Troubleshooting an infrared beam race timer

Swell batteries - While working for BT I was on the team that wrote the software for the engineers to use the https://www.handheldsystems.com/handhelds/ms-dos/fs2/fs2.htm I did a bit of "heath robinson" setup to and wrote a C routine to TRY and detect if the engineer was trying to recharge ordinary batteries because if they did they would SWELL and you could not get the AA cells out of the hammer head. This was back in 1994ish

John Harrison

Lost a few of my toys to leaky batteries - particularly Duracell. Particularly annoying are the ones I got in the US that don't exist over here. I recently found a really old Duracell battery still in its pack that was fine, alongside some newer ones that weren't. Race to the bottom, obviously.

Mark Gray

I'm replacing 16F88 in a bunch of products. They are still available, but not in volume. DIP is better. My advice is buy 12-24 months' supply. Microchip have always been good at providing pin-compatible upgrade routes. I'm not modifying my 16F88 boards, just porting to a new part.

Mike Page

Looking for clues... https://youtu.be/92wCPfqyVbg

Michael Thompson

3D printing a battery holder should be easy enough. As for the contacts - Not sure if PLA is more brittle or not but ABS is definitely good for flexible / springy parts (the leg springs for the ZX Spectrum+ are made of ABS). You could use copper tape on something like that or even a flat piece mounted on a standard spring.

Raven Luni

I hope my faves aren't going extinct. I tend to stick with microcontrollers I'm comfortable with, and they are getting pretty old. Notably PIC12F629 and PIC16F627A

Big Clive

Looks ripe for 18650 mod with balanced charging board. Plenty of room and the design provides lots of inspiration for other builds. Incidentally, I spent a few years as a fraud investigator and had someone working at Bulgin Components in Barking, London under their maiden name. Flatly denied working for Bulgin (pronounced buul(Jinn) by the lead investigator. When we thanked the woman for coming in (sometimes tip-offs are wrong) we explained we would get a description of the worker from the management of the company. The woman went outside, had a heated conversation with her husband and then came back in and said “did you mean Bul(g-inn)?”. Owed 16k in benefits. Was on a great wage there full time for years. All their pay records were all written on paper, tied up in brown paper and twine each month. Had to go back approximately 5 Years. Really unique (though this was in the early 90’s).

Simon York

I seem to remember the older Atmels (AT90S2313, etc.) having code protection. I can't for the life of me imagine what those extra chips are for unless they just handle the IR transmit / receive functionality. I wouldn't think you'd need separate chips for that, though. And why grind off the numbers at all - just so people can't make compatible hardware? Seems to me that anyone who could do that could pretty easily figure out what the chips were, or just reverse-engineer the IR stream directly.

Circuitmike

LOL. Me watching video: "You do not mix batteries!" Clive 1 second later: "You do not mix batteries!"

Tell me about it. I have a client using 2 x 2 D cell holders per product. You would not believe the asking price. But they're reliable and have an IP rating. They're pondering moving to Lithium.

Mike Page

Nice! Quite old school. 2021 is not a good year for old micros :/ So many obsolete / unbuyable parts. Like an extinction event. I have many questions about this. Like how millisecond timing is maintained over what might be an iffy RF link? Like what are those scratched off parts, CPLD? And why they need them - do the old Atmels lack code protection? I never used them seriously back in the 90s. Would have liked to see that TO220 tab riveted down, and some goop on the antenna tube.

Mike Page

The battery holders are only £10.80 each at RS ( https://uk.rs-online.com/web/p/battery-holders/4573805 )

I did use vinegar to neutralise the electrolyte, then rinsed the contacts, dried them and cleaned the contact surface.

Big Clive

It does look a well made product.

Dr Andy Hill

Just clean up the metal parts with vinegar and then baking soda, solder over the batterie contact points, freshen up the wire connections and you are good to go. As long as the spring has sufficient tension, It'll be fine.

https://www.ebay.co.uk/itm/174283236756?hash=item2894172594:g:9N8AAOSw3DFevZC8

Looks like CPC have something very similar.

Tokkan FX

I knew about removing batteries when a device is not going to be used for a while, but I didn't realize that mixing batteries with different amounts of charge could cause them to leak.

Michael Dunn

"Dog speed to you sir" .... sounds legit...

Tim Albers

It's not a bad price for such a specialist item. I wonder if they make other stuff too.

Big Clive

I found them in stock at RS components.

Big Clive

Just had a nosy and TME.EU seem to be the only place with them available at the minute..... https://www.tme.eu/en/details/bxs012_1/batteries-holders/bulgin/

John Carr

For almost 700 UK bux, I don't think you can find something else so specialized and so well built.

Witold Witkowski