Advertisement
Room Noise Detector Circuit – Circuit Schematic
Room Noise Detector Circuit
This circuit is intended to signal, through a flashing LED, the exceeding of a fixed threshold in room noise, chosen from three fixed levels, namely 50, 70 & 85...
Whistle Responder Schematic circuit – Circuit Schematic
Whistle Responder Schematic circuit
This device beeps intermittently for about two seconds when a person in a range of around meters emits a whistle. The first two inverters contained in IC1 are u...
Keys Finder circuit – Circuit Schematic
Keys Finder circuit
Imagine that is morning, you barely anticipate the bus for work and you can`t find your keys. If you suffer from this situation frequently, this circuit is idea...
Water Level Alert Circuit – Circuit Schematic
Water Level Alert Circuit
This circuit will emit an intermittent beep (or will flash a LED) when the water contained into a recipient has reached the desired level. It should be mounted ...
Water Alarm Circuit – Circuit Schematic
Water Alarm Circuit
Have you ever seen the stairs to one of the upper stories in your house turn into a waterfall? Or maybe you ve come home to find your aquarium fish trying to sw...
Mains Remote-Alert circuit – Circuit Schematic
Mains Remote-Alert circuit
Pressing the pushbutton of the transmitter, a sound and/or light alert is activated in the receiver. The system uses no wiring or radio frequencies: the transmi...
Remote Doorbell Warning Switch circuit – Circuit Schematic
Remote Doorbell Warning Switch circuit
It is quite easy to miss the sound of a doorbell if you are watching TV, this circuit gets round the problem by providing a visual indication, i. e. a lamp. As ...
Doorbell Memory Circuit – Circuit Schematic
Doorbell Memory Circuit
If you re expecting an important visitor but you just have to step out for a moment, an electronic doorbell memory can come in handy so you can see whether some...
Economy radar detector circuit – Circuit Schematic
Economy radar detector circuit
This circuit uses a 1458 dual op-amp to form a radar detector. C1 is the detector of the radar signal. The first op-amp forms a current-to-voltage converter and...
Two Simple Relay Based Motorcycle Alarms circuit – Circuit Schematic
Two Simple Relay Based Motorcycle Alarms circuit
You can use them to protect your motorcycle but have many more applications. If you use relays with 6-volt coils - they`ll protect your "Classic Bike". Both ala...
A Cmos Based Motorcycle Alarm circuit – Circuit Schematic
A Cmos Based Motorcycle Alarm circuit
This circuit features an intermittent siren output and automatic reset. It can be operated manually using a key-switch or a hidden switch; but it can also be wi...
A 555 -Timer Based Motorcycle Alarm circuit – Circuit Schematic
A 555 -Timer Based Motorcycle Alarm circuit
This circuit features an intermittent siren output and automatic reset. It can be operated manually using a key-switch or a hidden switch; but it can also be wi...
A Transistor Based Motorcycle Alarm circuit – Circuit Schematic
A Transistor Based Motorcycle Alarm circuit
This circuit features a timed output and automatic reset. It can be operated manually using a key-switch or a hidden switch. By adding an external relay, it wil...
Emergency Light and Alarm circuit – Circuit Schematic
Emergency Light and Alarm circuit
This circuit is permanently plugged into a mains socket and NI-CD batteries are trickle-charged. When a power outage occurs, the lamp automatically illuminates....
Electronic Security Door Key circuit – Circuit Schematic
Electronic Security Door Key circuit
A different circuit of electronic lock very simple, one and does not need a lot of materials in order to it is manufactured.....
Electronic Door Release circuit – Circuit Schematic
Electronic Door Release circuit
This circuit is designed to operate an electrical door-release mechanism - but it will have other applications. When you enter the four-digit code of your choic...
Keypad Controlled Switch No2 circuit – Circuit Schematic
Keypad Controlled Switch No2 circuit
This is a simplified version of the 4-Digit Keypad Controlled Switch. I have modified the design to reduce the complexity of the circuit - and the number of com...
A 4-Digit Keypad Controlled Switch circuit – Circuit Schematic
A 4-Digit Keypad Controlled Switch circuit
This is a Universal version of the Four-Digit Alarm Control Keypad. I have modified the design to free up the relay contacts. This allows the circuit to operate...
Vehicle Anti-Hijack Alarm No3 circuit – Circuit Schematic
Vehicle Anti-Hijack Alarm No3 circuit
Like the first two Hijack Alarms - if a door is opened while the ignition is switched on - the circuit will trip. And after a few minutes delay - when the thief...
A Cmos Based Vehicle Anti-Theft Alarm circuit – Circuit Schematic
A Cmos Based Vehicle Anti-Theft Alarm circuit
This car alarm circuit features Exit and Entry delays, an instant alarm zone, an intermittent siren output and automatic Reset. By adding external relays you ca...