| General > General Technical Chat |
| Looking inside a flown Soyuz space clock |
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| wraper:
It's all TTL. 133 series is a clone of SN54xx. 134 series SN54L. 514ИД2 led driver has no western counterpart. |
| richnormand:
Hope they post a follow up video if they manage to power it. |
| janoc:
Also I am pretty sure Smithonian has a clock like this already - they have several flown Soyuz capsules, AFAIK. Flown Soyuz TM hardware is not exactly that rare, given how many of those capsules have been made and used. |
| floobydust:
--- Quote from: wraper on December 09, 2019, 11:04:00 am ---It's all TTL. 133 series is a clone of SN54xx. 134 series SN54L. 514ИД2 led driver has no western counterpart. --- End quote --- The IC count seems high, I see a sandwich of 8 boards and about 135 of 14-pin IC's total in the logic sections. For a six digit clock with count down timer? That's why I thought small-scale integration, few gates per IC. No 7490 similar part but maybe 7447 like for the LED driver. Have to see it running, if it's a state-machine and why so many I/O pins on the main connector. I think it's more than a clock. |
| duak:
Neat stuff! I like the little switch guards. I designed a piece of equipment that flew in aircraft (not space) and I used U shaped handles to prevent some lever switches from being thrown accidently. Not as spiffy as some special hardware but it worked; it just didn't have the aerospace 'look'. I don't know what all the functions of this chrono-gizmo are so I'm just throwing out some chip counts If I had to do this in 1975: Timebase block: 7 = 1 Hz from 1 MHz needs 6 decade counters & a mux to select input source for clock & timer, Current time block: 8 = 6 decade counters + 2 logic to preset counters to correct time and handle 24 hours Countdown timer block: 6 = 4 decade counters + 2 logic to preset counters Display block: 10 decoder drivers I/O receivers and transmitters, maybe RS-422? Switch debouncing Power supply This would put the chip count in the mid 30's. If there were special functions like external preloading of values, generation of time code blocks for other equipment, multiple times or mission day count, it could increase the count considerably because of adding muxes or busses. Also, space stuff generally needs rad-hardened chips which may limit the selection. A state machine with a RAM might be interesting, but it may not be available. Even some MSI like a decade counter could be a problem. |
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