How to Make a Burglar Alarm Circuit for Your Home Security?

These days home security systems are given great importance everywhere. However these security automation systems are very expensive to implement. Here I will help you to make a simple IR security system by your own using an Infrared-photodiode pair.

Earlier we had already published another intruder alarm circuit diagram which was based on LASER and LDR. However it has a probability that the thief might see the LASER beam and avoid theft alarm easily. This simple circuit will give you an insight into how do burglar alarms work.

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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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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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PWM LED Dimmer/ Brightness Control by 555 Timer With Video Simulation

How to change the brightness of a LED? Whether led lights are dimmable? Is it possible to adjust the brightness of LEDs? LED is basically a diode, when the forward voltage exceeds 0.7 volt, it starts to glow, and if the forward voltage is less than 0.7 volt, it will be in the OFF state. What happens if we are providing a high voltage to the LED so as to increase the brightness?

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Top 10 Science fair Electronics projects for School students

Are you looking for simple electronics projects for your school projects? Your search ends here…! Nowadays every school student wish to have a good science project for their science exhibition. Today www.circuitsgallery.com presents you the top ten science fair projects collected from our published circuits database. Here we are going to give you school project ideas (science experiment ideas) along with details and circuits.

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Simple Over Voltage Protection Circuit: High Voltage Cut Off

Voltage fluctuation is a serious issue in every home. Due to some reasons our supply voltage may rise above 110V or 230V. Flow of this high electricity may lead to the damage of our home electrical devices. Have you thought how electrical protection is possible via a simple over voltage protection circuit? Here CG comes with an interesting over voltage protection device to protect your electrical appliances from getting damaged. Zener diode voltage regulator is the main part of this high voltage cut off circuit. You can implement this over voltage protection relay circuit in your home as a high voltage regulator.

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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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Simple fire alarm- thermistor circuit diagram

Here i-St@r comes with a simple and automatic fire alarm and detection system. This fire detection alarm circuit is based on thermistor. What is a thermistor? A thermistor is nothing but a variable resistor whose resistance increases as temperature decreases. Fire detection is simply possible via this low-cost alarm circuit.A simple potential divider arrangement using thermistor is capable of sensing the temperature (presence of fire) and alerting us with a warning signal. This is suitable for your home security systems. Also school students can do this fire detector circuit as their high school science fair projects. Here I will explain in detail about fire alarm circuit wiring with animation/ simulation of fire alarm.

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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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Transformer less AC to DC power supply circuit using dropping capacitor

Production of low voltage DC power supply from AC power is the most important problem faced by many electronics developers and hobbyists. The straight forward technique is the use of a step down transformer to reduce the 230 V or 110V AC to a preferred level of low voltage AC. But i-St@r comes with the most appropriate method to create a low cost power supply by avoiding the use of bulky transformer.Yes, you can construct power supply for your development without a transformer. This circuit is so simple and it uses a voltage dropping capacitor in series with the phase line. Transformer less power supply is also called as capacitor power supply. It can generate 5V, 6V, 12V 150mA from 230V or 110V AC by using appropriate zener diodes. See the design below.

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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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