Indicator light buzzer

[Sleeper]

Dear All
As I'm that age and new to MMs, what I need is sounder across the indicator lamp to remind me that I don't have self-cancelling indicators ( have been a few near misses due to my stupidity and people expecting me to turn as I approach their junction ).
I dug into my box of electronic bits and fitted a mini sounder ( smaller than a sixpence ) across the bulb an hey presto a warning note,,,,but only on right turns...it seems that the bulb is illuminated by different polarity 12volts for different directions...
Anyone know of a small 12v sounder that is not polarity conscious ??

Thanks
John

[BrianHawley]

You could make a bridge with four small diodes or rectifiers and use the one you've got.

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The AC here is from your bulb. The rectifiers need to handle at least 12v. If it's a piezoelectric buzzer, the current shouldn't be a worry.

[Sleeper]

Brian
Thank you , now , shall I use four diodes or a small bridge? Have to look in the shed and see what I've got..

Once again thanks

John

[oliver90owner]

Fit two?

[palacebear]

I was going to claim naive logic and suggest the same thing.
One each on left and right switch outputs...?

[BrianHawley]

Brian
Thank you , now , shall I use four diodes or a small bridge? Have to look in the shed and see what I've got..

Once again thanks

John

Could use either. A single piece bridge is effectively four rectifiers in a single encapsulation.

I'm assuming here you are right about the polarity reversing depending on the direction of indication. I hadn't heard that. Must have a look at the circuit diagram if I can find it.

[Sleeper]

OK , fit two ( piggy-back ) ... now there's an option...maybe simpler than a bridge , and I have a bag of them..
I'll let you know..

It must be reversed polarity on the older MMs indicator system , haven't looked at the diagram yet just assumed it

John

[BrianHawley]

Possibly we are on the wrong track guys.

The only circuit diagrams I've got show one side of the warning light is always earthed and the same voltage applied to the other side to light it, regardless of indication direction. This means that unless OP's car is different (might be if it's an early car) , the voltage to the light is NOT reversed and diodes won't help.

Why does the buzzer only work in one indicator direction? First are we getting power both directions? Does the bulb light up both ways? If it does, then it must be voltage (measure it). I guess blown bulbs or bad wiring could make one side different from the other.

[Sleeper]

SORTED

One buzzer, two back to back, with pigtails

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Soldered

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and tucked up out of the way

2017_0708indicatorbuzzer0004.JPG (91.03 KiB) Viewed 2233 times

suppose I should measure the polarity just to answer the question??

John

[Sleeper]

"Why does the buzzer only work in one indicator direction? First are we getting power both directions? Does the bulb light up both ways? If it does, then it must be voltage (measure it). I guess blown bulbs or bad wiring could make one side different from the other."

Just double checked and the polarity does reverse with the change of direction....must find an appropriate wiring diagram and found out how it works..

John

[BrianHawley]

"Why does the buzzer only work in one indicator direction? First are we getting power both directions? Does the bulb light up both ways? If it does, then it must be voltage (measure it). I guess blown bulbs or bad wiring could make one side different from the other."

Just double checked and the polarity does reverse with the change of direction....must find an appropriate wiring diagram and found out how it works..

John

Ah ha! So the earlier cars ARE different.

You learn something ever day in this hobby.

Glad you got it sorted. Looks like a nice neat job.