That could work. I also have some left over from the 1970s to 1980s.
Joe
Passive frequency divider
Jul 29, 2026
Last reply: 3 weeks ago
22 Replies
I know SED is full of coffin dodgers but UJT's?
Depending on the nature of your source something like the following would work
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if you need an exact pulse count a 4029 could be used - pulse number into the jam inputs, and feed back (inverted) cout into cin. That would give a short duration pulse every count cycles.
In 1968 I designed a portable vidicon TV camera, BW system both the horizontal (50 Hz) and the vertical (15625 Hz) scan oscillators were UJTs. Easy to sync those too. It landed me a job at the national TV network. Interview: Do you know anything about TV? Reply: Well I have this camera here I designed, you can connect it to a TV if you like. There were a few more questions I remember... How many TV lines are there? 625 but there is interlace, 2 frames of 312.5 lines
These days the OPs problem is easily fixed by a single chip micro (no 4040 CMOS needed) Microchip 18F14K22 is what I use for all sort of things, from drones
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frequency counter:
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PIC projects here:
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But it requires one to be able to write PIC asm and understand its hardware, and it requires one to have or make a PIC programmer. OTOH it can do a whole lot more, has many internal features.
Advantage is: you only need one thing in stock and the hardware is simple. single chip solution. Price? About 3 US dollars
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So far, after many years, no FLASH problems yet. Have not used in space... But it has seen radiation.
Anyways without coding knowledge your option in the world are limited. Maybe these days one can ask AI to write the code? Or solve the problem?
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