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I have a circuit that needs to electrically output a pressure value and display it using analog dial gauge. First I wanted to use regular round ammeters but they don't look like "real" pressure gaugeish. Have a look to get an idea about what I mean

Ammeter Pressure gauge

Needle in a pressure gauges is usually mounted in the center and have a much more wider travel sector. The best I can think of is to get an auto tachometer, print a new dial face with pressure scale and remove all unnecessary control electronics from the tachometer leaving only galvanometer and a precision resistor inside. Then I plan to drive it with PWM. There is another type of tacho that uses a small stepper inside. This should be also fairly simple to drive.

enter image description here

I don't want to reinvent the wheel, so want to ask if anybody knows about a product that does exactly same job, i.e. pressure gauge simulator?

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If you haven't already decided on which pressure transducer you want to use, chances are you can find a manufacturer who can fix you up with something sporting a pressure range and a remote readout that suits you.

If not, there are lots of nice analog panel meters around with dial faces you could modify and with their pointers rotating about the center of their dial faces like you want, like the one below,say, and a few more here enter image description here

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  • \$\begingroup\$ Actually I will output pressure value from a software running on a computer. But those gauges would do the job. Thanks! \$\endgroup\$ – Farid83 Sep 30 '14 at 19:21
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While there are fairly wide angle moving coil meters, to get to 270 degrees you probably need either a stepping motor type (with some provision for homing the pointer since steppers are increment not absolute positioning devices) or an air core movement. The latter have to be driven in quadrature (2 coils driven with currents x and y representing sin and cos), the the resulting pointer angle \$\theta =tan^{-1}(x/y)\$.

One of those two types is likely what you'll find in modern automotive gauges. ASICs are available to drive each type or you could do it in a microcontroller with suitable drivers.

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  • \$\begingroup\$ Stepping type seems to be easier to drive at first glance. I guess I will just buy one of those old style car tachos and gut electronics out. \$\endgroup\$ – Farid83 Sep 30 '14 at 19:24

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