In a reed relay, the tangs that come out of the capsule are welded od soldered to the copper pins that solder to the PCB. That make two thermocouple junctions. There is stress relief involved, because stress on the reeds can make the relay malfunction.
Really, get a reed relay, connect it to a good DVM, apply coil power, and watch.
We use latching versions of the Fujitsus for microvolt stuff. They cost a bit more.
DPDT is often handy.
But they do have unique properties which are sometimes useful. Nobody sane expects to use the same part for every job, and anybody sensible keeps track of stuff that can be bought off-the shelf to deal with specialised problems.
We don't "love" reeds, or China. We just object to dim-wits like you posting your fatuous misapprehensions about them and pretending you know what you are talking about.
I'm pretty confident that I haven't posted anything that ended up as being shown as coming from whit3rd at gmail.com. John Larkin doesn't seem to know how these things work.
Joe Gwinn snipped-for-privacy@comcast.net wrote in news: snipped-for-privacy@4ax.com:
I thought that the best contact surface/media was platinum.
John Larkin <jlarkin@highland_atwork_technology.com> wrote in news: snipped-for-privacy@4ax.com:
snip
High freq relays with SMA I/O ports are supposed to address small signal long term reliability.
A GP relay would if the right contact media is used and if it is environmentally sealed. Then each physical connection node needs to be gas tight as well Use an anti-oxidant paste like the cable TV guys use on outside F-fittings. Air exposed contacts can build a film if the atmosphere they are in.
The old reed switch operated pinball machines were a joy to work on because the contacts had to be 'burnished' individually because they used the cheap contact materials back then that would rub off if you cleaned them wrong. A poor reed switch was always the first thing one would search for when working on a faulty machine (that contained several dozen). And they switched higher currents and voltages then than today's modern pinballs, so the contacts could go bad pretty quickly. Especially since their closure usually involved the firing of a solenoid making for back EMF current and arcs at the contacts, etc.
Piglet snipped-for-privacy@hotmail.com wrote in news:saisfb$e1g$ snipped-for-privacy@dont-email.me:
Hahahaha... A quote...
ENG (gas-tight plastic sealed relays filled with insulting inert gases)
They have to be sealed to keep the insults inside.
Piglet snipped-for-privacy@hotmail.com wrote in news:saisfb$e1g$ snipped-for-privacy@dont-email.me:
Very nice. Page 11 up until they start going over their actual products is very informative about contact science.
Clifford Heath snipped-for-privacy@please.net wrote in news:168b11ac909b0362$1$2193376$ snipped-for-privacy@news.thecubenet.com:
Pretty goddamned good piece of gear anyway.
50% rate of intermittent or total failure in a $1600 appliance because of a badly installed $0.01 part does not constitute a "goddamned good piece of gear".
We live in 'opes. ;)
Cheers
Phil Hobbs
I thought that reed switch contacts were always sealed in a glass tube, so how were these pinball machine reed switches constructed? John
But they are absurdly expensive and don't mount on PC boards.
There are surface-mount RF relays. The Fujitsu FTR-B3GA relays are pretty good up to 3 GHz.
Clifford Heath snipped-for-privacy@please.net wrote in news:168deb1da11cc477$1$1356503$ snipped-for-privacy@news.thecubenet.com:
The one my boss had has lasted for years. The one he has in his new house is still running as well.
John Walliker snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:
Open air designs throughout the cabinet of the machine. They get actuated by the pinball hitting a bumper that has a lever or rod behind it that depresses the reeds together.
They're not 'reed switches' as we know them today, but that's what some people called them before 'reed switches' were as we know them today. They're a bit like ordinary relay contacts, but without the coil and operated by physical movement or impact.
We have had 10 years so far out of ours.
I'd call those leaf switches.
The problem I'm referring to is the models with a water flow sensor containing a reed switch to detect the rotor moving. The reed switches are soldered on to a rigid PCB with no provision for thermal expansion, so depending on the ambient temperature at the time it was soldered, a temperature excursion or/combined-with a slight shock cracks the glass at one end, and the reed becomes unreliable. It might be always on, always off, or might work normally. It might work at some ambient temperature and not at others. It will probably pass factory QA, under the same climate conditions where it was manufactured, but become unreliable as soon as the machine is put on a truck or a boat.
The effect of intermittently reporting water flow problems is very hard for service techs to diagnose. In our case the dishwasher is in a rental and we live in another city, so I wasn't there to chase it down myself - but it caused us dramas multiple times with tenants complaining about flakey behaviour. There are many reports online of the same kind of failure, and no clear "here's what's wrong, here's how to fix it" - so I know this is not just a one-off issue with our unit.
All for not soldering the damn thing down with a tiny allowance for thermal expansion. Now that I've fixed it, I'm sure the washer will be good for ten years. But this was just to point out that 99% good reliable engineering is still 1% unreliable, and that can spoil the whole party.
Clifford Heath
I worked on pinballs until ca 1977 and I never saw a reed switch in one. Jukeboxes had a maybe a few.
gray_wolf <gray_wolf@howling_mad.com> wrote in news:iQzEI.104771$ snipped-for-privacy@fx43.iad:
What do you call them then? The early pinballs had several open contacts in them. Hell the left and right flipper actuator switches were (and still are) open contact devices.
Yikes. The rep says prices on the surface-mount parts is
"$73.96 - $8.28, depending on the quantity and the part number."
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