|
General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
|
Thread Tools |
3rd Sep 2022, 9:33 am | #61 | |
Octode
Join Date: Jun 2011
Location: West Midlands, UK.
Posts: 1,571
|
Re: How would we design electronics to last 100 years?
Quote:
However, I predict that the horse will make a comeback! |
|
3rd Sep 2022, 10:38 am | #62 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
|
Re: How would we design electronics to last 100 years?
At the end of the day if the plug fails to fit on the new bit of gizmo, the flat panel TV that was marvelled two years ago ends up at the tip.
It is interesting to note that in the 'Murphy News' 1952 they suggested that a 12" TV in the home situation is all that was required and it would no doubt become a standard. Within a few months they introduced the 15" V204 and were so swamped with orders that it created chaos at the factory because Ediswan/Mazda could not supply the 15" CRM152A tubes! [To say nothing of the large numbers that failed under guarantee] I suppose you could say, where will it end but, they must have said that in 1946. John. |
3rd Sep 2022, 11:57 am | #63 |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
|
Re: How would we design electronics to last 100 years?
It'll end when we all have a plug on the back of our skull for direct neural interface
__________________
Doomed for a certain term to walk the night |
3rd Sep 2022, 12:18 pm | #64 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
|
Re: How would we design electronics to last 100 years?
- The way things are going, we could be eating horse before long- in which case their obsolescence would be reversed. A revived use for an existing technology.
Could the submarine repeater Craig mentions have been left on the seabed when it reached end of life on an economic basis? (We'll never get funding for this, the interest lies with U-boats, gold bars and sunken ships where loss of life occurred.) Dave |
3rd Sep 2022, 2:35 pm | #65 |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
Posts: 2,529
|
Re: How would we design electronics to last 100 years?
|
3rd Sep 2022, 2:49 pm | #66 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,799
|
Re: How would we design electronics to last 100 years?
Could we convince the 'phools that the very very special valves lying on the ocean bed in disused repeaters of disused lines would give their system amazing 'authority' and are therefore well worth the price of recovering and salvaging them?
Many of them were made by <cue angel chorus> Western Electric. Nuff said? David (upping the security on the horses)
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
3rd Sep 2022, 4:59 pm | #67 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
|
Re: How would we design electronics to last 100 years?
I'm thinking there are 2 separate issues to consider here:
1] Designing a 'thing' so it will continue to function for 100 years and 2] Designing a thing so it will still be practically usable in the world 100 years from now. [2] is a real problem; technologies evolve and make things obsolete, the lifespan of ideas/technologies is getting shorter as we evolve. Standards change, accepted practice changes. A 1922 radio would probably be a crystal-set - while it may still work it's not going to be a truly-satisfactory entertainment-device for the vast majority of peoiple; likewise a 1922 telephone would not meet the expectations of the 2022 user. 1922 'computer' - back then it would have probably been a hand-cranked mechanical tally-record calculator operated by a 'computor' [typically a young unmarried woman, one of my grandparents was so employed by the Inland Revenue. She had to leave her Civil Service job when she got married]. Consideration [1] is more interesting. There are two enemies of long-life; heat and humidity. So if you want something to continue working for a long time, you need to manage both. Heat: get rid of it [or don't create it in the first place]. Massively over-rated components [think 5-Watt resistors dissipating 250 Milliwatts] and big heatsinks. We've all seen PCBs charred to the point of self-combustion because a heat-dissipating component has tried to use the PCB as a heatsink. 