12C508 Smart Lock: The base sends a data
sequence (the password) which is recognized by the
key. The key checks the sequence and -if it
recognizes it -sends to the base another data
sequence, 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
consumers. |
4 Digit Keypad |
5 Zone Alarm Circuit |
A Basic RF Transmitter for PIR Sensors |
Active IR Motion Detector |
Alarm Control keypad |
Alarm Loop Sensor (LM3915) |
Almost Ultrasonic Motion Sensor |
Anti Theft Motorcycle Alarm |
Anti Theft Security for Car Audios: |
Auto Burglar Alarm: This alarm circuit is
based on two555 Timers. The alarm will sound your
car horn if anyone opens the car door while the
circuit is armed. The Timers will allow you to leave
the car without sounding the horn. To turn the
circuit on S1 must be closed. To set the alarm, open
S2 ( it is normally closed ) this will give you
about5 seconds to get out and close the door. The
exit delay Time is set by R1 and C1. If anyone opens
the doors for more then two seconds the horn will
sound until power is removed from the circuit. The2
second Time is set by R2 and C2. If you open the
door, you must deactivate the alarm by closing S2.
This very basic circuit could be used for a home
also. |
Automatic Entry Control System |
Car Burglar Alarm |
Combination Lock (PIC16F84) |
Combination Lock (Simple Version) |
Combination Lock: This circuit is very basic
to build. To open a the lock which is connected to
the K1 Load. you must press each momentary switch in
the correct sequence. The sequence used in this
circuit is S1,S2,S3,S4. If any of the other switches
are pressed the circuit will reset and you will need
to start over. Depending on how you wire the
switches, you can use any4 switch combination
|
Cut Phone Line Detector #1: Can be used to
alarm security system |
Digital Combination Lock: |
Digital Entry Lock: |
Door/window sensor resists tampering
PDF contains multiple circuits - scroll to find this
circuit
|
Electronic Card Lock System |
Electronic Door Codelock |
Electronic Lock |
Enhanced Alarm Keypad |
Fridge Door Alarm |
Gate Alarm Circuit |
Home Security Project |
Infrared gate for Door |
Intruder Radio Alert System |
Low Power RFID Transponder |
Luggage Security System |
Micropower Wireless Motion Detector Transmitter
|
Miniature Loop Alarm |
Modular Burglar Alarm |
Moisture Alarm |
Motorcycle Alarm |
Novel Buzzer |
Oscillating output improves system security:
Many electronic-control systems have digital outputs
that use transistors. One method of improving the
security in these outputs is to use an oscillating
signal to represent a logic-high state instead of a
fixed voltage level (Figure 1). This type of signal,
a dynamic variable, can drive the circuit shown in
Figure 2... |
Passive Infrared Pyroelectric Infrared Motion Sensor |
Perimeter Monitor: Using a single cable such
as speaker wire or doorbell cable, this circuit can
be remotely positioned, for example, at the bottom
of a garden or garage, and used to detect all sound
in that area. The cable can be buried in a
hosepipe or duct and is concealed out of sight. The
mic is an ordinary dynamic mic insert and should be
housed in a waterproof enclosure with the rest of
the circuit. |
Personal Silent Alarm System |
PIR Motion Detector Light Controller |
PIR Motion Detector |
Proximity Alarm |
Proximity Switch |
Pyroelectric Infrared Motion Sensor |
RF Alarm |
Simple Alarm System |
Simple Electronic Lock Uses Single-Transistor
Circuit:
Electronic Design - Ideas for Design /
Building on the recent Design Brief theme of one-pin
keypads, this design uses only one analog
microcontroller (MCU) input to scan numerous keys,
plus one resistor per key and another resistor and
capacitor. The circuit is simply a crude...
|
Single Button Lock Provides High Security:
PDF contains multiple circuits - scroll to find this
circuit. |
Single Zone Alarm |
TinyTwo Zone Alarm |
Touch Activated Alarm |
Touch Activated Switch |
Touch Triggered Alarm |
Toxic Gas Detector |
Ultrasonic Motion Detector |
Ultrasonic Remote Control & Alarm |
Universal Alarm System |
Warning Strobe Flasher for Alarm Systems |
Wire Loop Alarm |