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A wisp of smoke.....

dave4754

Well Known Member
Ok I was bored one night and thought I would check out my new to me Turn and Bank indicator electric 14 V.

A little tired i misread the pinout and connected postive to negative and it didnt power up of course.

The little wisp of smoke arose in the glass and my question to any who might know is:

is it toast? Have i just wasted 500 dollars worth of T/B instrument?

The unit is

Electric Gyro corp. Model 13494T100-(54)

Would you pay to have this model rebuilt?

I hate being this stupid but it helps to remind me I am human I guess .LOL
 
Usually, if you let the magic smoke out, the thing won't work any more. Easy enough to check, though; just hook it up properly & see if it works.

As to whether to have it rebuilt, have you looked at what solid state units are selling for these days?
 
Solid State?

No I havent i really am out of my league on these things.

What brand would you suggest that is solid state and reasonable cost. I have Dynon on board and this is going to be backup during night VFR.
 
I'm a bit surprised the magic smoke came out. I thought those units only had a gyro in them with no solid state electronics and expected it simply to run backwards if the power inputs are reversed. :)

Does anyone know what circuitry is inside the unit?

I STAND CORRECTED...

Apparently there is probably a circuit board in the back of the unit with fried components.

https://www.youtube.com/watch?v=WbaRm12nRL4

If you want a DIY repair look at the large electrolytic capacitor for replacement. The escaping smoke was not a good sign.
 
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If it had an LED backlight you might have exceeded the reverse voltage and let the smoke out of the little LED in the unit. That should be replaceable.

Ah - its an older unit - Gil's probably right and you smoked a cap or a diode on the board. Again, probably repairable.
 
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No I havent i really am out of my league on these things.

What brand would you suggest that is solid state and reasonable cost. I have Dynon on board and this is going to be backup during night VFR.

If you really want a T&B instrument, I'd suggest looking at the solid State device (available as a TC or T&B) from BeLite. Small, weighs almost nothing, bright display, no moving parts, and fits in a 2 - 1/4" hole. And for what it will cost to send your unit to a shop, you can pay for the BeLite. I've had one on the glare shield of my -8 for a few months, and it just works.
 
Closing off Thread - final remarks on T/B

The T/B unit proved to be older than i thought and although picked up by a reputable manufacturer many components had changed making this one ancient.

The reverse polarity caused a meltdown of the Capacitator and resistor in the circuitry in back of the gyro.

My local avionics shop in Edmonton were great guys and gave me a core trade in on an RC Allen overhauled unit at 850 Cndn which is pretty good considering they are 12 to 1300 New.

This device in my mind is critical when at night and the Dynon goes offline on you in the dark. Of Course i could borrow my wifes necklace and hand it from the crossbar but I would have to have access to Youtube to make that work! lol

Thanks as always for any info passed on this... on to some more rivet banging... at least they dont smoke~
 
Most of these electric gyros have a voltage regulator and no diode protection for reverse polarity. (The cost of a few pennies). I've repaired a few over the years with a smoked regulator. If you can find someone electronically inclined perhaps he could replace it for you. There would be no other damage besides the voltage regulator.
 
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