# 1975 General Electric RPM Avionics instrument Tach

Hi, I would lilke to learn from scratch how to design or make a circuit that will control my GE Avionics guage that 's in the link below ,like this:::

I need it to run on RS-232 or USB which ever is easier …if possible!!!

It needs output voltage = 115VAC **
** output Freq = 400Hz for input or out put

** Output current 0.26A continuous**
----------------------------------------------------------------------------------------- **
** Input Voltage= 28VDC (nominal) 24 to 32VDC; 18VDC to 36.4VDC (abnormal range) **
** Input Current= 1.35 AMPS typical @ 28VDC input

it needs this to work unmodified as its original and I dont want to dismantle>
https://www.bing.com/images/search?view=detailV2&id=2E98B0992EDCFF8BE59B376E95475A772F1A973F&thid=OIP.uro4xXgambMNCbpcmptVVQAAAA&mediaurl=https%3A%2F%2Fi.ebayimg.com%2Fimages%2Fg%2FkPcAAOSwmWVau4Vq%2Fs-l300.jpg&exph=200&expw=300&q=king+air++RPM+tacho+avionics+guage&selectedindex=5&ajaxhist=0&vt=0&eim=1,6

Hi,

Sounds like you’re just kicking off with a journey into electronics. The short answer is, this is going to be a fairly decent time-commitment project.

First of all, 115VAC is lethal. Only a qualified electrician or technician should be working with those voltages. Especially in Australia, where it’s a criminal offense to do so, and will void house insurance etc if a fire or damage ensues.

But I’d be surprised if you even need to use that gauge. You could 3D model something similar, use a couple of small servos and make something that “looks” like this but is entirely DIY.

The best place to start is to learn the ropes with electronics. To do that, consider a kit like this:

That kit will take you through all of the essential steps to build circuits, and program a development board (in this case, an Arduino board). Included is a guide for working with servos, which could drive the dials on the DIY gauge.

Then, get into 3D modeling guides. You don’t need a printer if you prepare the file and send to a printing service.

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I want to build my IO card or cards with custom pics that will do everything like the Arduino because it is costly if i need more then one?

Sure, the option is up to you!

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I need some help from the knowledgeable people here to help me understand how to build IO cards . Im newbie .

Now i will do my homework as well ,it is clearer when somebody explanes in detail everything .If you know what I mean I have Alot of Electronics books and they dont explain anything from beginning ,they expect a Electronics Degree or something.

it’s like the knowledge you get from Tafe is not the same as in University.

Hi Schematicsman,

I’ll be honest, I had to google what an IO card was. I think you are trying to start out at an Electrical Engineer level. I recommend trying out Arduino, as its very well documented and designed for all levels. Later down the road when you have a better understanding you can move into designing your own boards. You shouldn’t really need to though because available boards are so versatile.

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It makes me upset when people explain in books dont explain everything so the interested reader understands to the point where he can go of and build anything he thinks of you know>…

If it were easy, everyone would be creating innovative products that change the world!

You’re going to have to get your paws dirty, you may even make mistakes along the way. Though the kit I shared is a solid starting point and very well reviewed.

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thank you all:)

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