| ID | Title | Price | Type | Select |
| 1 | #95 Debarring Facility for your Telephone
Telephone is no more an item of luxury but a basic necessity of life. Last year, in certain regions, the government of India made areas falling within 200 km accessible through local telephones by dialing the local telephone number after dialing 95. However, the pulse rate for areas accessible through 95
dialling is 30 seconds (one pulse per 30 seconds) as against the pulse rate of 180 seconds applicable for normal local calls.
|
Rs 150
US$ 3 | Construction | |
| 2 | ‘On’/‘Off’ Ringer
This circuit produces an audio tone of around 450 Hz interrupted at the rate of 1.2 Hz. |
US$ 1
Rs 50 | Circuit Idea | |
| 3 | 0-100°C Temperature Detector
Here’s a temperature monitoring system capable of remote temperature reading without transmission losses in the conditioning circuit. |
US$ 1
Rs 50 | Circuit Idea | |
| 4 | 0-10V Amplifier
This circuit is useful in line synchronisation where the line speed reference voltage source is too weak to drive a synchronising machine. |
US$ 1
Rs 50 | Circuit Idea | |
| 5 | 0-24V Regulated DC Power Supply
This inexpensive circuit is that of a simple series voltage regulator and perhaps the simplest continuously variable regulated DC power supply. |
US$ 1
Rs 50 | Circuit Idea | |
| 6 | 1 Hz Master Oscillator
This inexpensive circuit is of a 1 Hz oscillator that gives satisfactory results, using only a few components.
|
US$ 1
Rs 50 | Circuit Idea | |
| 7 | 100-Segment Light Chaser
This is a low-cost, simple and easy to fabricate light chaser. |
US$ 1
Rs 50 | Circuit Idea | |
| 8 | 10-Band Audio Spectrum Analyser
This audio spectrum analyser, can pinpoint the deficiency in a particular listening environment. A virtually indispensable piece of equipment for the equaliser user. |
Rs 150
US$ 3 | Construction | |
| 9 | 10-Channel Touch Switch with Display
The circuit described here is of a touch switch with display which allows selection of one channel out of 10 channels,
by touching the touch plates. The touch plates can be replaced with a push to on-switch. When the touch plates are bridged
with finger, transistor T1 goes into conduction and triggers timer IC1 (555), which is wired in monostable mode. |
US$ 1
Rs 50 | Circuit Idea | |
| 10 | 12V, 3A Power Supply
This circuit provides a 12V regulated power supply with output
current up to 3 amperes. It is specially designed for use with 2m handheld rigs with linear power amplifier and CB portable QRP rigs. |
US$ 1
Rs 50 | Circuit Idea | |
| 11 | 16-Bit to any Set of 8-Bit Gang Selector
This circuit solves the problem of selecting any set of 8-bit outputs from the parallel 16-bit outputs of memory system or any other system. |
US$ 1
Rs 50 | Circuit Idea | |
| 12 | 16-way Clap-Operated Switch
Control your home appliances without getting out of your bed. You just have to clap in the vicinity of the microphone used in this circuit, which you can keep by the bedside. You can switch on/off up to four different electrical equipment (TV, fan, light, etc) in 16 different ways. |
US$ 1
Rs 50 | Circuit Idea | |
| 13 | 1Hz Clock Generator
Here, circuit of a low-cost, precision 1 Hz clock generator for digital clocks, timers etc. is presented. This circuit is built around IC1 (CD4060), IC2 (CD4027), a 32.768 kHz crystal, some resistors and capacitors. IC1 (CD4060) is a 14-bit binary
ripple counter and oscillator. It has internal oscillator and 14-stage ripple counter (binary). |
US$ 1
Rs 50 | Circuit Idea | |
| 14 | 20M, 4W QRP Transmitter
Using this small yet powerful 4W transmitter Hams (licenced amateur radio operators) can transmit Morse code signals to long distances in 20-metre band. Morse code communication with European and neighbouring countries is possible. |
US$ 1
Rs 50 | Circuit Idea | |
| 15 | 20-Metre CW/SSB Receiver-I
While some enterprising amateurs have aimed at achieving
the ultimate performance using sophisticated designs, some others work with simple receivers of the direct-conversion
type. Here, we have adopted a compromise approach. |
Rs 150
US$ 3 | Construction | |
| 16 | 20-Metre CW/SSB Receiver-II
BFO is crystal controlled and uses two crystals (8.9985 and 9.0015 MHz), one each for lower and upper side-band.
The output of BFO is applied to product detector for reception of CW and SSB signals. |
Rs 150
US$ 3 | Construction | |
| 17 | 220V Live Wire Scanner
This simple circuit lets you scan a 220V live wire. The clock input of the IC is connected to a wire, which acts as the sensor. Here, we have used 10cm length of 22SWG wire as the sensor. |
US$ 1
Rs 50 | Circuit Idea | |
| 18 | -30V to +30V Regulated Power Supply
This dual power supply circuit provides 1A regulated supply from -30 volts to +30 volts. |
US$ 1
Rs 50 | Circuit Idea | |
| 19 | 360 Hi-Fi Stereo Power Amplifier
This hi-fi amplifier circuit produces 360W PMPO into a 4-ohm load. |
US$ 1
Rs 50 | Circuit Idea | |
| 20 | 3-Band Radio Receiver Using BEL 700 IC
This monolithic integrated circuit is designed for use in AM(including shortwave bands), with an IC which ensures uniform sensitivity over a wide supply of voltage range of 2.7V to 12V. |
Rs 150
US$ 3 | Construction | |
| 21 | 3-Colour Moving Curtain Display Name Plate
In this circuit, moving curtain effect in LEDs name plate display is shown. All letters of the name plate are lit sequentially from left to right in red colour first. When all letters have been lit in
red colour, the colour of the letters changes to yellow from left to right. When all letters have been lit in yellow colour, the colour of letters changes to green from left to right. When all letters have been lit in green colour, the letters start switching off from left to right. |
US$ 1
Rs 50 | Circuit Idea | |
| 22 | 3D Surround Sound System
Surround sound is the concept of expanding the spatial imaging of audio playback from one dimension (mono/left-right) to two or three dimensions |
Rs 150
US$ 3 | Construction | |
| 23 | 3V PC Adaptor
Plug this circuit into the available USB output port of your PC to get 50mA, 3V DC. So it can be used to recharge, for instance, two NiCd cells (1.2Vx2) of a portable music player system. |
US$ 1
Rs 50 | Circuit Idea | |
| 24 | 40-Metre CW Transmitter
This 7.0-7.1MHz (40-metre) amateur radio band low-power transmitter using two FETs and two bipolar transistors produces sufficient power of about 1 watt for CW operation, to provide adequate coverage if propagation conditions are favourable. |
US$ 1
Rs 50 | Circuit Idea | |
| 25 | 40W +40W Auto-Reverse Stereo Cassette Player
This circuit reverses the direction of movement of an audio cassette tape automatically after the side has been fully played, thus enabling continuous play of music. |
US$ 1
Rs 50 | Circuit Idea | |
