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. A simple scoring game circuit that can be used for all occasions when a dice is needed.The circuit is based on a NE555 timer,a 74LS192 counter,a74LS247 decoder and a & segment LED display.The timer IC1 will produce the clock for the counter IC(IC2) whose frequency is determined by R1 and C2.When S2 is pressed
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
A simple Light to Frequency Converter Introduction. Here is the circuit diagram of a effective light to frequency converter circuit that can be used for variety of applications such as light intensity measurement,fun etc. The circuit is based on TLC555, the CMOS version of famous timer IC NE 555. A photo diode is used for
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
Transformerless power supply Circuit Description Here is a low cost and simple circuit that can be used to power up small electronics devices. The power is directly tapped from the mains via resistor R1. D1 rectifies the voltage and C1 and C2 are used to filter the output. The zener diode D2 will regulate the
Remote control tester Circuit Description This is a simple remote controller tester circuit based on infrared sensor IC TSOP 1738. When the IR waves fall on the sensor it output changes to low state. This makes the transistor Q1 (BC558) ON and LED will blink according to the code contained in the signal. So for
12 Watts Transistor Amplifier Circuit Description The circuit shown below is not at all expensive as the amplifier contains only an op-amp and four transistors (easily available from your electronics junk box). Here the op-amp used is uA 741 which produces the required gain. The four transistors are wired as complementary Darlington’s which produces the
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
6 Volt Regulator using IC 7806 Description Here is the elementary 6V 1A power supply circuit using 7806 IC. The 7806 three-terminal positive voltage regulator is available in the TO-220/D-PAK package making them useful in a wide range of applications. 7806Â employs internal current limiting, thermal shut down and safe operating area protection, making it
In this project, let’s build a simple Remote controlled switch for appliance controlling. If you know basic concepts of electronics, this circuit is pretty easy to build and test. The core of this circuit are two IC’s – which are infra red sensor IC’s – TSOP 1738. A couple of transistors and associated components complete
