Description. Here is the circuit diagram of a simple stepper motor controller using only elementary parts. The driver circuit uses, four transistor (SL100) to drive the motor windings, two NOT gates and one XOR gate to decode the two bit control logic to drive the four windings of the motor. The diodes D1 to D4 […]
Description. Here is the circuit diagram of the simplest FM transmitter using a transistor. Great performance or range is not guaranteed here, because this is an elementary design. General purpose radio frequency transistor BF 494 (Q1) is used here for obtaining FM modulation. A condenser mic is used here to pickup the sound. The condenser
Description. Here is a straight forward, yet effective digital temperature controller that can be used with temperature control systems. The circuit uses IC LM 35 (IC3) to as the temperature sensor. The output of LM 35 is given to the IC ADC 0804 (IC4) which converts the analog output of the LM 35 to digital
Description. Here is the circuit diagram of a simple yet interesting mini organ based on UJT 2N 4891 (Q1). You can produce the desired sound by pressing each pushbuttons. You have also the option to set each push button to produce the desired tune you want. The circuit is based on a UJT oscillator who’s
Introduction. Here is low cost circuit that can be used for implementing a warning light on the top of tall structures as a warning for low flying aircrafts. Usually such lights are just stay glow type. Here our light is a flashing type, and surely this will draw more attention and of course add more
Description. Almost all liquidator type mosquito repellers are rated 5Watts. It is a pretty energy consuming game when these repellers are operated through out the night. Even though these liquidators are switched ON and OFF in discrete intervals there will be no considerable loss in the effectiveness, and more over there will be a great
Description. Here is the circuit diagram of an effective and super fast Ni-Cd battery charger circuit.The circuit is based on the IC MAX 712. The circuit is designed to fast charge a Ni-Cd battery at 3oomA. After the fast charging is completed the circuit charges the battery in trickle charging mode at 15 mA. Here
With this cool cat/dog repeller circuit you could chase the cats off from any where you want. In fact, I designed this circuit to chase my cat from my computer table. Most of the animals like cats respond violently to ultrasonic sound and in fact it’s the best way to chase them off. This principle
In this tutorial, we have explained how to build a DIY (Do It Yourself) Infrared Motion Detector Circuit using 555 Timer IC, IR Diode, 2 comparator IC’s and other associated components. An Infrared Motion Detector circuit can be designed in different ways using different sort of components. This one is a low cost, easy to
Description. When there is a fire breakout in the room the temperature increases. This ultra compact and low cost fire alarm senses fire breakout based on this fact. Transistor BC177 (Q1) is used as the fire sensor here. When the temperature increases the leakage current of this transistor also increases. The circuit is designed so
Description. Here is a simple rain alarm circuit that produces an audible alarm when ever rain falls. The rain detector circuit is based on two transistors (Q1 & Q2) and a NE555IC (IC1). The two transistors are wired as a switch which goes on when the base of Q1 is shorted to the positive of
Description. Here’s a low cost radio circuit that can be used to listen to the radio conversations between aircrafts. The radio circuit based on transistor 2N918 and diode 1N82 receives in the 220Mhz to 400Mhz range. Capacitor C1 and inductor L1 forms the tank circuit for tuning. Diode D1 performs the detection. Transistor T1 performs
Description. This is a modification of the circuit Simple Lamp Dimmer/Fan Regulator previously posted here. The working of the circuit is same as that of the previous, but in addition a snubber circuit consisting of resistor R4 and capacitor C3 is included to improve the performance of the triac T1. A fuse is also included
 Description. Here is a versatile night light circuit that can be used in two modes. The dimmer mode and a flashing mode. The circuit is based on dual opamp LM 358 and associated components. The first opamp IC1a is wired as a pulse generator and the second opamp is wired as a comparator. When the
Description. A straight forward circuit diagram of a 3W stereo amplifier circuit using MAX 7910 IC is given here. This circuit is ideal for small power audio applications like portable CD players or radio sets. The circuit is designed strictly as per the datasheet and found to be working great. The MAX9710Â a stereo audio
Simple Battery Level Indicator Description Here is a easy to build low battery level indicator circuit that produces a visible indication by flashing a LED when the battery voltage drops below a predetermined voltage.The circuit is based on Panasonic’s IC MN13811G  and a efficient flasher based on transistors Q1&Q2.Here when the battery voltage drops below
A Simple Light activated switch Description. This is the circuit diagram of a light activated switch based on National Semiconductors comparator IC LM 311 and a LDR. The circuit is based on a voltage comparator circuit wired around IC 1.The non inverting in put of IC1 is given with a reference voltage of 6V using
Audio Level Meter Description A simple and low cost audio level meter circuit that can be used to measure the audio level of your sound source.This circuit is a valuable tool for those who are interested in audio circuits. The circuit is designed with a flat frequency response in the range of 20Hz to 50Khz.
Simple AM Transmitter Transmitters are devices that are capable of transmitting audio as radio waves from an audio device. There are two types of transmitters; FM & AM. We have many posts on FM transmitters, so we decided to make one on AM transmitter. AM transmitters create radio waves using Amplitude Modulation (that’s why AM).
Single chip FM transmitter An FM transmitter is a device that can transmit audio from an audio device as a radio signal. Doing so allows the audio to be picked up and played by an FM radio in the transmitter’s range. The FM (frequency modulation) device allows the waves to move in predefined frequencies so
Low Cost 150 Watt Amplifier Circuit In this project, we’re building a simple 150 watt amplifier circuit. Description This is the cheapest 150 Watt amplifier circuit you can make,I think.Based on two Darlington power transistors TIP 142 and TIP 147 ,this circuit can deliver a blasting 150 W Rms to a 4 Ohm speaker.Enough for
100 Watt Inverter-Circuit Diagram, Parts List & design Tips Inverters are devices that convert DC input supply to AC (alternating current). They are also called power inverters. Power inverters have numerous applications in power electronics field. It is used in various applications like induction heating, UPS, controlling electric motors, refrigerators, solar and many more. A
Hi Fi Amplifier Circuit – 2X12 Watts HiFi or High fidelity is a term used to indicate equipment that reproduces a high quality of sound. The highlight of Hi-Fi equipment is inaudible noise or distortions and a natural frequency response. Hifi amplifiers are known to create sounds with utmost clarity so it is a dream of all
Mini Amplifier Circuit Audio amplifiers are electronic amplifiers that are used to amplify weak audio signals from an input like a mic to high amplitude signals to be reproduced through loudspeakers. This is a very simple hobby project suitable for beginners. This homemade mini amplifier circuit is suitable to hone your soldering skills and show off
USB LED Lamp Circuit Description Here is a simple USB powered lamp that can be used to light your desktop during power failures. The circuit operates from the 5 Volt available from the USB port. The 5V from the USB port is passed through current limiting resistor R2 and transistor Q1. The base of transistor
