Basic Electronics/Electrical Projects & Kits

Get our latest collection of basic electronics projects here -- all tested and reviewed for use in mini projects and main projects or even just as hobbyist projects!
Cordless FM MIC Save Rs. 50.00
Rs. 200.00
Rs. 150.00

Cordless FM MIC

Cordless FM MIC

by KNS Pvt Ltd
Save Rs. 50.00
Rs. 200.00
Rs. 150.00

Summary

The Cordless FM Mic can be used as an FM transmitter. The frequency transmitted by the circuit is FM modulated and hence the voice at condenser microphone can be listened to through a standard FM receiver.

Learning

Things which you can learn:

*Concepts related to FM modulation and transmission.
*Application of NPN transistors as signal amplifiers.
*Application of the condenser mic as an input device.

Product Description

Build a simple circuit which can be used as a one-way walkie talkie. Use this kit to transmit your voice over FM and receive the sound in a standard FM receiver.

Working

The circuit of the Cordless FM Mic consists of a high-frequency air core coil (L1) with six closely wound turns of 25 SWG enameled copper wire on 4 mm diameter air former. The range of this transmitter can be enhanced by connecting a 30-60cm long wire as an antenna and changing the value of the 0.0015 micro Farad capacitor to up to 33 Pico Farad.

The range and transmitted frequency can be changed by increasing or decreasing the length of wire which is connected to a collector of NPN transistor 2N2369 (T2)via a capacitor. NPN transistor BC548 (T1) works as a condenser mic amplifier and T2 works as an FM oscillator and modulator by the help of other passive components. The main advantage of this transmitter is that it works off a 3V battery which can be easily obtained from two AA size pencil batteries.

Click To View Circuit Diagram

Click here to Download PDF

Noise Level Alarm Save Rs. 50.00
Rs. 300.00
Rs. 250.00

Noise Level Alarm

Noise Level Alarm

by KNS Pvt Ltd
Save Rs. 50.00
Rs. 300.00
Rs. 250.00

Summary

Noise pollution can cause hearing loss, hypertension, heart disease, annoyance, sleep disturbance and decreased performance in schools. Build this kit and set the threshold level for the noise and get informed whenever the sound gets exceeded the desired limit and thus prevent damage to the health.

Learning

Noise level monitoring gives a brief hands on concept of cascaded and three stage amplifiers in analog electronics and amplifying a very small signal with high gain transistors

Things which you can learn:
1. Cascaded three stage amplifier
2. Analog electronics
3. Gain in transistors
4. Condensor mic

Product Description

Noise is a serious environmental problem that affects us in our daily life. There is scientific evidence supporting that noise exposure can cause hearing loss, hypertension, heart disease, annoyance, sleep disturbance and decreased performance in schools. Sound-level indicators like the one presented here can help address this problem. This sound-level indicator monitors the sound level and indicates through an LED when the level is above the preset value.

Working

The sound is captured by microphone MIC1 and amplified by first stage high-gain transistor T1. Trimmer potentiometer VR1 is used to adjust the threshold level. the signal is amplified again with second-stage transistor T2. This amplified signal is rectified by diode D1 and the charge is stored in capacitor C10. Diode D1 should preferably be a small-signal Schottky diode such as BAT81, BAT82, BAT83, BAT85 or better. You can use 1N4148 and 1N914 also but the signal from the input should be stronger.

Click To View Circuit Diagram

Click here to Download PDF

Sound Operated Timer

Sound Operated Timer

by KNS Pvt Ltd
Rs. 250.00

Summary

The Sound Operated Timer is a multi-purpose electronic switch that can be used in a number of applications. The switch gets activated by the sound of a clap when clapping is done in front of a condenser mike. This turns on the appliance connected to the relay for a specified time period, after which it is automatically turned off. No. of ICs used: 1.

Product Description

The heart of the Sound Operated Timer is the NE555 timer IC (IC1) which is being operated in the monostable mode. The condenser mike converts the incoming sound signal to electrical variations that are amplified by transistor BC149. Resistors (R1-R4) and a capacitor (C1) provides proper biasing conditions for working of T1 in the active region. The amplified signals are effectively passed by capacitor C2 to trigger input pin (pin2) of IC1. This results in momentarily pulling pin2 to a low level whenever you clap in front of the mike. IC1 generated a rectangular pulse of time duration Tm at its output pin (pin3). This time duration is decided by values of preset VR1, resistors R7, R8 and capacitor C3. Thus relay RL1 at output remains energized for this specific time duration. Rotating the preset VR1 clockwise will increase this time while rotating it in an anti-clockwise manner will result in opposite effect. Diodes D1 and D2 are used as free wheeling diodes and help in proper functioning of the relay.

Learning

Application of the NE555 timer in the monostable mode.
Use of relays for appliance switching.

Voice Recording and Playback System Save Rs. 250.00
Rs. 1,300.00
Rs. 1,050.00

Voice Recording and Playback System

Voice Recording and Playback System

by KNS Pvt Ltd
Save Rs. 250.00
Rs. 1,300.00
Rs. 1,050.00

Summary

The Voice Recording and Playback System enables recording of upto 8 different messages. In the playback mode, the circuit plays recorded message either randomly or in a sequential fashion. Build the project and enjoy listening to secret talks of your friends.!!

Learning

Things which you can learn:

*Application of the voice processor(aPR33A)
*Inbuilt low-power audio amplifier
*Concepts and implementation of ADC and DAC

Product Description

Buid a cool voice recording with playback system and become a SPY agent like the famous 007 james bond.


To record the voice ,Close slide switch CONN4 to make pin 12 low, thereafter, hold S9-S14 to record corresponding voice messages. LED2 glows to indicate with beep to indicate recording continues.
For playback of any device status, open the slide switch CONN4 and press the corresponding switch S2 to S7, the recorded audio can be heard through speaker connected to CONN2.

 

Click here to Download PDF