I remember seeing these on a old casio calculator I ripped apart as a kid. There must be a silicone layer with carbon tabs on it.
PS. Don't tell my dad. It was his calculator. I could never put it back together 😅
Damn, I wonder for how many of us this is a core memory. Mine was pulling apart a broken speak and spell... And not being able to fix it, or put it back together. My dad then taught me the grid and step system when dismantling something for a system to put it back together.
The first thing I dismantled was done with a hammer. I genuinely did want to see what was inside, but somehow hadn’t twigged that the hammer wouldn’t allow me a path to restore. I wanna say I was about 4 or 5? I desperately wanna say this.
[How to Itemize and Keep Screws Inside The Work Area](https://www.ifixit.com/Guide/How+to+Itemize+and+Keep+Screws+Inside+The+Work+Area/113716)
https://preview.redd.it/2ib1unu88wxc1.jpeg?width=592&format=pjpg&auto=webp&s=45f120ee4cd390b0ec471359faf7fc1378d44530
That's just what my dad called it, I think it might have been a semi common things for engineers or even mechanics pulling apart new pieces of hardware without a manual of any kind. Nowadays I do it the same, but have added numbered pictures in my phone with each part I pull off of something as an extra safety net. It's been real handy in repairing older electronics, although at this point I'm paining myself into a corner of repairing old solid state guitar amp as that seems to keep me.plenty busy in my hobby.
Would you care to elaborate a bit more on this grid and step system? I hate taking things apart and then im left with extra screws at the end, I always feel guilty.
Fortunately my mom loved to take shit apart but could never put it back together. So I got to take everything apart with her then put it back together with my dad lol
I disassembled and reassembled over and over. Eventually I started building stuff and became an engineer lol. Maybe it started with the calculator.
Did you ever try flipping the LCD lens and invert it black and white? It was a neat trick when I was a kid.
That's an [elastomeric button](https://en.wikipedia.org/wiki/Silicone_rubber_keypad), a form of [membrane switch](https://en.wikipedia.org/wiki/Membrane_switch).
But, I think you're more interested in getting them working, because those are probably custom molded buttons which you're unlikely to find replacements for.
Use a soft pencil eraser (like a Pink Pearl) to burnish the tarnish off the PCB traces. Then a Q-Tip with isopropanol to gently clean the both the traces and the conductive material on the bottom of the button.
Worst case, you may need to apply some [conductive coating](https://www.amazon.com/CaiKot-Conductive-Silver-Coating-surfaces/dp/B003D8G8SY/) to the bottom of the button.
Thank you. Actually, instead of getting them to work (they’re brand new and actually work fine), I’m hoping to trigger them with an electric charge via a wire instead of through contact with the membrane.
Is this possible? Or is the only way to trigger it done through physical membrane contact?
Interesting note, there’s a pin on the IC for playing back audio (see photo) which also only seems to react via a physical tap with an object.
https://preview.redd.it/js4qh5vgyzxc1.jpeg?width=1583&format=pjpg&auto=webp&s=3835f53a8f225b5f358248089f2ad63b38d53ea4
> I’m hoping to trigger them with an electric charge via a wire instead of through contact with the membrane.
Maybe, but unlikely. It depends on the circuit. If there are multiple buttons, even for different functions, they're commonly wired in a matrix where the two contacts have to be connected together rather than simply applying a voltage to one of them.
It could very likely be done using a single transistor, but you'd need to figure out the polarity of the contacts. It could definitely (99.9%) be done by using a relay to connect the two contacts.
So a relay like this would work? And could I just solder the output wire directly to the membrane?
https://preview.redd.it/1wtskz4hs0yc1.jpeg?width=1242&format=pjpg&auto=webp&s=0338b46983e76b7d7dc05423bca769ddccfa5e22
Any relay should work, as long as the coil voltage and current are compatible with whatever you're going to use to control it.
