2018-05-27

Eurit 133 ISDN/DECT base station


 No screws, easy to open with flat screwdriver
 Gold-plated PCB, no screws and very nice build quality.


SC14425 from National Semiconductors - Complete Baseband processor for DECT Base Stations with Caller-id and Handsfree
 TDA7052B - 1W audio amplifier with DC volume control
 Infineon PSB2186N - ISDN 2B+D interface
 Two radio antennas

2018-05-26

DECT base station

 Base station for cordless (DECT) phone.



 RU1890B DECT radio module.

 SST37VF010 - 1Mbit NOR FLASH. There is also 24C64 EEPROM.
 Two radio antennas
Under small copper shield/radiator - IC-397004B, seems to be specialized controller.

"Analytical" weight scale

 This is one of many similar "analytical" weight scales or "fat scales" - described as capable of measuring body fat, water, muscle and bone weight/percentage. I bought the cheapest one (~$10, so basically same price as "regular" weight scale) but there are many similar ones, sometimes slightly more expensive. I think they can be recognized with metal stripes on the front and three buttons: up/down/set. They are sold under many brands, with some cosmetic differences, powered by 2 AAA cells or single CR2032.

 Buttons are actually mechanical and located on the side.
I was thinking that this weight scale uses some kind of frequency/impedance analysis, but it seems to me now that it actually measures only weight. Body components percentage is just guess, based on entered height/gender/age (there are 12 memory cells for personal data). I haven't disassembled it (I'm not sure if it would be possible without damaging), but it seems that metal strips on the top are not even connected to anything. Also, percentage measurements does not change regardless of if I'm stepping on it with bare foot or in (isolating) shoes.
In conclusion - if you are looking for real analytical weight scale, don't buy this one.

2018-05-13

Harman Kardon HK206 PC speakers

Volume control is integrated with ON/OFF switch. I'm not sure if this switch is working as intended here as is it works really weird.

According to label speakers are manufactured by Samsung, although there is Dell mark on the PCB



Samsung 08G11ARH 4Ohm 3W speakers

TDA1517P power amplifier + LM324


"DELL 2.0" mark on the PCB + 2002.01.22
Speakers are receiving good reviews and I can confirm that they sound good despite not so impressive amplifier.

2018-03-24

EX668 - little power supply that blows

I was missing some power supply plug and as it's difficult to buy the right one I've bought cheap universal power supply (EX668 or YC668 as marked on the box) that comes with the set of seven plugs.

 I've noticed small detrition at the edge... Was it some kind of refurb? Other than that I've noticed that voltage selector switch is not too precise (but nothing to worry about).
 Few minutes later sparks were flying when power supply was connected for the first time (without load). B16 fuse for this phase in my flat was switched off. Nice...
Power supply seemed clued at first (no screws) but it was actually really easy (perhaps too easy if you have small children) to open with just four latches on the sides. Inside 1A fuse was blown (with small glass pieces scattered) and HV switching transistor was cracked.

 On a plus side: components are nicely labelered with values on the top side of the PCB.



 Transistor: MJE13007.
 The worse part might be that power plugs don't actually fit the cord. The seem like they might, but connectors in socket are spaced little more widely than in plug and it's very likely that the plug would break when using force.