Buy Circuits Online from CircuitsGallery

With the continuous support we are getting from our readers in the past years, we the i-St@rGroup team are thinking of introducing a new service.

It is our pleasure to announce that we have started an online STORE for buying electronics circuits and projects. 

It includes assembled electronics circuits, school projects ,college projects, electronics components, PCBs etc. at a reasonable rate and minimum home delivery time.

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Simple Emergency Light Circuit with Automatic Charger

Some of our readers requested for Emergency circuit with charge controller. Here I'm presenting  such kind of a circuit diagram with automatic charging.

It is very easy to implement on your home and work areas.Our circuit is capable of turns on the light automatically when power failure occurs and turn off if main supply is return.

LEDs are used as emergency light bulbs in this system, The important specialty of this Emergency circuit is an automatic charge controller which recharge the battery if the voltage is below the threshold level and cut off the charging supply to the battery, if the voltage reach at the pre-set level, two LEDs are used to indicates the of presents of main power and activation of charger.

This circuit mainly focus to lead acid battery life, in this circuit design we limit the maximum charging voltage is 13.8V as per lead acid battery manufacturers.

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Automatic Rain Sensing Wiper System using 555 Timer

Have you seen Audi, Lexus or Ford rain sensing wipers and wondered how they work in these vehicles? They are handled by sensors at the center of the windscreen which detects rain water and turns on the wiper motor. Here is the working of rain sensitive wipers with circuit schematic. The main component of this circuit is a 555 timer IC that works in monostable mode. Two metal sheets fixed at a small distance apart are used as rain detector sensors. From the working of a monostable 555 timer, a negative voltage on the trigger pin will cause a high output. So when it rains, trigger pin gets a negative voltage. Output of one shot 555 (monostable) is connected to a relay through a transistor. The transistor acts as a switch for the relay to turn ON the wiper motor during rain.

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555 Touch Sensor

How to make a touch sensor? Here is a simple DIY touch sensor circuit diagram using 555 timer monostable mode. Touch switch is only a conducting metal sheet that acts as touch sensor. The 555 touch switch is not a touch capacitive sensor; it is only a metal touch sensor button. Using this you can turn on and off devices by single touch. Here we are using a JK flip flop IC 7476 that is connected as T-flip flop. The output of T-flip flop is connected to the base of transistor to turn ON the relay so as to control high current electrical devices such as fan, motor, lamps etc.

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Simple Solar Table Lamp Circuit for your Home

Solar energy has now become a popular alternative for the production of electricity. Here is a green energy project for school students on how to make solar lamps for your home. The main component of this simple solar lamp circuit is a small solar panel and a battery using rechargeable cells. This battery can light the white LED’s and provide sufficient amount of light in your room for a longer period.

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Automatic Temperature Controlled Fan Circuit using Thermistor

This is a simple automatic temperature controlled fan circuit using NTC thermistor. The main components of this temp control fan circuit is a negative temperature coefficient thermistor (NTC) which detects the temperature, a comparator which is used to compare the preset temperature value and a relay circuit to drive the fan. Power supply for this circuit is given by a step down transformer and a bridge rectifier. A filtering capacitor is used to get perfect DC. We will be posting a circuit on how to control fan speed as speed control of fan is not discussed in this thermistor applications circuit.

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How to make a circuit of Automatic Street Light control system?

Automatic street light system is very common nowadays as it provides intelligent street lighting mechanism. It provides light automatically during night without any human interference. These energy saving street lights make use of incandescent lamps instead of LEDs.

So here I will teach you how to make an electronic circuit for street light automation. The heart of this circuit is a LDR (Light Depended Resistor) which is connected as a potential divider with a 56K resistor. The drop across LDR is used for switching the transistor. Solar led street lighting systems are the advanced versions of this ordinary automatic street light controller.

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LED 12v Emergency Light Circuit Diagram

Here is a simple LED emergency light circuit that you can implement for home lighting during power failures. We know that LED bulbs consume very less power and hence they have a much longer life. This LED lighting circuit design is intended to light automatically during main power failures. So here we are going to help you with the building of cheap emergency lights. The main part of this led light schematic is a relay, which automatically connects DC voltage to the battery when main power is present and connect LEDs to the battery in the absence of main power supply.

Upon request from our readers, we have integrated this with an automatic battery charger circuit. See our updated  emergency with automatic charge controller.

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Remote Controlled DC Motor for Toy Car Circuit Diagram

This is a simple hobby circuit of a remote controlled toy car. The main component used here is the IR sensor circuit consisting of TSOP. Using a TSOP IR receiver we can start and stop the DC motor vehicle. However this circuit has a small disadvantage that it can’t control the speed of DC car motor, rather it ON and OFF the small dc motors. Thus it is suitable for electronics beginners only.