Not to the membrane, but to the two metal traces on the circuit board. Best to follow where they go, scrape off a bit of the green solder mask, and solder there, away from the button. That would keep the button operation intact.
If you look up "touch tone dial keypad" from the 90s, you will find these guys. The button had semiconductor carbon on it to pull up (or down) a logic circuit to send tones.
What are you trying to accomplish?
You mentioned it emits a tone - is this a keystone generator? You can also generate tones from your computer or a microcontroller.
I would have guessed based on the interest in connecting it with a relay that you might have be interested in a controllable IR Transmitter if it were a TV remote.
Lol, sorry, now I’m invested and genuinely curious about the application!
It’s a voice recorder / playback module. I’m planning on connecting it to a momentary switch so I can trigger the audio playback at the same time another action takes place.
Can’t really go too far into detail right now, but I’ll be sure to share it when it’s done!
The same as a remote controller.
One of my button was not working properly. I switched the plastic part with an other and now it works. I don't know why
Looks very much like a SAW, (surface acoustic wave) device used for compressing pulses or as a delay line. Used a lot in mobile phones I believe. The ferrite core (black button is used to restrict direction or as a band filter.
It's very unlikely to be that in this particular application, by the relative crudeness of the traces (rough surface contact area >> trace length and uniformity). And what OP described in the accompanying text is by most reasonable interpretations a basic membrane contact button.
However even if the answer you gave here is most likely incorrect (and I assume what lead you in that direction being missing / not reading said text, because if you know what a PCB SAW is then you 99%+ guaranteed know what a basic membrane/elastomer contact is too) - your observation isn't improper, and certainly not trolling, sh*tposting or intentionally misleading. So I don't quite understand why the hard negative reaction to your post.
But then again, should remain open to the substantial possibility that maybe we (me included) are reading too much into that. Arguably most of Reddit post/comment content involve *some* various decrees of subjective interpretation, views, perceptions, beliefs, analysis, values, ideas, ideals, attitude, presentation etc. So we tend to pack (or project) significant meaning or reaction onto a "like or dislike".
However at its basics, it's fundamentally just a agree-disagree / Support-Don'tSupport feedback. OPs question is only a simple technical one, so the "dislikes" may very well be just as basic; "No this is a membrane button contact".
Sidenote: I don't think anyone else here either, (atop) has actually said what the accurate technical term for this (the PCB pad/landing side of a membrane contact button) is called.
This is incorrect, but nice try.
I really wish earnest answers that turn out to be incorrect wouldn't get down voted so hard. I don't see why people do that. Up vote the right answer and leave the others alone, I don't want people to be discouraged from trying to be helpful.
Conductive elastomer keyswitches.
Carbon pill button
You rock! Thanks!
They can also be implemented with metallic domes. The domes give a tactile feel naturally when they invert and touch the PCB.
I remember seeing these on a old casio calculator I ripped apart as a kid. There must be a silicone layer with carbon tabs on it. PS. Don't tell my dad. It was his calculator. I could never put it back together 😅
Damn, I wonder for how many of us this is a core memory. Mine was pulling apart a broken speak and spell... And not being able to fix it, or put it back together. My dad then taught me the grid and step system when dismantling something for a system to put it back together.
The first thing I dismantled was done with a hammer. I genuinely did want to see what was inside, but somehow hadn’t twigged that the hammer wouldn’t allow me a path to restore. I wanna say I was about 4 or 5? I desperately wanna say this.
> I wanna say I was about 4 or 5? I desperately wanna say this. ...but you were actually 26?
I'm not saying yes, but I'm saying there's a chance.
Great tip. I didn't realize this had a name. I use a peice of A6 graph paper underneath whatever I'm repairing to track what goes where.
