Is it possible to make an buzzer that sounds with wrong polarity?

If its possible. How can i make an buzzer sound if i connects to wires in wrong polarity with an arduino?

What sort of a buzzer are we talking about here?

Use a bridge rectifier upstream of the buzzer , with the buzzer connected to the dc output side .

Bjerknez:
If its possible. How can i make an buzzer sound if i connects to wires in wrong polarity with an arduino?

It sounds like you have already soldered it in, or is there a good reason why you don’t simply correct the wiring? Some errors have a chance of being corrected in software (mixing some pins where the pins are mappable) but some not like soldering a diode in the wrong way round. If both pins of the buzzer go to directly to dedicated GPIO pins on an MCU, which would be unusual, you have a chance.

If its possible. How can i make an buzzer sound if i connects to wires in wrong polarity with an arduino?

Maybe... We need more details.

If you reverse the power connections to an Arduino, or if you apply negative voltage to a pin you can fry the Arduino.

Ok, let me explain.

Lets say i have an pcb and want to make my own "power supply". 9v input, an buck converter that reduce the voltage to 5v and 5v in to a microcontroller.

When i power the sircuit with right polarity all is good of course, but if i reverse the polarity, i want an warning sound from anstandard 5v buzzer. Active or passive. Or a led diode that lights up red etc.

Buzzer in series with diode. :grinning:

A simple P-channel mosfet can be used to prevent damage from reversed polarity without having any voltage drop penalty. If you want a visual indication, use a power on led. It’s failure to light will alert the user to a problem. If you really do want a buzzer, wire it with a series diode to allow it to operate only with reversed polarity, but combine this with another method of protecting the circuit.

Edit.
Crossed with Paul__B

Since the OP never said what "buzzer" he wants to use, we're only guessing. In fact, I rather doubt the "buzzer" is a buzzer, but a piezoelectric audio transducer.

THIS is a buzzer. It runs on 24VAC and would likely fry any Arduino you attach it to.

buzzer.jpg

If you Google "buzzer" you will get hundreds of piezo audio transducers because that's the search term people who have never seen a buzzer before will use.

buzzer.jpg

SteveMann:
Since the OP never said what "buzzer" he wants to use, we're only guessing. In fact, I rather doubt the "buzzer" is a buzzer, but a piezoelectric audio transducer.

THIS is a buzzer. It runs on 24VAC and would likely fry any Arduino you attach it to.

buzzer.jpg

If you Google "buzzer" you will get hundreds of piezo audio transducers because that's the search term people who have never seen a buzzer before will use.

I mentioned that in post #5.

I'm most courius about how i can do this, and i have no reasons. I want to learn more about electronics and thats why i make my self scenarioes before i ask and try my self.

I have tried bridge rectifier with four diodes and that works fine, but since we do nothing wrong when "reversing" the polarity, no warning is needed.

Buzzer in series with diode. Anode of diode to negative line so that if this becomes positive due to reverse connection, the diode conducts and the buzzer sounds.

eBay

If you can afford a voltage drop of 0.4 volts, you could also, as an alternative, use a series Schottky diode. If not, I suppose you could also wire a fat diode, reversed, across the power rails. The smoke pouring off melting insulation etc. would effectively alert the user to a connection error. Or combine the shorting diode with a fuse, optionally a PTC resettable fuse.

This is quite a well presented but informal lecture on circuit protection: Low Cost Reverse Polarity and Over Current Protection (Corrected) - YouTube . The woman giving it also achieve fame for fabricating mosfets in a simple home lab.

I'd suggest that if the circuit is susceptible to damage from applying reverse polarity power, it will likely happen quickly enough that the buzzer will just be audio confirmation that the device has been fried.

In practice it might be a better use of one's time to implement a protection scheme to prevent damage from reversed polarity.

Yeah, well I was just answering the question "buzzer that sounds with wrong polarity?". :stuck_out_tongue_closed_eyes:

Paul__B:
Yeah, well I was just answering the question "buzzer that sounds with wrong polarity?". :stuck_out_tongue_closed_eyes:

I'm not faulting anyone for answering the question that was asked, I'm just suggesting that taping a battery-powered smoke detector to the board might be one approach to making a buzzer sound when the wrong polarity is applied. Further, if a smoke detector is a plausible answer to an electronics design question, perhaps it is time to reconsider the system requirements.

MrMark:
if a smoke detector is a plausible answer to an electronics design question, perhaps it is time to reconsider the system requirements.

Lucas_Smoke.jpg

Lucas_Smoke.jpg

Does it come with the inserter?

It is available in positive earth too!

Apparently, the way that it is used is by reversing the battery polarity. Release the smoke from the jar and it gets sucked back into the wiring. It also guarantees that you will never again have any trouble with that equipment.