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+--- Thread: 1826-0287 chip (/thread-7245.html)
1826-0287 chip - teenix - 11-17-2016 12:07 AM
Hi all,
This chip seems to appear in the printer type calculators like HP-19C and HP-10
It seems to be a mystery. Anyone ever find out what it is for?
cheers
Tony
RE: 1826-0287 chip - Dave Frederickson - 11-17-2016 12:26 AM
According to the HP-97 service manual, it's a quad comparator used in the motor speed control circuit. See para. 2-28 for a complete description. The 19C schematic by Tony Duell identifies it as an LM339.
RE: 1826-0287 chip - teenix - 11-17-2016 04:59 AM
(11-17-2016 12:26 AM)Dave Frederickson Wrote: According to the HP-97 service manual, it's a quad comparator used in the motor speed control circuit. See para. 2-28 for a complete description. The 19C schematic by Tony Duell identifies it as an LM339.
Cool, thanks Dave.