You can use this Simple Alarm to protect the door or Window. It gives a loud beep and switch on the room light when an intruder/burglar attempts to breaks the door lock. The alarm functions only after 5 minutes to confuse the intruder. Working of this burglar alarm circuit is simple. IC1 is used to…

 This circuit can protect your Electronic devices like TV from inrush current. Very high spikes can develop at power on due to sparking in the switch and more serious effects occur when power resumes after a power failure due to high magnetic field in the distribution transformer. When we keep the TV in standby mode through…

This circuit can sense the overload condition and breaks the power if the load increases above the set point. It is an ideal circuit to protect Uninterrupted Power Supply devices like Inverter.Let us see its working …The Optocoupler MCT2E and the Resistor R3 (1 Ohm 10 Watts) will do the trick. The Optocoupler has an LED and a Phototransistor inside with connecting leads. The LED of MCT2E is connected parallel to the resistor R3 with a current limiter R2 for the LED. The phototransistor of Optocoupler is connected to the transformer derived 9 volt DC through the current limiter R1. The load is connected through the Common and NC contacts of the relay. So it will work normally at power on.

 This light triggered circuit can be used to turn on / off a load such as lamp through the IR rays from a remote or light from a torch. This is an ideal circuit to switch on / off the room light using TV remote while watching the TV .The circuit uses a Phototransistor and…

Everyone must be familiar with the term – Switched Mode Power Supply or SMPS. Yes, they are used in every personal computer. In fact, the Switched Mode Power Supply is widely used with many other devices. Once it is understood that what SMPS actually is, its countless applications can be easily imagined.  An SMPS is used for converting the electronic power supply efficiently. Any SMPS has some storage components which store electrical energy to supply to the load device and some switching components which turn on and off at high frequencies charging and discharging the storage components.

The electronic devices are very sensitive to the fluctuations in the power fed to them. This problem can be solved by using regulated power supply for them. This [[wysiwyg_imageupload::]]project about power supply circuit is equipped with an adjustable voltage regulator to adjust the output in accordance with the requirement. Adjustable voltage regulators have both line and load regulation which is better than standard fixed regulators. The circuit is made using following active and passive electronic components:  1.      Bridge Rectifier2.      Resistors3.      Capacitors 4.      Variable Resistors.5.      Linear Voltage Regulator IC

Voltage regulator is a device which provides fix output voltage in spite of the variable input voltage supplied. It is a three terminal device. Voltage [[wysiwyg_imageupload::]]regulator basically comes in two different series: 78XX and 79XX. Voltage regulator under 78XX series are designed for positive inputs i.e. if while   79XX series are designed for negative inputs.

The circuit which is shown here is too easy circuit. In this circuit IC1 is mounted in a unusual mode. At the time when power resumes, pin 2 of IC1 which is through capacitor C1 is grounded goes low and pin 3 of same IC switches to high. In turn of this pin 4 of IC1 which is a reset pin switches to high state for approximately 10 seconds. When the voltage at C1 reaches to 2/3 of the supplied voltage, capacitor starts discharging and output switches to low, grounding the pin 4 which is a reset pin and hence the fell circuit move out of action.

This capacitor power supply can deliver 12 volt DC and 100 mA current to power low current devices. It is provided with surge protection and is totally isolated from mains supply using two capacitors in the phase and neutral lines. So the connected device is safe even if the phase and neutral lines changes.  Transformer…

Transformer is an electrical device which works on the principle of Faraday’s law of electromagnetism used to step up or step down the input [[wysiwyg_imageupload::]]voltage.Transformers are of different types for example: Power transformers, Current Transformers, Potential Transformers, Pulse Transformer, RF Transformer and Audio transformers. The most common application of Current transformer is to reduce the current and provide galvanic isolation in current sensing devices. Some typical examples include SMPS, motor control and electronic lightning ballasts.Some of you would know how a current transformer works. Windings, Core, connections and other things which many of you have surely seen in the books or  in the diagrams.But how many of you have got the chance to see how actually it looks from inside. A small instrument but which works greater than its size. In today’s insight you will know how current transformers are made to work. 

