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Home related Circuits
Smart Trailing Socket
Mains sockets switched automatically by a Control Socket
Up to 1000W switched power
Fridge door Alarm
Beeps if you leave open the door over 20 seconds
3V battery operation, simple circuitry
Plant Watering Watcher
A flashing LED signals the necessity to water a plant
Very low current consumption - 3V powered circuit
Ultra-simple Voltage Probe
Detects 1.8 to 220 Volts DC or AC
Minimum parts counting
Digital Remote Thermometer
Remote sensor sends data via mains supply
Temperature range: 00.0 to 99.9 °C
Self-powered Fast Battery-Tester
Tests 1.5 to 15 Volt cells
Two-LED display, no power supply required
Room Noise Detector
One LED monitors three levels: 50, 70 & 85 dB
Useful to detect too noisy environments
Battery-powered Night Lamp
Ultra-low current drawing
1.5V battery supply
Infra-red Level Detector
Useful for liquids level detection and proximity devices
Up to 50 cm. range, optional relay operation
Nocturnal Animals Whisker
A low-rate flashing lamp drives away undesired visitors
Automatic on-off operation
Live-line Detector
Detects the presence of a live mains conductor
Minimum parts counting
Heating System Thermostat
Controlled by indoor and outdoor temperature
Simple, high reliability design
Mains Remote-Alert
Beeper and/or LED remotely-operated via mains supply line
Simple circuitry, easy to build units
Cellular Phone calling Detector
Flashes a LED when detecting an incoming call
Powered by one 1.5V cell
AC Current Monitor
Senses high current-flow into power cables
No wire-cutting, three versions available
Temperature-controlled Fan
Gradually increases speed as temperature increases
Widely adjustable temperature range
Self-powered Door-bell Watcher
Detects if the door-bell has rung in your absence
Also suitable for different electric appliances
Dark-activated 230V Lamp
Compact circuitry using small-size parts only
Can be wired in parallel to existing switches
Energy Leak Detector
High sensitivity, portable temperature comparator
Detects draughts around doors, windows, etc.
Broken Charger-connection Alert
Detects if a device is not properly connected to its supply
Suitable for battery chargers, portable appliance supplies etc.
Award winner!
Published on
ELECTRONICS WORLD
"Circuit Ideas"
October 1999 issue, page 819
Bedside Lamp Timer
30 minutes operation
Blinking LED signals 6 last minutes before turn-off
Timed Beeper
Beeps 7.5 seconds after a preset time
Adjustable time settings: 15 s. 30 s. 1 min. 2 min. & others
Award winner!
Published on
ELECTRONICS WORLD
"Circuit Ideas"
April 2001 issue, page 299
Courtesy Light
15 seconds delayed switch-off
A good idea for bedroom lamps
Door Alarm
Hangs up on the door-handle
Beeps when someone touches the door-handle from outside
Award winner!
Published on
ELECTRONICS WORLD
"Circuit Ideas"
September 2001 issue, page 708
Emergency Light & Alarm
Powered by two AA NI-CD batteries
Four switchable options
Clap Relay
Clap sensitive on-off Relay
3V Battery operated, small portable unit
Bidirectional Photoelectric System
Detects and counts inputs and outputs
Suited to control Lamps, Household Appliances etc.
Award winner!
Published on
ELECTRONICS WORLD
"Circuit Ideas"
April 2005 issue, page 52
Fridge door Alarm (2nd Version)
Alternative version of the popular circuit
3V battery supply - Still operating at 1.3V
Water-level Indicator
Simple, two-wire, remote monitoring unit
Three-LED level display, 9V battery powered
Water-level Alert
Beeper or flashing LED alert
1.5V battery powered portable unit
Temperature-controlled 12V dc Fan
Suitable for computer cooling fans
LED motor speed indicator
120 and 240Vac LED Voltage Indicator
Useful for power lines control
Simple, transformerless circuitry
IR Remote-Control Checker
Suitable for any Infra-red emitting device
3V battery supply
Water Pump Relay Control
Water reservoir automatic level control
Simple circuitry - 12V supply
230Vac Lamp Toggle Switch
Compact, transformerless circuitry
No relays employed
Cell-Phone calling Actuator
Drives a relay when an incoming call is detected
12V dc supply
Power Outage Warning
5 to 15V supply - LED indicator
Adjustable time detection
Touch Counter
The counter is advanced by one touching a wire of the LED
Suitable for many applications
Displacement Alarm
Warns if an object is moved
Small gadget - 9V Battery supply
Volumetric Sensor Alarm
Detects small variations in air pressure
Can be battery powered (6/12V)
Volumetric Sensor Alarm
