hobbit@topaz.rutgers.edu (*Hobbit*) (04/22/89)
I just opened up what porports to be a battery charger for some unknown
kind of radio. It's a smallish box with a holder on top that has two little
spring-loaded pins down in the well, so you drop the radio in and it starts
charging. Inside are what you'd expect, a transformer, bridge, a cap, a
regulator, and then it gets seriously weird. Over at the other end of the
PCB are two 28-pin DIPs and a crystal. Now, since when does a lousy battery
charger need serious logic?! Naturally, my brandy-new NTE book *doesn't*
cross these chips. The charger's called "Smart Charger" [haw!!] and is made
by Alexander Mfg, Mason City Iowa.
The chips are:
MSM5842-19RS "OKI" in a diamond logo
ADC0808CCN National, I think
The negative side of the battery pins is fed off three ganged pins of the
ADC0808. Anyone know what these chips are? This whole picture is seriously
weird....
_H*larry@kitty.UUCP (Larry Lippman) (04/23/89)
In article <Apr.21.21.19.36.1989.3812@topaz.rutgers.edu>, hobbit@topaz.rutgers.edu (*Hobbit*) writes: > I just opened up what porports to be a battery charger for some unknown > kind of radio. It's a smallish box with a holder on top that has two little > spring-loaded pins down in the well, so you drop the radio in and it starts > charging. Inside are what you'd expect, a transformer, bridge, a cap, a > regulator, and then it gets seriously weird. Over at the other end of the > PCB are two 28-pin DIPs and a crystal. Now, since when does a lousy battery > charger need serious logic?! Naturally, my brandy-new NTE book *doesn't* > cross these chips. The charger's called "Smart Charger" [haw!!] and is made > by Alexander Mfg, Mason City Iowa. > > MSM5842-19RS "OKI" in a diamond logo > ADC0808CCN National, I think > > The negative side of the battery pins is fed off three ganged pins of the > ADC0808. Anyone know what these chips are? This whole picture is seriously > weird.... I'm impressed... This battery charger not only has a microprocessor, but also has an A/D converter to measure charging current and/or voltage. The OKI chip is a microprocessor with 768 bytes of ROM, 32 nibbles of RAM and about a dozen I/O pins. It runs at a maximum of 4 MHz. The National chip is an 8-bit A/D converter with internal 8-channel multiplexer. Sounds like someone has designed a battery charger circuit to do things the right way. <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP: {allegra|ames|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> VOICE: 716/688-1231, 716/773-1700 {att|hplabs|utzoo}!/ <> FAX: 716/741-9635, 716/773-2488 "Have you hugged your cat today?"