All Electronic Projects

  • Circuit DiagramAutomotive Voltage Indicator

    Connecting this circuit to the battery of your vehicle, you will always know at a glance the approximate voltage available. An indication of battery voltage is useful to the motorist for monitoring t...

  • Circuit DiagramBattery Powered Imergency Light

    This circuit is usable as a Night Lamp when a wall mains socket is not available to plug-in an ever running small neon lamp device. In order to ensure minimum battery consumption, one 1.5V cell is use...

  • Circuit DiagramCellular Phone Calling Detector

    This circuit was designed to detect when a call is incoming in a cellular phone (even when the calling tone of the device is switched-off) by means of a flashing LED. The device must be placed a few ...

  • Circuit DiagramTemperature Controlled DC Fan

    Requested by some correspondents, this simple design allows an accurate speed control of 12V dc fan motors, proportional to temperature. A n.t.c. Thermistor (R1) is used as temperature sensor, drivin...

  • Circuit DiagramCircuit Board Tester

    This little circuit indicates the basic integrity of a printed board, detecting 0V, positive supply voltage from less than 3V to 30V and floating parts. If the probe is floating, as it would be in a ...

  • Circuit DiagramClap Relay

    This circuit was intended to activate a relay by means of a hand clap. A further clap will turn-off the relay. An interesting and unusual feature of this project is the 3V battery operation. The circ...

  • Circuit DiagramDark Activated Lamp

    This device allows one or more lamps to illuminate at sunset and turn off at dawn. Q1 and Q2 form a trigger device for the SCR, providing short pulses at 100Hz frequency. Pulse duration is set by R2 ...

  • Circuit DiagramEmergency Light and Alarm

    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. Instead of illuminating a lamp, an alar...

  • Circuit DiagramFire Alarm

    In this fire alarm circuit, a Thermistor works as the heat sensor. When temperature increases, its resistance decreases, and vice versa. At normal temperature, the resistance of the Thermistor (TH1) i...

  • Circuit DiagramInfra-Red Remote Control Receiver

    This is the schematics for infra-red remote control Receiver. This remote control receiver will be able to receive a transmitted tone from it's respective transmitter's infra-red LED. And this receive...

  • Circuit DiagramInfra-Red Remote Control Transmitter

    Here is the schematic diagram for an infa-red remote Transmitter. This remote transmitter transmits a tone using an infa-red LED. And this tone is decoded by the receiver. Since the receiver only swit...

  • Circuit DiagramLive Line Detector

    If the unit is brought close to a live conductor (insulated, and even buried in plaster) capacitive coupling between the live conductor and the probe clocks the counter, and causes the LED to flash 5 ...

  • Circuit DiagramPush Bike Light

    This design was primarily intended to allow automatic switch-on of push-bike lights when it gets dark. Obviously, it can be used for any other purpose involving one or more lamps to be switched on and...

  • Circuit DiagramTouch Activated Alarm

    Not much to tell here as the circuit speaks for itself. 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...

  • Circuit DiagramTransistor Pin Identifier

    A three-phase wave form is derived from the 350Hz ring-of-three oscillator formed by IC1A, IC1B and IC1C, and applied to the device under test via the LEDs. The oscillator wave form enables each pair ...

  • Circuit DiagramVariable DC Supply

    A Variable DC Power Supply is one of the most useful tools on the electronics hobbyist's workbench. This circuit is not an absolute novelty, but it is simple, reliable, "rugged" and short-proof, featu...

  • Circuit DiagramVerysimple Water Level Indicator Alarm

    The circuit uses a 555 timer wired as an astable oscillator and powered by the emitter current of the BC109C. Under dry conditions, the transistor will have no bias current and be fully off. As the pr...

  • Circuit Diagram12V Battery Tester

    This kit measures battery voltage. The red LED (closest to the IC) indicates a low status - 11.5Volts or less. The yellow LED indicates 50% charge - 12.0V. The green LED indicates 12.6V or full cha...

  • Circuit Diagram45W Class B Amplifier

    These goals were achieved by using a discrete-components op-amp driving a BJT complementary common-emitter output stage into Class B operation. In this way, for small output currents, the output trans...

  • Circuit Diagram12V Battery Tester-1

    This bar graph LED battery level indicator circuit is based on LM3914 monolithic IC from National Semiconductor that senses the voltage levels of the battery and drives the 10 light emitting diodes ba...