A `video-digitiser` (also known as a `frame grabber`) captures pictures from a TV set, camera, or video recorder, etc. , and forwards them to a computer for display, storage, or general manipulation. This document describes a home-built digitiser which interfaces to an EPP (or bi-directional) parallel port on IBM PCs. This frame grabber
Click here to download the full size of the above Circuit.
design digitises pictures to very high quality in monochrome (8-bit black & white). Although designed for the European standard 625-line / 50Hz TV system, it should work with the American 525-line / 60Hz standard with minimal modification. Before embarking on the project, please be sure to realise that this design will not capture movies. At best, it can manage a couple of frames per second. Note also that as described, the circuit collects its picture from a succession of frames. Consequently the image must remain fairly still for the half-second or so taken to capture it. A competent constructor could purchase a larger and more expensive memory chip and modify (simplify) the circuit to overcome the latter limitation if desired (see the Mk. II Video Digitiser ). Television equipment uses a simple composite video signal which carries all the picture information. Pictures are conveyed as a continuous sequence of frames, each taking 1/25 second. Within each frame are 625 horizontal scan lines, transmitted in turn starting at the top. [To reduce flicker, each frame is actually transmitted as two consecutive fields, the first containing odd-numbered lines, and the second filling in the even numbered, a technique known as interlacing. This cunning trick ups the refresh rate to 50Hz, without increasing the signal bandwidth. ] All video recorders and many TV sets will have a composite video output, usually using a BNC or phono...
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: