analytical video display - turns a TV set into a colourful bar-graph display with a full scale sensitivity of 1 V d.c.

analytical video display The third, and last, part of the real-time analyser is dealt with elsewhere in this issue. That project is now complete but it can be enhanced with the addition of this display which shows the output of the analyser in colour on a normal TV set or monitor. The bar for each output channel is sub-divided into 32 sections each of which represents a step of 1 dB. The colour of the bar changes per dB so that the value of each bar is easily read. This circuit is also extremely suitable for any application where it is useful to see a read-out in bars on a screen. The real-time analyser, which is now com- plete, provides its read-out on a LED display built up from 330 discrete LEDs. This is more than sufficient for "personal" use. It can sometimes be useful to have a larger display for some applications, such as for demonstration purposes or to be able to see the result at a greater distance from the analyser. This circuit forms the output of the 30 rectifiers int...