1960s valve TVs regularly cooked their PCBs around the bases of high-power valves, the problem continues with hard-worked diodes in modern SMPS. Fan-cooling is no good - can you show me a fan whose bearings will run for 100 years without seizing? Even if well-heatsunk, internal-to-a-device heat is still a problem: plenty of 1970s ham-radio transceivers have been rendered scrap because the repeated thermal-cycling of their 'block' PA stage has caused fatigue-fractures of the little wires between the semiconductor 'die' and the leadout pins. Hello, Mitsubishi: I'm looking at you. The humidity/environmental issue: moisture causes corrosion, and oxygen accelerates it. So think of putting your '100 year' design in an hermetically sealed enclosure, perfusing it with a dry inert gas, and including desiccators to trap any moisture that does get in. Even after all that, you still potentiually have issues. Mechanical contacts [switches. relays, the rotor-to-ground connection of variable capacitors, plugs/sockets/valve-bases] all go intermittent - so design them out: use PIN-diodes for switching, varicap diodes instead of mechanical capacitors, and avoid valve-bases by using the wire-leaded miniature valves produced for missile/avionics applications in the 50s/60s. There are vacuum-sealed relays and variable-capacitors for high-power RF applications, but at eye-wateringly-high prices! And avoid interconnections! PCBs will always have the 'dry-joint' problem: I remember some 'sixties military gear used ceramic 'PCBs' with the individual component leadouts welded to the tracks using a process a bit like the spot-welding used to make car bodies. No solder involved! [so no dry-joints]. Paradoxically, "Designing for maintainability" - meaning easily-interchangeable modules/parts - can be the enemy of long-term reliability when the ability-to-interchange-parts introduces future contact-problems. When your flight-computer's nearest field-service engineer is based a couple of light-years away, you need to consider these issues!
__________________
I'm the Operator of my Pocket Calculator. -Kraftwerk. |
3rd Sep 2022, 5:24 pm | #68 | |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
|
Re: How would we design electronics to last 100 years?
Quote:
No supermarket check out, paying for fuel and all your medical records. Sounds crazy but if you had told me in 1960 we would have a handheld colour TV, working off 4 penlight batteries in just over a decade, I would have thought you were crazy! We certainly need products that last 10 years without giving problems and this I feel would be very easy to achieve. Cost is everything. John. |
|
3rd Sep 2022, 6:51 pm | #69 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,316
|
Re: How would we design electronics to last 100 years?
Looking through the CPC online catalogue for replacement electrolytics for my set-top boxes, I noticed that the specified lives at their respective maximum temperatures ( 85° or 105°) varied from 500 hours to 4000 hours. The ones I was replacing were all 105° rated and I ordered 105° equivalents with the longest specified lives. 1000 hours is just under 6 weeks, and I had been leaving the Icecrypt box switched on all the time, only turning off the TV, but will now be turning both off when not in use.
Last edited by emeritus; 3rd Sep 2022 at 6:55 pm. Reason: typos |
3rd Sep 2022, 7:35 pm | #70 | |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
|
Re: How would we design electronics to last 100 years?
Quote:
The upshot of Arrhenius with electrolytic capacitor life is that the lifetime doubles for every 10C reduction in temperature. So going from 105C to 25C increases the lifetime by 256. So for the capacitors you mention with a 1000 hour lifetime (at 105C) will last 256,000 hours at 25C, or about 30 years. Of course other mechanisms might kick in before those 30 years is up, such as degraded seals, seal permeability etc. And for me at least it is somewhat academic, because in 30 years I will in all likelihood be pushing up daisies! Craig
__________________
Doomed for a certain term to walk the night |
|
3rd Sep 2022, 7:38 pm | #71 |
Nonode
Join Date: Jun 2016
Location: Bognor Regis, West Sussex, UK.
Posts: 2,287
|
Re: How would we design electronics to last 100 years?
Thanks G6Tanuki, very interesting.
With reference to space use I think it was Robert Heinlein who suggested that in space, or on the moon, valves could be constructed "open", without envelopes, just the electrodes, using the vacuum of space. Just micro meteorites to cope with. Peter |
3rd Sep 2022, 7:52 pm | #72 |
Octode
Join Date: Jul 2011
Location: Leicester, Leics. UK.
Posts: 1,681
|
Re: How would we design electronics to last 100 years?