In current technology scenario, monitoring of gases produced is very important. From home appliances such as air conditioners to electric chimneys and safety systems at industries monitoring of gases is very crucial. Gas sensors are very important part of such systems. Small like a nose, gas sensors spontaneously react to the gas present, thus keeping the system updated about any alterations that occur in the concentration of molecules at gaseous state.   Gas sensors are available in wide specifications depending on the sensitivity levels, type of gas to be sensed, physical dimensions and numerous other factors. This Insight covers a methane gas sensor that can sense gases such as ammonia which might get produced from methane. When a gas interacts with this sensor, it is first ionized into its constituents and is then adsorbed by the sensing element. This adsorption creates a potential difference on the element which is conveyed to the processor unit through output pins in form of current. What is this sensing element? Is it kept in some chamber or is kept exposed? How does it get current and how it is taken out? Let’s find out in this Insight!!! 

Shopping carts are handy, but all these carts require a push or pull to move around. How about we create a battery-operated cart that doesn’t require human efforts? In this project, we will design a mini motorized battery-powered shopping cart using four DC motors attached to four wheels, which can be controlled using a Bluetooth…

The proposed simple electronic spy Bug circuit is basically a high gain amplifier using the IC 741 as the heart of the circuit and also a couple of high gain output transistors. The IC 741 if configured as a non-inverting amplifier which performs the function of a pre-amplifier stage. The gain of this IC 741 preamplifier stage may be varied as desired, using the pot across its input and output pin outs. The gain setting is used to set the sensitivity of the amplifier and is set to maximum so that even low volume speech conversation may be picked through it. The mic at the input transforms sound vibrations into minute electrical pulses, which is further amplified by the IC 741 to suitable levels before applying it to the output amplifier stage consisting of a standard DARLINGTON stage. This Darlington stage is made using a couple of high gain transistors bc107A’s.

Many of us have modular kitchen which have chimney to extract smoke out so that smell of smoke will not fill in kitchen and avoids the harmful effects of smoke on furniture and kitchen utensils. But sometimes it happens we forget to switch on the chimney which results in smoke in kitchen and sometimes we forget to off the chimney leading to the wastage of electricity and money. So to solve this problem we have described a circuit which will switch on the fan automatically when smoke reaches to point and off the fan automatically.You can also use this circuit while soldering because as we know solder fumes are not good for health so it will on the fan to extract the smoke present in room leaving smoke free area.

  The simple pulse modulation technique called Pulse Amplitude Modulation (PAM) proved to be more power efficient than the PWM and consumes constant power for individual pulses like PPM. In PAM the amplitude of the individual pulses are varied according to the amplitude of the modulating signals. The PAM modulator and demodulator circuits simple compared…

In most of the homes the door bells are conventional ding-dong type. Most of us don’t like its sound. Due to mechanical moving parts with spring mechanism its long term durability is questionable. I had also one such door bell in my home. After a period of time its performance deteriorates and one time it becomes completely intolerable because of its noisy irritating sound.The new types of door bells available in market are bird sound door bell. They are costly and even I didn’t like it because of its high frequency and high volume sound output.     

There are many different types of robot projects that you might be aware of including the following: Remote-controlled robot (car type 3/4-wheeler) Joystick controlled robot Gesture controlled robot Smartphone (Bluetooth) controlled robot Obstacle avoidance robot Object follower robot Object finder robot Robotic Arm Pick and place robot And many more This article also describes a…

Ever wondered how are wires connected to a connector. How different number of wires are connected to segments of the connector? A connector aka jack for the earphone, headphone, microphone, like any other gadgets has an equally interesting chapter in the book s of engineering. It is among the cheapest part but not the technically inferior. It deserves its attention from the engineers for its design and quality.The connector plays an important part of tranferring signals from the device like mobile, laptops, music players etc to the earphone and the microphone and vice versa. Even a small problem may lead to an unplesant experience with the device. The connector has three contacts/segments/parts called the TIP, RING, and the Sleeve. Therefore it is also called the TRS connector.  

In the previous tutorials, it was  learnt that sequential circuits require memory elements to retain previous states of a digital system. The flip-flops and registers were then introduced as building blocks of memory in a sequential circuit. The registers are enough to store runtime data in small microcontrollers and ASICs. The complex computing systems require digital memory to not only store runtime information (as stored by registers in a microcontroller) but to store programs and data permanently within the digital system. So, they require dedicated memory either internal or external.