When I show vintage electronics projects on this site, it’s usually just for the nostalgia value, since the modern replacement is usually much better and much cheaper than recreating the old version. Today’s project, however, turns out to be an exception. It’s such a niche product that there’s really not much available off the shelf. Forty years ago this month, August 1975, Popular Electronics carried the plans for this electronic scoreboard-timer for use in athletic events. The display could be toggled between showing the score or showing the time, and the clock could count either up or down. There was provision for adding a horn to sound when the clock got to zero.
The display board shown here measured 48 by 14 inches, and would be easily visible in a large gymnasium. But the entire device, including the display, was homemade, and it could easily be adapted to a larger size.
The individual digits each contained seven 7.5 watt christmas tree bulbs, along with two extra bulbs to serve as the colon when the time was being displayed. Each segment was turned off and on by a relay, making the basic design adaptable to an even larger scoreboard.
The guts of the unit consisted of 24 integrated circuits, most 74xx series TTL. The unit included a power supply (which used the AC power at timer for the clock) for the TTL voltages, and the lamps in the display unit ran directly off 120 volts.
The article billed the parts as costing about $100. Most of the parts (or modern equivalents) should be readily available from suppliers such as Jameco Electronics, probably for less money. While the price of a complete comparable scoreboard is probably lower today than it was forty years ago, a comparable one such as the one shown here is still considerably more expensive than the component parts for making one yourself.
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