I was going through my components bin last night and for some reason this was placed in my speaker/mic drawer. I am almost positive this is neither. After a few hours of browsing the internet for answers I turn to the hardware gurus in this forum. Does anyone have any idea what this sensor is?
Sorry about the picture quality, I only have my phone on me at the moment. Just in case it can't be read easily, the component has "54J5" written on the black sticker on the front followed by some symbol I can't identify (possibly the manufacturer). The sides are unmarked, and the back is the same.
I tried to get a pic of the back, but it wasn't very good. There are 4 pins, 2 thinner and 2 thicker. The thin ones are the same height, and the thick ones are 2 different heights (probably doesn't mean much as it was reclaimed from some board years ago, dont remember what it was though). The only weird thing is that the thin and thick pins are soldered together. Does anyone have any ideas? I'd love to use this, I just need to find a datasheet so I can get the pinout and voltages!
MarkT:
Have you tried measuring the impedance? It looks most like an electret microphone.
I had attempted this earlier and got no result (or at least one I cannot fathom). When I measured impedance on this I got an infinite result (my meter just displays a 1 on the left hand side when something is infinitely high or low or just out of range). I tried several ranges, but I've never seen a speaker outside of the 2-16ohm range, I assume mics are the same? To double check myself I checked the impedance on an 8ohm speaker and got 7.8ohms, so I know I measured it right. I'm perplexed, personally.
I see 4 pins, 2 seperation with 2 pins. I do agree with MarkT assumtion.
To confirm :
First... Do you have a scope ? If you do... put a 10 K resistor , connect one of the pins set, and the other pins set goes to a gnd. Put a voltage, like 3 V, using 2 AA or any 1 1/2 V battery, place the positive at the resistor, the negative at the GND. Connect your scope probe at the pins connect to the resistor and ground the probe. Scope setting is about 10 mV/div and 0.1 mS/div.
And see what happen... If it is a "mic", you will get a "sound wave"... blow air on it and see what happen... Big waveform... yes ? than it is a "electret mic".
