Add a buzzer to a multimeter?

hello,
is it possible to add a continuity check buzzer to this MAS830S mutimeter ?

i would like to do like on this video but i cant find which resistor is the good one
http://www.youtube.com/watch?v=ItqYUUjcwfk

i don't care if the buzzer is inside or not
thanks

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framistan4 years ago
I looked at the video you suggested of the Mexican speaking person doing the mod. I don't speak Spanish, but it looks like he is using the DIODE TEST setting on the meter to also activate a piezo buzzer. You might be able to copy what he did by clicking your meter to "DIODE TEST" function. Then take your PLUS and MINUS probes and plug them into the normal jacks (don't plug into the amps jack). connect the plus probe tip to the negative clip and the meter should read close to zero ohms. Now, attach your sonalert black wire to the common jack. Use the red wire of the sonalert to touch various resistors until you find one that makes the buzzer buzz. Make sure it STOPS buzzing when you un-connect your redprobe from the black probe. If the buzzer doesn't stop buzzing, then keep looking for a spot where it BUZZES when probes are touching, but STOPS when the probes stop touching (each other). KEEP IN MIND THAT THIS SUGGESTION IS POSSIBLY DANGEROUS TO YOUR METER AND MAY DESTROY IT BEFORE YOU FIND THE RIGHT SPOT.

Another idea, is to disconnect the foil trace going to your 10Amp Jack. Now just wire the sonalert buzzer to the battery for power and use the amps probe for your buzzer test. The AMPS test is not hardly EVER used anyway... and in fact, many times if the amps test is done wrong you may blow meter fuses ..... so therefore, loosing the ten amps function is no real loss anyway. Whenever you want to do a BUZZER / continuity test, just plug your red probe into the 10AMP jack.
rastactivist (author)  framistan4 years ago
thanks i did the second solution it works fine
DmitryS3 years ago

I have the same unit and I was pursuing the same idea. The only solution I have found is attaching the negative terminal to the fuse (opposite side to where the F is printed) and positive terminal to the right side of R4 resistor.

The first problem with this approach is that since there are no chips to produce the buzz I had to drive an external PCB taken from a musical greetings card. Because it was a *Happy Birthday* card I had to use a 555 timer in order to limit HIGH state of the buzzer to 150 ms and create a delay of 350 ms in the LOW state, which resulted in similar audible tone as the classical continuity tester produces.

Second problem is that with this mod not only the diode tester becomes a continuity tester, but a 2K resistance tester as well .. so If you want you can add a switch or something preventing it from beeping when you actually need the 2K range resistance tester.

Is it possible? Yes
Is it something we could easily walk you through to make it happen? Probably not.
If done will it fit inside the meter's case? Probably not.

Is it beyond my expertise? Most definitely.
rastactivist (author)  mpilchfamily4 years ago
i would like to do like on this video but i cant find which resistor is the good one
http://www.youtube.com/watch?v=ItqYUUjcwfk

i don't care if the buzzer is inside or not