Hobbs meter

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stephane130281
Posts: 11
Joined: Sun Aug 07, 2022 9:54 pm

Hobbs meter

#1 Post by stephane130281 »

Dear all,

Before burning my Leobodnar card, I d like to ask for advice.
I connected my hobbs meter on a 12V DC power supply.
But I d like to be able to turn it on using the battery switch.
By battery switch is currently connected to the leobodnar card to be able to give the output to xplane and turn the battery on and off in XPlane 11.

How can I safely connect the 12V power supply to the battery switch without risking damaging the leobodnar card that will see the 12V current?
Can I simply connect the switch on the ground to close and open the 12V supply to the hobbs meter?

Thanks for your help.

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jph
Posts: 2030
Joined: Fri Apr 10, 2020 12:50 pm
Location: Somewhere over the rainbow..

Re: Hobbs meter

#2 Post by jph »

Are you asking about a 'bodner card' or about Air Manager ? - where does AM come into this ?
“Everything in moderation, including moderation.”
“Experience is merely the name men gave to their mistakes.”
Joe (CISSP) -IT security consultant

stephane130281
Posts: 11
Joined: Sun Aug 07, 2022 9:54 pm

Re: Hobbs meter

#3 Post by stephane130281 »

It s about the leobodnar card. But it is in the cockpit building section so I was seeking some help from here but apparently I was wrong.
Nevermind my question, I ll delete this post.

PS: not sure I can delete it. To the admin, please feel free to delete this post. Thanks.

Regards
Stephane

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jph
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Joined: Fri Apr 10, 2020 12:50 pm
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Re: Hobbs meter

#4 Post by jph »

I was asking as you may have AM being used in hardware so could have ignored the bodner thing.
The bodner board is a simple pic micro and will not tolerate 12v anywhere.

To drive the 12V hobbs you could use an output from the bodner board to drive a 2803 or a prebuilt opto isolated relay module only a euro or so, or a simple npn bjt with a base resistor and flyback diode, or a mosfet... loads of ways

you can do exactly the same in AM but with far far cheaper hardware.
“Everything in moderation, including moderation.”
“Experience is merely the name men gave to their mistakes.”
Joe (CISSP) -IT security consultant

stephane130281
Posts: 11
Joined: Sun Aug 07, 2022 9:54 pm

Re: Hobbs meter

#5 Post by stephane130281 »

Thanks a lot for your reply. I ll check that out. Definitely won t connect the 12V ouput to the Leobodnar card.

Have a pleasant day.
Cheers

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jph
Posts: 2030
Joined: Fri Apr 10, 2020 12:50 pm
Location: Somewhere over the rainbow..

Re: Hobbs meter

#6 Post by jph »

no worries,

you could use one of these, just connect an output from the bodner to the input pin on one of the seven channels and the 12v goes to the hobbs, then the 'gnd' lead from the hobs goes to the other side of that channel on the ULN 2003

the 2003 is just a 7 channel version of the ULN2803A

it will work perfectly.

https://pt.aliexpress.com/item/40011005 ... 71wgCl7aQR

And you have another 6 channels to use. The jumper on pin 9 can be removed unless you use a relay. You can use different input voltages on the load side for each pin, anything from 5 to 50V and up to 500mA current.
Very versatile.

No other components needed.

If you have an old BY28 type stepper driver you can also use that as it also uses a ULN2003 Darlington driver array.
“Everything in moderation, including moderation.”
“Experience is merely the name men gave to their mistakes.”
Joe (CISSP) -IT security consultant

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