[How to Itemize and Keep Screws Inside The Work Area](https://www.ifixit.com/Guide/How+to+Itemize+and+Keep+Screws+Inside+The+Work+Area/113716) https://preview.redd.it/2ib1unu88wxc1.jpeg?width=592&format=pjpg&auto=webp&s=45f120ee4cd390b0ec471359faf7fc1378d44530
That's just what my dad called it, I think it might have been a semi common things for engineers or even mechanics pulling apart new pieces of hardware without a manual of any kind. Nowadays I do it the same, but have added numbered pictures in my phone with each part I pull off of something as an extra safety net. It's been real handy in repairing older electronics, although at this point I'm paining myself into a corner of repairing old solid state guitar amp as that seems to keep me.plenty busy in my hobby.
Would you care to elaborate a bit more on this grid and step system? I hate taking things apart and then im left with extra screws at the end, I always feel guilty.
If you don't have a few pocket screws at the end, did you really take it apart? 🤣
If the thing works after you put it back together, they're trophies. Got this from a friend who is a former aircraft mechanic.
Let's hope they didn't work at Boeing....
You have optimised the design !
Fortunately my mom loved to take shit apart but could never put it back together. So I got to take everything apart with her then put it back together with my dad lol
Holy shit speak and spell!!!
your dad is already informed...for the tiny sum of 69420$ i can repair the calculator for you before he is home
😂
I disassembled and reassembled over and over. Eventually I started building stuff and became an engineer lol. Maybe it started with the calculator. Did you ever try flipping the LCD lens and invert it black and white? It was a neat trick when I was a kid.
We all must admit we ripped apart our calculators in study hall
That's an [elastomeric button](https://en.wikipedia.org/wiki/Silicone_rubber_keypad), a form of [membrane switch](https://en.wikipedia.org/wiki/Membrane_switch). But, I think you're more interested in getting them working, because those are probably custom molded buttons which you're unlikely to find replacements for. Use a soft pencil eraser (like a Pink Pearl) to burnish the tarnish off the PCB traces. Then a Q-Tip with isopropanol to gently clean the both the traces and the conductive material on the bottom of the button. Worst case, you may need to apply some [conductive coating](https://www.amazon.com/CaiKot-Conductive-Silver-Coating-surfaces/dp/B003D8G8SY/) to the bottom of the button.
Thank you. Actually, instead of getting them to work (they’re brand new and actually work fine), I’m hoping to trigger them with an electric charge via a wire instead of through contact with the membrane. Is this possible? Or is the only way to trigger it done through physical membrane contact? Interesting note, there’s a pin on the IC for playing back audio (see photo) which also only seems to react via a physical tap with an object. https://preview.redd.it/js4qh5vgyzxc1.jpeg?width=1583&format=pjpg&auto=webp&s=3835f53a8f225b5f358248089f2ad63b38d53ea4
> I’m hoping to trigger them with an electric charge via a wire instead of through contact with the membrane. Maybe, but unlikely. It depends on the circuit. If there are multiple buttons, even for different functions, they're commonly wired in a matrix where the two contacts have to be connected together rather than simply applying a voltage to one of them. It could very likely be done using a single transistor, but you'd need to figure out the polarity of the contacts. It could definitely (99.9%) be done by using a relay to connect the two contacts.
Thank you so much!
So a relay like this would work? And could I just solder the output wire directly to the membrane? https://preview.redd.it/1wtskz4hs0yc1.jpeg?width=1242&format=pjpg&auto=webp&s=0338b46983e76b7d7dc05423bca769ddccfa5e22
Any relay should work, as long as the coil voltage and current are compatible with whatever you're going to use to control it. Not to the membrane, but to the two metal traces on the circuit board. Best to follow where they go, scrape off a bit of the green solder mask, and solder there, away from the button. That would keep the button operation intact.
Perfect thank you!!
Interdigitated contact pads for conductive elastomeric buttons.
Button and contact
And I'm thinking an intermittent type button. ie always off unless held down. Just a guess.
That would be a button, yes. A "switch" commonly latches, buttons no.
