Security circuit
Simple version. Full version location at http://circuitsradio.com
View original of this circuit: http://circuitsradio.com/schematics/electrical-engineering/Security/index.html
5 Zone Alarm
5 Zone alarm circuit
A Basic RF Transmitter for PIR Sensors
Active IR motion detector
Aircore (Metal detector theory) (162 Kb)
Alarm Circuits
Alarm control keypad
Almost Ultrasonic Motion Sensor
Audio Perimeter Monitor
Automatic Emergency Light
Barrys Magnetic Levitation. Magnetic levitator. The pages include complete design details for an antigravity relay to levitate small iron parts.
Basic RDS Encoder Unit
BFO Theory (Metal detector theory) (59 Kb)
Bootstrp/ PLL ( Phase Locked Loop) (Metal detector theory) (33 Kb)
Buzzer Circuit
Car Anti-Theft Wireless Alarm
Car indicator alarm
Cheesemd1 (Metal detector theory-BFO) part1 (181 Kb)
Cheesemd2 (Metal detector theory-BFO) part2 (328Kb)
Combination Lock (PIC16F84)
Deer Repellent (18k) This seismic sensor can detect and frighten away intruders.
Digital combination lock
Digital Combination Lock
Digital entry lock
Dongle -serial port (12C508A) This device is NOT a professional dongle. You can use it to protect your software , but you must agree with its major disadvantage: it needs one of the COM ports on your PC. The advantages are the low cost and simplicity.
Door knob alarm (PDF)
Doorphone intercom
Dummy alarm
Economy radar detector
Electronic snap
Electronic Card- Lock System
Electronic Code Lock
Electronic door codelock (PIC projects)
Electronic door codelock (PIC16F84)
Electronic lock
Electronic lock
Electronic Security door key 1
Electronic Security door key 2
Electronic Siren
Electronic siren
Enhanced 4 Digit Alarm Keypad
Enhanced 5 Digit Alarm Keypad
Enhanced Alarm Keypad
Fire Alarm
Flashing Flashlight - Meant for use as an emergency flashlight for your glove compartment.
Flashing Road Barricade
Flickering Fire Light - LED or Bulb flicker shimmer randomly like candle flame or fire
FM bug
FM Telephone Bug
FM Telephone Bug
FM Transmitter
FOUR-IN-ONE BURGLAR ALARM
Fridge Alarm (9k) Alerts you when the refrigerator door is left open.
Fridge door alarm
Fridge door Alarm. Beeps if you left open the door over 20 seconds. 3V battery operation, simple circuitry
Frost Alarm or Cold Activated Switch
Garage Door Opener Scanner
Gate Alarm
Gate alarm circuit
Gate Alarm Circuit
Geiger counter
High Temperature ALARM
Home security project
IC Controlled Emergency Light with Charger
Low power RFID transponder
Magnetic Gun
Metal detector
Metal Detector Description James Trevelyan (Metal detector theory)
Micro-power over temperature alarm (PDF)
Miniature loop alarm
Miniature Loop Alarm
Modular Burglar Alarm
Modular Burglar Alarm
Moisture alarm
Motorcycle alarm
Motorcycle Alarm
Novel Buzzer
One-IC two-tones Siren. Double tone Police sound. Single tone old ambulance sound
Parallel port dongle (12C508A) By using the PIC 12C508 MCU from Microchip, we can make a cheap and simple hardware protection key (dongle).
Perimeter monitor
Personal Alarm - These handheld piezo screamers are also known as rape alarms. They are a very loud siren.
Personal silent alarm system
PIR motion detector
Proximity alarm
Proximity switch
Radio Wave Alarm
RF Alarm
Simple alarm system
Single Zone Alarm
Small Radio Transmitter
Small Radio Transmitter
Smart lock (12C508A). The base sends a data sequency (the password) which is recognized by the key. The key checks the sequency and -if it recognises it -sends to the base another data sequency, as an answer to the password. At the time when the base gets a correct answer (which means that the key has been introduced), the relay is put into action, and it can command a number of consummers.
Stun Gun
Stun gun (1)
Stun gun (2)
Stun gun (3)
Telephone line monitor. If you feel that somebody is tampering with your telephone line you might find this little circuit useful. It detects if there is another telephone connected to the line, if there is a short or an open line. (simple)
The Surfer’s Preserver. It is a simple device that prevents other phones in the house from disrupting your critical Internet session by disconnecting them from the line while you surf! It is also useful in preventing eavesdropping from other extensions.
Tiny 2-zone alarm
Touch activated alarm system
Toxic Gas Detector
Transmiter Detector
Transmitter
Two tone siren
UltraSonic Radar
Ultrasonic remote control & alarm system
Water Activated Alarm
Water Activated Alarm
Water level alarm
Water Level Alarm
Water seepage alarm (PDF)
Wire loop alarm
View original of this circuit: http://circuitsradio.com/schematics/electrical-engineering/Security/index.html