Certain part of this circuit is directly connected to AC mains. Therefore, do not touch whilst in operation. Disclaimer Please take the greatest of care in handling AC mains supply while constructing this project. If you have no knowledge of mains wiring or unfamiliar with household mains supply, PLEASE DO NOT ATTEMPT CONSTRUCTION. I take
Click here to download the full size of the above Circuit.
no responsibility in any personal injury or loss of life or properties suffered by any person while undertaking the construction of this project or using the end product by following my instructions. Usually a soldering iron takes a couple of minutes to get adequately heated up to melt the solder, after which the heat generated is much above the requirement and is wasted. Moreover, excessive heat decreases the life of the bit and the element, causing serious damage to the components. Once the main is switched on, an approximate 15v drop of the positive half cycle across R5 is detected and supplied to Q1 (SL100 or D313), which acts as a voltage regulator. Zener diode D2 together with diode D3 (yellow LED) stabilizes the emitter voltage of Q1 at 13. 2Vdc, which is then delivered to the relay circuit built around Q2 and C3. Capacitor C3 charges through the base-emitter path of Q2 and causes the relay to actuate, which in turn allows both the half cycles of the AC mains to flow through diode D6 and R5 to the load to heat it up at a normal rate. After a certain lapse of time (about 2 minutes preset) C3 saturates and Q2 stops conducting through the relay, thus switching on series diode D5 to allow only half of the Ac cycle through the load. After switching off the system, C3 discharges very slowly through R2 and R3. Before C3 gets completely discharged, if the power is switched on again, C3 takes a shorter time to reach the...
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.....
characters left: