS209. The CS209A is a bipolar monolithic integrated circuit for use in metal detection/proximity sensing applications.The CS209A contains an oscillator set up by an external parallel resonant tank and a feedback resistor connected between pin 2 & 3.T …
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Fire Alarm Using Thermistor
In this fire alarm circuit, a thermistor works as the heat sensor. When temperature increases, its resistance decreases, and vice versa. At normal temperature, the resistance of the thermistor (TH1) is approximately 10 kilo-ohms, which reduces to a few ohms as the temperature increases beyond 100°C. …
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Fire Alarm Circuit
This electronic circuit is a simple fire alarm circuit based on a LDR and lamp pair for sensing the fire. The alarm works by sensing the smoke produced during fire.The circuit produces an audible alarm when the fire breaks out with smoke.When there is no smoke the light from the bulb will be directl …
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Car Battery Alarm with CA3140
This electronic circuit is for Checking battery in car. It use IC CA3140 and Transistor circuit.click here for schematicSource: elecfree.com
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Modular Burglar Alarm
The Basic Alarm Circuit has an automatic Exit/Entry Zone - an Instant Alarm Zone that will accept both normally-closed and normally-open triggering devices - and an "Always On" 24-hour Personal Attack/Tamper Zone. By using the Expansion Modules - you can add as many extra alarm zones as you require. …
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Electronic Candle Blow Out
This electronic design was developed by request of a correspondent having made a sort of LED candle and needing to switch off the LED with a puff. This simple, easy to build gadget can be useful as a prop for Halloween and Christmas season, shows and the like. Q2 & Q3 form a self-latching pair t …
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Fogger Controller
Foggers used to generate fog and smoke effects operate by heating a special fogger fluid. They consist of a heting element which is kept in the right temperature using a thermostat. When the operator want to generate smoke, he/she presses the controller button which starts the pump which pumps fog f …
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Water Level Alarm
This circuit not only indicates the amount of water present in the overhead tank but also gives an alarm when the tank is full. The circuit uses the widely available CD4066, bilateral switch CMOS IC to indicate the water level through LEDs.When the water is empty the wires in the tank are open circu …
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Wireless Antitheft Alarm
This FM radio-controlled anti- theft alarm can be used with any vehicle having 6-12 volt DC supply system. The mini VHF, FM transmitter is fitted in the vehicle at night when it is parked in the car porch or car park. The receiver unit with CXA1019, a single IC-based FM radio module, which is freely …
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Rain Alarm
This circuit gives out an alarm when its sensor is wetted by water. A 555 astable multivibrator is used here which gives a tone of about 1kHz upon detecting water. The sensor when wetted by water completes the circuit and makes the 555 oscillate at about 1kHz.The sensor is also shown in the circuit …
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Smoke Detector Circuit - Fire Alarm
This circuit uses a very simple approach to detecting smoke in the air. Quite simply, it uses a bulb as a light source, and an LDR (Light Dependent Resistor) as a light detector. As fire smoke comes between the bulb and LDR, the resistance of the LDR changes, which in turn trigger an alarm.This prob …
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Phone Line Status Indicator
This Phone Line Status Indicator circuit has been designed by Gabriele Bandini. His home is full of telephones, modems, and... kids. After a dozen of modem crashes, he decided to put an indicator LED on every phone plug to show to the family when the phone line is free.If you have a FAX and a phone …
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Wireless Alarm
Making yourself an alarm is both useful and interesting: but the best part is when you take the remote control out of your pocket, and switch on the alarm while saying to your friends: "I've done it in a weekend".Making yourself an alarm gives you maximum flexibility: as this project works according …
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Build Yourself a Witness Camera
The Witness Camera is an automated, self-recording surveillance camera, that uses a gigabyte-class flash card as recording media. I designed the Witnesscam because available surveillance solutions were too expensive or impractical for home use.The system from a VGA CMOS colour camera, a passive-infr …
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Build a DS1621 PC Thermometer
This incredibly simple thermometer plugs on any free serial port. Does not make use of any programmable components as microcontrollers. It gives temperature readings accurate to 0.5°C with no calibration. It's cheap, so I've put one on any PC I use. And it's soooo nice to have the temperature shown …
APPLIED ELECTRONIC CIRCUIT
