The design presented here is a little bit unusual in its arrangement, but offers some advantages over the usual designs that I will explain in the following paragraphs. First, let`s start from the basics: A linear power supply has a transformer that steps down the line voltage to some voltage that is higher than what will be required at the regulated output. Then a rectifier and
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a filter capacitor transform the low voltage AC into a moderately filtered DC that still is unregulated and has some ripple. Finally, a regulating circuit "burns off" the excess voltage, leaving only the exact amount desired at the output, typically 13. 8V for communication equipment. One typical mistake made by many amateur designers is using a transformer that has a voltage that`s too low for the combination of rectifier, filter and regulator used. The situation is this: You need 13. 8V at the output at all times. Your regulator eats up a certain minimum voltage, which depends on its design. Many regulators need at least 2V across them, so you need 15. 8V minimum at the worst time across the filter capacitor. This is the voltage at the minimum point of the ripple waveform, but the capacitor needs to be charged to the maximum of this ripple voltage. So, the size of the capacitor defines how much additional voltage you need for this. A 60000uF capacitor, used at 20A, and discharging during almost a half cycle at 50Hz (10ms), will drop the voltage by almost 3. 3V. So, you need to charge the capacitor to at least 19. 2V under the worst conditions! If you are using a bridge rectifier made from silicon diodes, which loose about 1. 2V each at peak current, then you end up having two diodes conducting at the time of charging the capacitor, dropping a total of 2. 4V. So, the transformer needs to develop 21. 6V peak voltage. This...
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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