An ebay find made its way into the lab- an industrial quality DMM from Hioki, made in 1984! The meter has some pretty good specs as shown in this datasheet:
- 3.5 digit (1999 count), 0.5% on DC voltage
- 20uA DC current range with 10nA resolution
- 1G input resistance on 200mV range
- Drop proof to 1 meter
- Dust sealed.
- 500 hours battery life using 2 AA
- Neon indicator of overvoltage Continue reading
Today’s teardown target is an early 1990’s electronic organizer from Casio. Casio Digital Diary SF-4000, complete with a travel guide!
Interesting mix of keys- membranes plus some hard buttons
Today we have a teardown of a Soviet calculator Elektronika MK 51( Электроника МК 51) for those familiar with the language. It was bought new in 1993, worked (sorta) for a few years and just drove me absolutely nuts with its lack of any reliability. The design is supposedly a clone of Casio FX-2500