Mini Alarms
This is a selection of small self-contained alarm circuits. They have a very low standby current; and are suitable for battery operation....
Mini Alarms
This is a selection of small self-contained alarm circuits. They have a very low standby current; and are suitable for battery operation....
Low Voltage Alarm
This low voltage circuit can be used to monitor batteries and other volatile sources of current for problems. The circuit sounds an alarm and lights an LED, but...
Low Voltage Alarm
This low voltage circuit can be used to monitor batteries and other volatile sources of current for problems. The circuit sounds an alarm and lights an LED, but...
Stun Gun Circuit
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...
Stun Gun Circuit
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...
Home security system
The security system application and program offers a simple demonstration of the BASIC Serial Interface. By adding only a few door and window switches, a transi...
Home security system
The security system application and program offers a simple demonstration of the BASIC Serial Interface. By adding only a few door and window switches, a transi...
Two HiJack Alarms
The first circuit was designed for the situation where a hijacker forces the driver from the vehicle. If a door is opened while the ignition is switched on - th...
Two HiJack Alarms
The first circuit was designed for the situation where a hijacker forces the driver from the vehicle. If a door is opened while the ignition is switched on - th...
Gate Alarm
Figure 1 represents a cheap and simple Gate Alarm, that is intended to run off a small universal AC-DC power supply. IC1a is a fast oscillator, and IC1b a slow ...
Gate Alarm
Figure 1 represents a cheap and simple Gate Alarm, that is intended to run off a small universal AC-DC power supply. IC1a is a fast oscillator, and IC1b a slow ...
Fuse Monitor / Alarm
It came to me in a flash. A simple way to see if a fuse has blown without removing it from its holder.
Its not often you can design a circuit using just two co...
Fuse Monitor / Alarm
It came to me in a flash. A simple way to see if a fuse has blown without removing it from its holder.
Its not often you can design a circuit using just two co...
Enhanced 5 Digit Alarm Keypad
This is an enhanced 5 digit keypad which may be used with the Modular Alarm System....
Enhanced 5 Digit Alarm Keypad
This is an enhanced 5 digit keypad which may be used with the Modular Alarm System....
Doorknob Proximity Alarm for wooden door
Reverse engineered circuit diagram of a popular retail doorknob alarm. It contains a small transmitter and the doorknob acts as an antenna so it will not work o...
Doorknob Proximity Alarm for wooden door
Reverse engineered circuit diagram of a popular retail doorknob alarm. It contains a small transmitter and the doorknob acts as an antenna so it will not work o...
Door Alarm
This circuit emits a beep and/or illuminates a LED when someone touches the door-handle from the outside. The alarm will sound until the circuit will be switche...
Door Alarm
This circuit emits a beep and/or illuminates a LED when someone touches the door-handle from the outside. The alarm will sound until the circuit will be switche...