Once it is ON, the motor runs with a constant speed. No speed control circuits are discussed here. The advanced version of this circuit with PWM speed controller will be posted soon. You must need a regulated power supply of 5 volt to do this one because TSOP requires 5v for its operation. Below is the circuit diagram and working of remote controlled dc motor for car using T sop infrared detector circuit.

Note: TSOP voltage should not exceed 5V.

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Water level sensor circuit: projects for school students

I have posted wide varieties of small electronic projects on water level sensor  in Circuits Gallery. This is another project for school students to detect the water level inside a water tank or any other water reservoir. We can call this as a ‘liquid level sensor’, because this circuit is able to sense the presence and absence of liquid in a tank.

This school electronic project is built around BC548 transistors and a 7432 OR gate IC. This water alarm will produce a beep sound when the water goes below a specified level (h1) or when the water overflows. This is one of the home science experiments that can be implemented as science projects for high school students.

You may also like to have a look at our other science experiments like automatic water tank level controller and numeric water level indicator. I have also published an article to detect overflow of water using alarm.

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Home security alarm system circuit diagram

Have you ever thought about implementing your own home security alarm systems? It's one of the simplest and interesting circuits for electronic beginners. Our new home security equipment uses a LDR (Light Depended Resistor) to detect security problems. Theft attempt and other security threats can be controlled by using this simple circuit to improve your security systems. This is also best suited for school students for their high school science projects.

To implement this alarm system for home, you have to provide an optical path (with LASER beams) around your home. The LASER path is made possible with one LASER torch and 3 mirror arrangements which encloses the whole area. Please refer the project arrangement section below to make this optical (light) path. We have explained about home security system in detail with animation/ simulation.

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Low water level indicator alarm circuit for Water tank

Most of the time we wish to have a water low level alarm (liquid level alarm) circuit to know if the amount of water inside the tank has decreased in order to switch ON the water pump set. Don’t worry about that, we can implement a simple water low level indicator sensor alarm circuit for your home or office with the help of liquid level probes. Our water level sensor alarm detects the fluid level using a transistor switching circuit. We have already discussed about different types of fluid level alarms and water tank level indicators, they are mainly to detect overflow from the water tank. But this one indicates that the tank is near to be emptied.

(This circuit is posted as per the request from one of our reader MR. Ramz)

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UM66 based Water tank over flow musical alarm circuit

This is a simple home automation project based on UM66 melody generator IC. Water tank overflow musical alarm is best suited for science projects in schools. In one of our previous article we had already discussed about another liquid level sensor alarm circuit that produces a beep sound, but this circuit gives a melody sound whenever water in the tank over flows.

Below is the circuit schematic which produces a melody tone whenever the water tank completely filled by water. This circuit also employs transistor switching technique. The advantage of this circuit project is that it uses UM66 musical IC which is capable of producing melody sound when it detects the presence of water and saves water from being wasted.

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UM66 Musical door bell alarm circuit- Melody generator

This circuit is suitable for musical bell in doors, home security alarm systems,  burglar alarms etc. The main part of this alarm circuit is an UM66, which is a melody generator IC.  It is a very small IC that almost looks like a transistor, it has an inbuilt tone and a beat generator. This IC is programmed to generate certain frequencies.When power is turned on, the melody generator is reset and melody begins from the first note.

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Clap Switch Circuit using NE555 timer IC

Here is one of the interesting 555 timer circuits to trick your friends while studying electronics in schools. Clap switch circuit is the local name of sound controlled flip flops. This sound controlled light can also be used as sound detection sensors. Flip flops are single bit storage elements. NE555 timer IC is the important part of this circuit. Here NE555 is configured in monostable multivibrator mode and is connected to the clock input of a 7474 D flip flop. The flip flop is connected to work in 'Toggle' mode. The relay circuit is energized by a 7474 flip flop. You can connect any electrical/electronic device at the output instead of the electrical bulb used here. Below is the electronic circuit diagram and working of the clap light switch.

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Remote Control Light Circuit Diagram Using 555 Timer

You may wonder if it is possible to control a light using a remote controller. In this article CircuitsGallery presenting an interesting DIY circuit that helps you to turn ON and OFF a lamp with a remote controller.

Here we have made use TSOP, an IR receiver, which detects the IR rays from the remote. NE555 is the next important part which produces a clock pulse for toggling the D flip flop.

The relay helps to connect any electrical devises to the circuit and you can control any electrical equipment not only a light.

You must need regulated power supply of 5 volt to do this circuit because TSOP require 5v. Its voltage should not exceed 5V.

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