A regulated 5 volt DC supply is essential for powering micro-controller and TTL based circuits. The output of most wall-warts and adapters is to rippled and impure for use in digital circuits. Lets build an inexpensive power supply using some discrete components and a fixed voltage regulator IC. The circuit consists of three main blocks, the recti
Click here to download the full size of the above Circuit.
fier, filter and regulator. The rectifier is used to transform the mains AC voltage to a suitable DC voltage. The output of the rectifier is however an impure DC signal so we use a filter to clean the signal and finally a regulator to deliver precisely 5 volts, irrespective of the load connected to the output. It consists of a transformer and a diode bridge. The diodes are standard silicon 1N4007 diodes. We have chosen a 12V transformer because the regulator IC needs at-least 7. 5V of input voltage to function properly. We use a pi-filter here. The two 220 µF capacitors and resistor form the filter. Pi-filters are great for light load applications like digital circuits. Be sure to check the polarity of the capacitors before connecting them. The resistor shown above is one rated to dissipate up-to 5W of power across it. You may use smaller 3W resistors, but availability may be an issue. Don`t use the tiny 0. 25 W or 0. 5W ones though. The voltage is regulated by three terminal voltage regulator IC LM7805. This regulator provides stable 5V DC output against large fluctuations in input voltage and load. It also has internal protection circuits which `brownout` the device when overloaded. To decide the pin-outs, hold the regulator with its face towards you and legs pointing upward, the pin to the right is the input, middle pin is ground and left most pin is output. A 6. 3mm or 3. 5mm female mono TRS connector (tip, ring,...
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: