Purpose: Silence your digital watch beeps and alarms. Following this modification, your digital watch will be permanently silent.

Method: Remove spring-diaphragm amplification

Target audience: This is especially useful for standardized test takers (MCAT, SAT, LSAT, GRE, etc.) and others who need the element of surprise in whatever they are timing.

Step 1: Get a cheap watch somehow

I paid the kind folks at the Walmart jewelery counter a visit. I traded my $9 for this fine Casio watch.

Perhaps you can find a digital watch around the house.
actually the back plate is a piezo sounder, not a diaphragm. its is the thing making the sound, the spring is only the electrical contact. so all this does is disables the piezo by removing said contact. <br>so its not a &quot;experimental prototype Skunkworks F-117 watch&quot; its a watch with a disabled piezo ;)
I wrote this all up as diabling the piezo but then I couldn't figure why it was a piezo if it had no electrical activity. I deduced that the spring just buzzed that piece and amplified it where a piezo should be turning it into a voltage. I didn't think there could be a speaker behind that plate.
its because that plate (the metal backplate and the ceramic disk together) are the speaker, the spring is the + and the connection where the backplate touches the metal on the watch workings (normally a bit bent up) is the - (or the other way round, probably doesn't matter X3 ).. <br>also did u know a piezo speaker/sounder can act as a knock sensor? its what they use in electronic drum kits :)
So piezo is grounded to the backplate and the spring drives it (or other way around like you say). I think the piezo still is a surface that acts like a diaphragm to amplify the sound though right? When I put my ear near the watch after removing the spring I can still hear an extremely quiet beep... <br> <br>Like an automotive knock sensor? That's pretty cool about electronic drum sets
yea but the whole thing, as in the backplate, is the piezo, the spring is just the wire for it. its probably better to look up piezo's on wiki or something that wil give u a much better explanation than i can X3 <br> <br>in short a piezo is made up of ceramic disk on a metal plate normally a thin disk of brass or something, <br>there is no speaker behind the ceramic since the ceramic and the metal plate are the speaker itself. the metal is the negative side, and is wired thus, and the ceramic is the positive and is wired accordingly, connect it up to any sound source and u will hear it, wont be too good tho since its high range. <br> <br>another use for piezo is in inkjet printers, the print head has tiny piezos in them that pulses to send the ink droplets onto the paper.. the pulse forces the ink out the nozzle.

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