Voyagers 1 and 2 must be a good example of longevity and resilience and the benefits thereof. Not particularly old at 1977, but they have been through a lot and manage to keep going!
|
3rd Sep 2022, 10:42 pm | #73 |
Dekatron
Join Date: Aug 2003
Location: near Reading (and sometimes Torquay)
Posts: 3,086
|
Re: How would we design electronics to last 100 years?
Yes, they keep going but are not 100% working as is often the way with long distance space craft. The cleverness is to avoid single point total failures and be able to work round faults. So does that qualify or not?
I have an electronic device that is over 100 years old and works - after replacing the (missing, presumed dead) valve. Incredibly I found that the batteries that it uses are still made! |
3rd Sep 2022, 11:16 pm | #74 |
Octode
Join Date: Jul 2011
Location: Staffordshire Moorlands, UK.
Posts: 1,464
|
Re: How would we design electronics to last 100 years?
Crikey, I remember being enthralled by the letters page exchanges he generated in Wireless World, I revisited them a few years back (after graduating, growing up and gaining a career's worth of experience ) and it was than that realised just how naive I was in the mid 70's and also what utter twaddle he was peddling.
Steve.
__________________
Those who lack imagination cannot imagine what is lacking... |
4th Sep 2022, 1:09 am | #75 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,799
|
Re: How would we design electronics to last 100 years?
He was involved with Clive Sinclair and various ideas about wafer scale integration and self-healing logic networks. I suppose their quality is best assessed by how the ideas sank and stayed sunken. But Catt is probably involved in any patents in that area associated with Sinclair/Anamartic etc.
Twaddle is putting it mildly. David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
4th Sep 2022, 2:35 am | #76 |
Octode
Join Date: Jul 2011
Location: Staffordshire Moorlands, UK.
Posts: 1,464
|
Re: How would we design electronics to last 100 years?
I thought it best to be understated
One positive is that those WW exchanges challenged what I was being taught at the time and caused me to go through a process of examining the received wisdom. The whole thing increased my understanding. Steve.
__________________
Those who lack imagination cannot imagine what is lacking... Last edited by fetteler; 4th Sep 2022 at 2:44 am. |
4th Sep 2022, 10:25 am | #77 | |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
|
Re: How would we design electronics to last 100 years?
Quote:
The power source is a radioisotope thermoelectric generator. And the final lifetime of Voyager 1 and 2 is the half life of the radioisotope. These are used for spacecraft heading away from the sun, where solar panels would be useless. It is one of the reasons that Cassini was crashed into Saturn rather than ending up on a moon with potential life. They said that it was to do with bacterial contamination, but actually it was a whole bunch of highly radioactive materials in the thermoelectric generator. Lots of stuff out there about these including a Wikipedia article https://en.wikipedia.org/wiki/Radioi...tric_generator Craig
__________________
Doomed for a certain term to walk the night |
|
4th Sep 2022, 10:35 am | #78 |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
|
Re: How would we design electronics to last 100 years?
The other thing with the Voyagers at 22 light hours distant is the glacial data rate. The typical power transmitted from a space vehicle is a few tens of Watts. New Horizons, that visited Pluto and is now wandering around looking at other dwarf planets, has a 12W transmitter.
Voyagers' transmitters are 22.5W. Bepi-Columbo has 8 W on the Ka band and 30 W on the X band transmitters, because it is transmitting pretty close to a very large noise source (the Sun). There is also plenty of light for the solar panels, so they can afford extra transmitter power. These always operate in the microwave region, and are generated by travelling wave tubes. Craig
__________________
Doomed for a certain term to walk the night Last edited by Craig Sawyers; 4th Sep 2022 at 10:41 am. |
4th Sep 2022, 10:42 am | #79 | |
Heptode
Join Date: Feb 2021
Location: Edinburgh, Scotland, UK.
Posts: 528
|
Re: How would we design electronics to last 100 years?
Quote:
https://www.xppower.com/resources/bl...power-supplies |
|
4th Sep 2022, 11:07 am | #80 | |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
|
Re: How would we design electronics to last 100 years?
Quote:
Craig
__________________
Doomed for a certain term to walk the night |
|