Advertisement
Touch Activated Alarm System – Circuit Schematic
Touch Activated Alarm System
The 555 can be almost any type, they are all pin-compatible. Although some CMOS types may not have enough power to drive the transistor, in that case use an ord...
Single Zone AlarmCircuit - Project – Circuit Schematic
Single Zone AlarmCircuit - Project
The circuit features automatic exit and entry delays, timed bell cut-off and system reset. It has provision for normally open and normally closed switches and w...
Proximity AlarmCircuit Project – Circuit Schematic
Proximity AlarmCircuit Project
...
Personal Silent Alarm System Diagram Project – Circuit Schematic
Personal Silent Alarm System Diagram Project
The TTY and the detector-transmitter unit are connected to separate phone jacks on the same line. When the ring sensor detects an incoming phone call, it activa...
Novel BuzzerCircuit – Circuit Schematic
Novel BuzzerCircuit
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...
Motorcycle AlarmCircuit – Circuit Schematic
Motorcycle AlarmCircuit
...
Modular Burglar Alarm Project – Circuit Schematic
Modular Burglar Alarm Project
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...
Gate AlarmCircuit Project – Circuit Schematic
Gate AlarmCircuit Project
...
Frost AlarmCircuit Project – Circuit Schematic
Frost AlarmCircuit Project
The thermistor used has a resistance of 15k at 25 degrees and 45k at 0 degrees celsius. A suitable bead type thermistor is found in the Maplin catalogue. The 10...
Emergency Light & Alarm Project – Circuit Schematic
Emergency Light & Alarm Project
...
Digital Combination LockCircuit Project Tutorial – Circuit Schematic
Digital Combination LockCircuit Project Tutorial
The circuit above makes use of the CMOS 4017 decade counter IC. Each depression of a switch steps the output through 0 - 9. By coupling the output via an AND ga...
Alarm Control Electronic Keypad Project – Circuit Schematic
Alarm Control Electronic Keypad Project
The IC is a quad 2 input "AND" gate, a CMOS 4081. These gates only produce a HIGH output, when BOTH the inputs are HIGH. When the key wired to `E` is pressed, c...
Electronic Locks Circuits – Circuit Schematic
Electronic Locks Circuits
This circuit can be used to operate an electric strike or an electromagnetic lock on a door. It is not the door being opened/closed, but a small electromagnetic...
Door Bell Circuits – Circuit Schematic
Door Bell Circuits
...
Beeper & Buzzer Schematics – Circuit Schematic
Beeper & Buzzer Schematics
24v DC is a very popular voltage used in industrial settings. The circuit below was designed to accept four different 24v DC alarm input signals, which are then...
Fuse Monitor / Alarm circuit – Circuit Schematic
Fuse Monitor / Alarm circuit
...
Midnight Security Light Circuit – Circuit Schematic
Midnight Security Light Circuit
Most thefts happen after midnight hours when people enter the second phase of sleep called ˜paradoxical sleep. Here is an energy-saving circuit that causes the...
Ringing Phone Light Flasher circuit – Circuit Schematic
Ringing Phone Light Flasher circuit
You are asking how to connect up some lights so that when the phone rings, they flash. This is very useful in a situation were there is lots of noise and it is ...
Multitone Siren circuit – Circuit Schematic
Multitone Siren circuit
This multi-tone siren is useful for burglar alarms, reverse horns, etc. It produces five different audio tones and is much more ear-catching than a single-tone ...
Fire Alarm Using Thermistor circuit – Circuit Schematic
Fire Alarm Using Thermistor circuit
In this fire alarm circuit, a Thermistor works as the heat sensor. When temperature increases, its resistance decreases, and vice versa. At normal temperature, ...