Voltage fluctuations in the mains are very common phenomenon. These fluctuations can cause heavy damage to costly electronics and electrical gadgets operating for long period of time. For such purpose, an automatic stabilizer is used which is usually quite expensive. A costly voltage stabilizer can be replaced with this low-cost Solid-state Voltage
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Indicator with High Voltage Cutout circuit. It can also be used to convert a manual stabilizer into an automatic one. It performs three functions in different conditions. X1 is a voltage step-down transformer that steps down 220V AC to 18V. This voltage is filtered and rectified by C1 and D1 respectively. As the output of the transformer is not well filtered and regulated, the output will be proportional to the input. VR1 is adjusted to operate the relay at a particular voltage higher than the output voltage of the transformer at normal mains level. So, when the mains voltage increases, the output of the transformer also increases. Zener diode ZD2 starts conducting and provides bias to T1 which starts conducting. This in turn energizes the relay and light up the RED LED (LED1), to indicate a high voltage. Diode D6 provides protection to the relay against induced voltages. IC LM741 (IC1) forms the heart of the normal and low voltage indicating circuitry. The potential of the non inverting input serves as the reference voltage across zener diode ZD4. Variable resistor VR3 set the DC gain of IC1. LED D5 is connected between the output (pin 6) and the positive supply. R5 limit the current going to diode LED5. Under normal conditions, the voltage as the inverting input will be higher than at the non-inverting input. So the output will be low, ad LED5 will remaining glowing. But, when the mains voltage drops, the voltage at...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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