Common Emitter

2021-09-11

Citizen SR-260 calculator

Popular scientific calculator - I've seen it in use around 2003. Apparently replaced by model SR-260N.

Case is slightly flimsy - perhaps because I don't have other part, cover.

Two alcaline GPA76 cells.

Two screws on the back and few latches around - rather easy to open.

2021-09-04

2 charging channels (2 x 2 AA/AAA), relatively low charging current, no detection of fully charged accumulators, just 11 h timer. Might be useful for complementing modern chargers that sometimes seem too smart refusing to charge.

Open circuit voltage on each channel: 11.6V.

Transformer: outputtting 7.7V RMS and 5V RMS.

Visible corrosion damage - these pictures were taken after cleaning. Fortunately PCB traces does not seem to be broken. Two electrolytic capacitors were replaced as they seemed to be corroded, though their capacitance was fine.

Strangely only one problem was found: not working LED in first channel.

Timer: HCF4541.

2021-07-24

Olympus X-44 compact camera

Compact camera bought in 2011, with 14MP sensor, 5x optical zoom, powered by two AA cells.

Failed in 2021 (though occasionally failing same way year later, so it was not instantaneous), making all photos very overexposed, almost all white. This is pretty much sure sign of shutter failure - either mechanically stuck or not working due to broken flex cable. I've disassembled it hoping for the first case.

Outer shell is pretty easy to open, with no latches, but different screw sizes might need attention when reassembling.

Main chip: NOVATEK NT96450BG

"First layer" of lens module: focus lens driven by small motor.

Shutter module with two electromagnets. Held by latches.

Opening lens from the front was a mistake - it was not needed.

Reason of failure: broken flex tape. While replacement tape is available at reasonable price (~$5), I've given up at the moment. My lack of experience with cameras made reassembling it more difficult than it should be.

2021-06-12

C++ Builder 10.3.3 rendering issue

I've installed C++ Builder 10.3.3 few days ago on my secondary PC. Not the newest machine, running Windows 7 64-bit, but still quite capable with quad core CPU and GT430 graphics card. C++ Builder was pretty much useless on it though:

Once new project was created or old project was opened most of the GUI was either frozen or refreshing with huge delay. At the same time bds.exe was using 100% time of one of the cores. What is weird is that once C++ Builder window width was reduced to about 1100 pixels the problem was gone. Still, working with window width reduced to half of screen width would be very painful.

Solution is easy to find: disable support for themes in IDE (HKEY_CURRENT_USER\Software\Embarcadero\BDS\20.0\Theme\Enabled, set to 0):