MRR Electronics Anachronism - Circuitron FL-2HD

[C855B]

Working on a "quick-and-dirty" for the club, I picked up a Circuitron flasher for the project from a fave online retailer. On opening the package, I experienced a bit of time-warp whiplash:



The design, board material, board markings, assembly method, component selections - all from the 1970s. I guess there's value in leveraging a working design for as long as you can get value out of it, but...  damn, talk about something desperately needing an update.

I would have much rather used the ngineering.com flasher board, but the current requirements for the club project were potentially high. Even adding Ngineering's booster board still wouldn't handle it. I guess there's something to be said for good, old-fashioned brute force tech from 40 years ago.

[MK]

What are you complaining about????  There's an integrated circuit there!   

Look at the spacing of the components!  I think I did a project in high school with a home etched board that had denser component layout than that! 

[C855B]

What are you complaining about????  There's an integrated circuit there!   

Barely! I was playing with MC140xx-series CMOS when interning at NASA in '72! That's some old $#!+!!!

[babbo_enzo]

Well, but we land on the moon using a Z80 and 64K of memory, right?


YES... time-warp ... but I (still?) remember these logic game!
Wonder if this cards are still on sales?

[Point353]

The 9336 datecode on the IC would indicate that it was made during the 36th week of 1993.
Makes you wonder about the age of those electrolytic capacitors.

[peteski]

I like the simplicity of that circuit. It will outlast any of the flash-memory-based microcontroller solutions offered nowadays. Not that we (old modelers) need the worry about the longevity.   Speaking of simple circuits, I still have an old-school CMOS  logic lamp sequencer I promised to design for @pedro    Don't worry Pedro, I haven't forgotten.

The caps are likely fine (they have been in storage, not in use).  If you are hell-bent on using modern flasher, you can always build an output current buffer to supply much higher current.

[djconway]

At least it's not a 555 timer and a jk flip flop.  Built my first grade crossing circuit with those back in 1973.
I'll have to see if I still have it in one of the boxes of RR stuff in the basement.

[Point353]

The caps are likely fine (they have been in storage, not in use).

If the IC is about 25 years old, might the caps be that old, as well?
In your opinion, what's an acceptable limit on storage life for an aluminum electrolytic type capacitor?

[C855B]

For all its antiqueness, it works fine, gets the desired result:

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Now you see why I needed more than the "usual" current capacity.

[peteski]

If the IC is about 25 years old, might the caps be that old, as well?
In your opinion, what's an acceptable limit on storage life for an aluminum electrolytic type capacitor?

In my opinion?  As long as they retain their rated capacitance within the tolerance. 
Could be decades.  I have some in my parts bins which are at least 30-40 years old. I could go through them with my capacitance meter to see how well they are, then expose them to the rated voltage and see how they behave. If you do some research online (like https://electronics.stackexchange.com/questions/8794/do-electrolytic-capacitors-have-a-limited-shelf-life )it is only couple of years. But from anecdotal evidence in non-critical consumer applications, aluminum electrolytic caps remain useful for a very long time.  I have several pieces of consumer electronics (VCR, TV, Audio equipment and other devices) which still function just fine.