I needed a time display on my bedside table and I wanted it with an electronic vintage touch. So I gathered:
- 4x HP 5082-7300 displays
- an Arduino-like board
- an RTC module
- a perfboard
- some female pin headers
- wire, solder, tools, ...
- a 5 Vdc source
Optionally:
- an LDR
- a couple of N.O. pushbuttons
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| Four HP 5082-7300 displays. |
An HP 5082-7300 display is an early LED display developed before 7-segments became the de-facto standard. It includes a BCD decoder and it displays 0-9, dash and blank and a right hand side decimal point. Each segment is composed of few LED dots, so it mimicks a dot-matrix display. It works from about 4 V to 5.5 V and it drains an average of 100 mA at 5 V: that's half a Watt per display! We are talking about late 1970's technology.
So, why using these power hungry displays in 2016? Simple: to learn something new and to save old technology from the recycle bin. Moreover a modern microcontroller makes it very easy to produce a BCD sequence that represents the time of the day.
