The Mini AV Test Box circuit is as simple and straight forward as I could design. It has three main sections that I split up in the schematic. The main devices used in the circuit are the 7805 +5v Regulator, 16F84A Microcontroller and 555 Timer. This is a very standard small scale power circuit that uses a 7805 to regulate the +9v input down to
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+5v. There are 47uF DC filtering capacitors on the input and output signals to/from the 7805. These help to keep the voltage level stable which the other digital devices in the circuit want to see. The first portion of functional circuitry is for creating the VGA output signals. The PIC does that automatically on power-up. A second set of connections are made to a 6-pin header which can be used for both programming and debugging the PIC if necessary. This additional programming circuitry isn`t necessary if you don`t have to program your PIC `on-board`. This last portion of the schematic is where the Audio signal will be generated. The 555 timer is setup so that it will output tones from 70 Hz upto ear-piercing 14000 Hz, when the 100k trimpot is varied.
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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