This week’s part of the week is a Linear Technology’s LT8584. The part is a DC-DC converter that is designed for a very specific purpose- active balancing of battery cells. In a typical long battery string, no matter how tightly matched initially, there will always be cells that end up with a bit more or a bit less charge. Over time these imbalances start affecting what the battery can deliver, as one week cell may trigger undervoltage limit for example and shut the whole pack down despite other cells being perfectly happy. Continue reading
Author Archives: reagle
Philips Sonicare HX6710 teardown and repair
Today we have a new subject to tear down- my own Sonicare toothbrush. At the end of a brushing cycle it made a short “Beep” noise and went silent. No reaction to button press or to putting it on a charger. No lights, sounds or anything. Oh well, might as well take it apart.
“This digital electronic device is not a toy”
A silly looking box showed up in the mail a few days ago. It was attached to a spam mailer from a local car stealership proclaiming that I have already won a car, and just need to confirm the number this thing spits matches theirs. Naturally I took it apart:
Keithley 172A DMM in pictures
Another ebay find- a vintage Keithley 172 multimeter. The datecodes on the parts range from 1978 to 1984, placing the final assembly somewhere in mid-1980s. It seems fully functional, but could use a bit of a calibration to regain its past precision.
LM3916 LED bargraph/ VU meter
Available on Tindie is a new kit by Kuzyatech- an LM3916 based VU meter/bargraph driver.
Adjustable LM317 power supply kit (Version B1)
The new version of LM317 voltage regulator kit (Rev B1) is finally here. This version implements a few useful enhancement over the A1 release making it a much more versatile board. The kit is available on Tindie– the marketplace for makers. Continue reading
Testing laptop battery: pinout, SMBus, charge capacity
Introduction:
As a result of visiting Hamfest, I ended up with a laptop to take apart – a fairly new Toshiba Satellite C675D with a broken screen. It’s not a Hamfest if you don’t bring home something to take apart of course! Today we’ll be testing the battery it came with to see if it’s salvageable.The date code says it was made in 11/2011
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2013 Rochester Hamfest at RIT
It’s been year and the RIT Hamfest is once again upon us. A few pictures of interesting things we stumbled on. I can’t claim to know what some of them are though!
Eagle Aspen DISTAMP-25-GX teardown in pictures
This unit was used for a few years with a very limited success until I finally got fed up and decided to peek inside. The always warm case and constant 7W power draw did not help its cause either. As one of the 2 star reviews on Amazon concluded- don’t bother buying one of these.
Vintage DMM- Hioki 3200-50
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