Elastomer Strips - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

AC/HL · 25th Aug 2018, 3:42 pm

Do you mean how many ways to use elastomer strips, or electrical connections in general?

John10b · 25th Aug 2018, 4:46 pm

I was just wondering how many ways generally.
My days started with valve bases with side connections, no soldering.
When I retired most of the connections in the equipment were multiple Male and female connectors, which caused all sorts of problems, little or no soldered connections.
Just one final thought I suppose a fibre optic coupler is also a connection, by definition.
Cheers
John

martin_m0nxp · 27th Aug 2018, 10:36 pm

On a related note to this - when I was young (around 14 or 15 I think) I was repairing a faulty handheld LCD game of the type that were very popular in the late 80s - I think the original fault was a broken battery connector or similar. Having fixed the issue I, for some reason, decided to clean everything with some form of contact cleaner. When the cleaner came into contact with the zebra strip it started expanding - after a couple of minutes it was about 3 times the length it was supposed to be!

Not sure what component of the cleaner it was that caused the reaction, but since then I've avoided letting any liquid come into contact with them.

Refugee · 28th Aug 2018, 12:10 am

I think it was carbon tetracloride that used to make rubber double in size and go all sticky.

julie_m · 28th Aug 2018, 12:51 am

They're a fiendishly clever idea. Same principle as a laminated core for a transformer: conducts transversely, but not longitudinally. As long as there is at least one conducting layer between each corresponding pair of contacts on the PCB and the LCD, and at least one insulating layer in the space between them, it will Just Work. And in practice, the layers in the strip are much narrower than the metallised contact pads; so there are several "used" ones connecting pairs of pads on the PCB and LCD, and a few "unused" ones in the spaces between pads. Care must still be taken not to over-compress them too much, lest they become deformed enough to mis-connect.

John10b · 28th Aug 2018, 3:45 pm

I ruined a Bush Bakeolite cabinet using carbon t... when I was serving my apprenticeship, a hard lesson learned about that stuff, which nearly got me the sack, but fortunately I had a very understanding boss.
Cheers
John

Lloyd 1985 · 28th Aug 2018, 5:58 pm

If you’re interested in another way of connecting up LCD’s, how about a plastic ribbon cable? I worked for a place making digital water meters back in 2004, where I had to operate a machine that stuck the ribbon to the lcd and then to the pcb, the ribbon was as thick as a piece of sellotape, but had black and white lines on it, the black bit I guess was carbon, as that was the conductive bit. You can find the same type of connection in some calculators too.

So back to the machine, you placed an LCD in one side of the machine with the ribbon on top of it, lined t up on a little monitor at the side of the machine, then pressed 2 buttons either side of the machine, the LCD and ribbon disappeared Into the machine and a heated strip of rubber applied pressure to the assembly for a few seconds, this melted the adhesive on the ribbon and bonded it to the LCD. You then got another one you made earlier and put it in the other side of the machine along with the PCB, pressed the same 2 buttons and that would disappear into the machine and get pressed on, at the same time the LCD you put in previously came out of the machine, and you would remove it and set up the next one. I sat operating that machine for months! And I tell you it was the most boring job I have ever had!!!

Regards
Lloyd

Jon_G4MDC · 28th Aug 2018, 9:26 pm

Tell Yaesu about that for the FT857 and FT897 displays.
They have a folded ribbon cable so attached.

Lucky if you have one which does not have dead vertical stripes in the display due to failure of same.

25th Aug 2018, 3:42 pm	#21
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Elastomer Strips Do you mean how many ways to use elastomer strips, or electrical connections in general?

25th Aug 2018, 4:46 pm	#22
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Elastomer Strips I was just wondering how many ways generally. My days started with valve bases with side connections, no soldering. When I retired most of the connections in the equipment were multiple Male and female connectors, which caused all sorts of problems, little or no soldered connections. Just one final thought I suppose a fibre optic coupler is also a connection, by definition. Cheers John

27th Aug 2018, 10:36 pm	#23
martin_m0nxp Retired Dormant Member Join Date: Jul 2018 Location: Southampton, Hampshire, UK. Posts: 31	Re: Elastomer Strips On a related note to this - when I was young (around 14 or 15 I think) I was repairing a faulty handheld LCD game of the type that were very popular in the late 80s - I think the original fault was a broken battery connector or similar. Having fixed the issue I, for some reason, decided to clean everything with some form of contact cleaner. When the cleaner came into contact with the zebra strip it started expanding - after a couple of minutes it was about 3 times the length it was supposed to be! Not sure what component of the cleaner it was that caused the reaction, but since then I've avoided letting any liquid come into contact with them.

28th Aug 2018, 12:10 am	#24
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Elastomer Strips I think it was carbon tetracloride that used to make rubber double in size and go all sticky.

28th Aug 2018, 12:51 am	#25
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Elastomer Strips They're a fiendishly clever idea. Same principle as a laminated core for a transformer: conducts transversely, but not longitudinally. As long as there is at least one conducting layer between each corresponding pair of contacts on the PCB and the LCD, and at least one insulating layer in the space between them, it will Just Work. And in practice, the layers in the strip are much narrower than the metallised contact pads; so there are several "used" ones connecting pairs of pads on the PCB and LCD, and a few "unused" ones in the spaces between pads. Care must still be taken not to over-compress them too much, lest they become deformed enough to mis-connect. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

28th Aug 2018, 3:45 pm	#26
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Elastomer Strips I ruined a Bush Bakeolite cabinet using carbon t... when I was serving my apprenticeship, a hard lesson learned about that stuff, which nearly got me the sack, but fortunately I had a very understanding boss. Cheers John

28th Aug 2018, 5:58 pm	#27
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,819	Re: Elastomer Strips If you’re interested in another way of connecting up LCD’s, how about a plastic ribbon cable? I worked for a place making digital water meters back in 2004, where I had to operate a machine that stuck the ribbon to the lcd and then to the pcb, the ribbon was as thick as a piece of sellotape, but had black and white lines on it, the black bit I guess was carbon, as that was the conductive bit. You can find the same type of connection in some calculators too. So back to the machine, you placed an LCD in one side of the machine with the ribbon on top of it, lined t up on a little monitor at the side of the machine, then pressed 2 buttons either side of the machine, the LCD and ribbon disappeared Into the machine and a heated strip of rubber applied pressure to the assembly for a few seconds, this melted the adhesive on the ribbon and bonded it to the LCD. You then got another one you made earlier and put it in the other side of the machine along with the PCB, pressed the same 2 buttons and that would disappear into the machine and get pressed on, at the same time the LCD you put in previously came out of the machine, and you would remove it and set up the next one. I sat operating that machine for months! And I tell you it was the most boring job I have ever had!!! Regards Lloyd

28th Aug 2018, 9:26 pm	#28
Jon_G4MDC Nonode Join Date: Nov 2015 Location: Welwyn Garden City, Hertfordshire, UK. Posts: 2,015	Re: Elastomer Strips Tell Yaesu about that for the FT857 and FT897 displays. They have a folded ribbon cable so attached. Lucky if you have one which does not have dead vertical stripes in the display due to failure of same.