using microbit as a relay

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tate2326
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using microbit as a relay

Post by tate2326 » Tue Jul 18, 2017 9:10 pm

I'm needing to use the microbit to allow me to turn on/off a 12v speaker/horn. Any ideas the wiring on this? Or is this even possible?

thanks

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deshipu
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Re: using microbit as a relay

Post by deshipu » Wed Jul 19, 2017 7:37 am

Everything is possible, given enough time and budget. You can follow those instructions, replacing the Arduino with a MicroBit: http://www.instructables.com/id/Connect ... o-Arduino/

tate2326
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Re: using microbit as a relay

Post by tate2326 » Sun Jul 23, 2017 1:47 am

Anyone know how to get ahold of Monk Maker? He has a microbit relay but no way to purchase it...

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pythoncoder
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Re: using microbit as a relay

Post by pythoncoder » Mon Jul 24, 2017 12:37 pm

If you gave us some detail on the thing you're trying to drive it would help. Do you have a webref for it? If not, how much current does it use? You may only need a transistor and a resistor but without details it's hard to make a recommendation.
Peter Hinch
Index to my micropython libraries.

tate2326
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Re: using microbit as a relay

Post by tate2326 » Fri Jul 28, 2017 10:56 pm

I'm wanting to turn on/off a 12v horn. The horn will use a 12v car battery. I'll prob start off with the microbit running on 2 AA batteries but eventually want the microbit to run off the car battery too. I'll need to figure out how to step 12v down to 5v or 3v....

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dhylands
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Re: using microbit as a relay

Post by dhylands » Sat Jul 29, 2017 6:54 am

Pololu makes a wide variety of switching step-down voltage regulators which will convert 12v to 5v or 3.3v.
https://www.pololu.com/category/131/ste ... regulators

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pythoncoder
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Re: using microbit as a relay

Post by pythoncoder » Sat Jul 29, 2017 9:34 am

For us to make suggestions on driving the horn we need to know how much current it draws. If you're talking about a car horn I seem to recall that they take many amps.
Peter Hinch
Index to my micropython libraries.

daveclarke
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Joined: Sat Jun 26, 2021 7:36 am

Re: using microbit as a relay

Post by daveclarke » Sat Jun 26, 2021 7:46 am

I realise this is an old post but I'm looking to connect a microbit to a horn of some sort. The context of this is starting yacht races. There are expensive commercial "computers" for doing this that aren't always reliable. For training/coaching I need something simple. I can code the microbit but I need to figure out how to generate a loud noise like from an airhorn. Ideally a sealed 12 volt lead acid connected to maybe a carhorn from a wreckers would do the trick. Any assistance appreciated.

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