OT: My old brain is fading.

Dippy

Moderator
OT: Sorry. I'm doing a 'retro' thing...

Does anyone know of a supplier (UK and easy) for:

1. Latching relays with flag plus MECHANICAL reset. e.g. if it clicks 'off' you can press something and it clicks to the other position.
A bit like a circuit breaker I guess but really a relay (haha).

2. Showing age here, a little mechanical panel indicator which flip-flop a flag so you can see status when the power removed - I guess the guts would be like a latching relay(?).
I'm sure I've seen something (when I were a lad) in the form of a panel mounted lamp but the end had a bit of something inside that moved so you could see a little flag type thing.
.... or I may just be dreaming.


Appreciated.
 

premelec

Senior Member
Somewhere in my vast collection of electrical artifacts I have an annunciator panel which had six mechanical flags with labels on them... and a buzzer... I think these were located in the servant's quarters to indicated which button was pressed to ring the buzzer - the unit probably dates to before my time in the 1920s - and perhaps ran on #6 dry cells. Anyhow a dropped flag was reset by pushing it up by hand to re-latch... I've seen various flag indicator switches but no with all the functions you mention - have you tried fleabay? Wouldn't be too hard to modify some relays to do this function - or you could use low current magnetic circuit breakers - or ganged with a high current if you needed that... Happy tinkering - the weekend's up now!

To be a little more specific on the design I have: The label flag was hinged and held up by the 'relay armature' latch about 90 degrees rotated above its dropped position - dropped over the 'relay' magnet & armature.
 
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Pongo

Senior Member
For #2 are you thinking of the very old telephone switchboards where the jacks had a shutter that opened when the line was live so the operator could know where to insert the plug?
 

premelec

Senior Member
@Pongo - I've only seen the ones with lights next to the jack that indicated which were active... Didn't know of the kind you mention - must have been a mess of coils behind those panels!

@Skatt I've had a lot of fun with stepping relays - love that kerchunk! sound and have a few around but mostly they don't have a manual reset - though you could get a reading [up to the # of steps] of how many set signals came in....
 

BeanieBots

Moderator
FWIW I remember exactly what Dippy describes.
A panel pushbutton with a clear plastic button behind which was a bright flourescent green/yellow disk which was masked by a black cover when power was removed.
Also, surely many remember those electromechanical seven segment displays that all the petrol pumps used to have.
Sorry, no idea where you can get such things these days but I'd also be interested in a supply because they are the ultimate zero power indicator.
 

Dippy

Moderator
Exactly that BB and thanks all.
Looks like I might have to bodge - I mean 'engineer- something.
I haven't tried Fleabay - my knees start quivering at the mention :)
 

Buzby

Senior Member
...
2. Showing age here, a little mechanical panel indicator which flip-flop a flag so you can see status when the power removed - I guess the guts would be like a latching relay(?)....
These exist, they are used on defibrillators.

I know that, 'cos I saw one on mikeselectricstuff, when he did one of his teardowns.
 

Paix

Senior Member
Pongo is right, the old dolls eye type of manual telephone exchange had them and I remember having a unit with a white latched flag, 25mm x 25mm x 80mm, some years ago.
 

srnet

Senior Member
Sounds like something that would have been used in the Apollo missions.

I believe a lot of these were scrapped, many moons ago, but ought still to be in perfect condition and awaiting reclamation.
 

Pongo

Senior Member
Pongo is right, the old dolls eye type of manual telephone exchange had them and I remember having a unit with a white latched flag, 25mm x 25mm x 80mm, some years ago.
"Doll's eye" thank you, I just couldn't remember that term. Here's an example. These things were still in use in the UK into the early 70's.
 

Dippy

Moderator
srnet- "Apollo" & "many moons ago" .... very good :)


Thanks hippy, that looks like exactly the thing.

The last time I saw the style was some old gear from a lab.
They must have been latching/bistable as I was told that they were used so that the status of various internal things would be indicated when the device tripped or lost external power.

Are they called "dolls eye" or is that just slang?
I can't find anything around to buy.
 

Buzby

Senior Member
... A panel pushbutton with a clear plastic button behind which was a bright flourescent green/yellow disk which was masked by a black cover when power was removed...
and the picture from hippy.

These are not the same.

I have a Tektronix analyser with an on/off button which is like hippy's picture.
The coloured dot is displayed when the button is pressed 'on', and disappears when pressed 'off'.
It has nothing to do with whether or not power is flowing, it just shows the state of the switch.
 

hippy

Senior Member
The coloured dot is displayed when the button is pressed 'on', and disappears when pressed 'off'.
It has nothing to do with whether or not power is flowing, it just shows the state of the switch.
You're right; my picture indicates switch depression, not power flow.

I recall the eye lid cover used a mechanical linkage fitted to the switch by a mechanism like used on a click-down, click-up pen top. Push down, eye opens, switch locks in, push again and eye closes, switch pops-out. That recalls I had one in pieces so probably now have one less than I did have !
 

Buzby

Senior Member
Exactly right, that's how it works.

Mine, on the Tek, has lost it's clear cover, so I have to push the cylinder surrounding the dot.
Either that, or I just used the switched mains socket it's plugged into !
 

Dippy

Moderator
Aha, we might be at tangents here.
I was really after an indicator rather than a combined switch-indicator .. and bistable to boot.
 

Dippy

Moderator
Firsty, thank you hugely. This is greatly appreciated believe me.
The flipdot looks current and bang-on and ditto the flag relay.
Thanks Bill, Pongo and hippy and everyone else for pointing me to the indicators.
What a Forum!!
 

clockwork

Member
One place that MIGHT just have what you want is John Birkett's at 25 The Straight, Lincoln. Tel 01522 520767. John still has literally tons and tons of electronic bits and pieces of all vintages. You might just be lucky. However whilst John does have a Website you cannot contact him via it. Only way is to phone or call in person. He is only open three days a week as far as I know, Best day is probably Saturday. Then you just have to hope that Johns memory (he is in his eighties) reminds him where the rare but usefull items still lurk in his shops multiple store rooms.
The shop is a veritable Alladins cave for pilgrims seeking rare electronic treasures.

Clockwork
 

Paix

Senior Member
OMG, I bought a multimeter 20kohm/volt from Johnny Brikett in 1974. It's still the one that I use most today, although I only ever replaced the 22V battery once.
I was up the road at RAF Digby, Ashby de la Laund at the time. I never gave it a thought that the shop might still be there. JB will know what doll's eye indicators from a PMBX switchboard are. I do like the flip-disk indicators, but it's been a long time since I have seen them at Glasgow Central Station, or was it Euston? Impressive technology of it's time. Doubtless problematical as it aged and started not being quite as reliable.
 

saunj

Senior Member
I have 5 of these 'doll's eyes' from a US military aircraft. 8mm dia x 30 mm long, magnetic latching. They are usually reset by a second set of contacts, but you can reset by waving a magnet in front. You can have them for $1 each but I am in San Diego, California
 

Dippy

Moderator
Thanks for kind offer and info.
I've ordered the flipdots and (fingers crossed) should be in my hot sweaty hands soon.
They also do matrix and 7-seg, though I have no idea of price.
The single flipdot 'pixel' comes in various sizes and 1 or 2 coil and cost £8 to £15 each in small quantities.
 
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