Sun-Up Alarm
The Sun-Up Alarm 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...
Sun-Up Alarm
The Sun-Up Alarm 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...
Snore Alarm
The idea behind this snore alarm, is just to rouse the snorer, not the entire household. To wake the sleeper, vibration is used, not an audible alert. The vibra...
Snore Alarm
The idea behind this snore alarm, is just to rouse the snorer, not the entire household. To wake the sleeper, vibration is used, not an audible alert. The vibra...
Single Zone Alarm
A single zone alarm circuit with entry and exit delay and other facilities. The circuit features automatic exit and entry delays, timed bell cut-off and system ...
Single Zone Alarm
A single zone alarm circuit with entry and exit delay and other facilities. The circuit features automatic exit and entry delays, timed bell cut-off and system ...
Radio Wave Alarm
This simple circuit is sure to have the police beating a path to your door - however, it has the added advantage of alerting you to their presence even before t...
Radio Wave Alarm
This simple circuit is sure to have the police beating a path to your door - however, it has the added advantage of alerting you to their presence even before t...
Power-line outage flashes red alert
This Design Idea expands on a circuit in a previous one to configure a power-outage detector with a flashing alarm (Figure 1, Reference 1). The circuit plugs in...
Power-line outage flashes red alert
This Design Idea expands on a circuit in a previous one to configure a power-outage detector with a flashing alarm (Figure 1, Reference 1). The circuit plugs in...
Personal Alarm
This circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and connected to the hand ...
Personal Alarm
This circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and connected to the hand ...
Audio 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 use...
Audio 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 use...
Novel Buzzer
This novel buzzer circuit uses a relay in series with a small audio transformer and speaker. When the switch is pressed, the relay will operate via the transfor...
Novel Buzzer
This novel buzzer circuit uses a relay in series with a small audio transformer and speaker. When the switch is pressed, the relay will operate via the transfor...
Modular Burglar Alarm
This circuit features automatic Exit and Entry delays and a timed Bell Cut-off. It has provision for both normally-closed and normally-open contacts, and a 24-h...
Modular Burglar Alarm
This circuit features automatic Exit and Entry delays and a timed Bell Cut-off. It has provision for both normally-closed and normally-open contacts, and a 24-h...
Miniature Loop Alarm
Simple construction, reliable operation, very small power consumption, and, most of all, small size. I started with CMOS logic gates, but was soon forced to aba...
Miniature Loop Alarm
Simple construction, reliable operation, very small power consumption, and, most of all, small size. I started with CMOS logic gates, but was soon forced to aba...