- on Education & Information
- Published in issue 3/2001 on page 0
Running Text Display with seven LEDs
In the search for original running text displays that catch your eye, manufacturers keep coming up with interesting variations that combine maximum functionality with minimum cost.Conventional running text displays use various sizes of arrays of light-emitting diodes or other optical display elements. For example, the Running Text Display described in the February 2000 Supplement of Elektor Electronics contains a total of 245 LEDs (7 × 35) in order to be able to display up to six characters at the same time. In order to keep current consumption, wiring effort and component costs within limits, the light-emitting diodes are operated in multiplexed mode in nearly all running text displays. This means that individual rows, consisting of seven diodes arranged in a vertical line, are driven at a rate of 1000 Hz (for example) and thus are lit for only around 1 ms.