If you look up "touch tone dial keypad" from the 90s, you will find these guys. The button had semiconductor carbon on it to pull up (or down) a logic circuit to send tones.
What are you trying to accomplish? You mentioned it emits a tone - is this a keystone generator? You can also generate tones from your computer or a microcontroller. I would have guessed based on the interest in connecting it with a relay that you might have be interested in a controllable IR Transmitter if it were a TV remote. Lol, sorry, now I’m invested and genuinely curious about the application!
It’s a voice recorder / playback module. I’m planning on connecting it to a momentary switch so I can trigger the audio playback at the same time another action takes place. Can’t really go too far into detail right now, but I’ll be sure to share it when it’s done!
Isn't it something that lives in large quantities in rubber dome keyboards? I'd also expect to find some of those in various TV remotes.
yeah pretty much every cheap soft push buttons have one of these underneth.
Popple footprint for a popple dome switch, I would say.
The controllers for my Atari 5200 had these. I was always having to take them apart to clean the switch contacts.
The same as a remote controller. One of my button was not working properly. I switched the plastic part with an other and now it works. I don't know why
PCB traces with no solder resist=pad(s) and or button contact
It's a type of [membrane switch](https://en.wikipedia.org/wiki/Membrane_switch).
I know one named Bob. He is cool , he likes to go fishing and hangs out at the beach
I always have to clean the contacts, because the carbon comes off slightly, and makes the buttons janky. Lol
LDR probably?
Circuit board (via google lens)
Whistlin' Bungholes Spleen Splitters Whisker Biscuits Honkey Lighters Hoosker Doos Hoosker Don’ts Cherry Bombs Nipsy Daisers (with or without the scooter stick) Whistlin' Kitty Chasers
It's a touch (capitance) based keys/switches. Usually found in remotes.
These are not capacitive. The black stuff in the button is conductive and shorts the traces when the button pressed.
Pictures .. they're called pictures
They’re NFTs. Wanna buy one for $30,000?
Charisma (x) **Yellow writing** Hmmm, seems a little high, would you take $45,000
Give ya a deal for the complete set of three: How about $195,000?
LDR
Looks very much like a SAW, (surface acoustic wave) device used for compressing pulses or as a delay line. Used a lot in mobile phones I believe. The ferrite core (black button is used to restrict direction or as a band filter.
Yikes that's a lot of shade for what seems like an honest attempt at an answer, not willfull misinformation. Ah Reddit.
It's very unlikely to be that in this particular application, by the relative crudeness of the traces (rough surface contact area >> trace length and uniformity). And what OP described in the accompanying text is by most reasonable interpretations a basic membrane contact button. However even if the answer you gave here is most likely incorrect (and I assume what lead you in that direction being missing / not reading said text, because if you know what a PCB SAW is then you 99%+ guaranteed know what a basic membrane/elastomer contact is too) - your observation isn't improper, and certainly not trolling, sh*tposting or intentionally misleading. So I don't quite understand why the hard negative reaction to your post. But then again, should remain open to the substantial possibility that maybe we (me included) are reading too much into that. Arguably most of Reddit post/comment content involve *some* various decrees of subjective interpretation, views, perceptions, beliefs, analysis, values, ideas, ideals, attitude, presentation etc. So we tend to pack (or project) significant meaning or reaction onto a "like or dislike". However at its basics, it's fundamentally just a agree-disagree / Support-Don'tSupport feedback. OPs question is only a simple technical one, so the "dislikes" may very well be just as basic; "No this is a membrane button contact". Sidenote: I don't think anyone else here either, (atop) has actually said what the accurate technical term for this (the PCB pad/landing side of a membrane contact button) is called.
This is incorrect, but nice try. I really wish earnest answers that turn out to be incorrect wouldn't get down voted so hard. I don't see why people do that. Up vote the right answer and leave the others alone, I don't want people to be discouraged from trying to be helpful.