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> Paul, have you ever tried to reset a 50, 70, or 100-amp circuit breaker
> in flight? In the few cases I have seen when such breakers have tripped,
> the crews were unable to reset them. We reset them on the ground, using
> a soft mallet.
>
> I remember one airframe manufacture putting the alternator output
> circuit breaker in the floor beneath the pilot's feet. That allowed the
> pilot to stamp his foot on it to reset it.
>
> How much experience do you have with aircraft electrical systems, Paul?
I've a switchable 50A CB on my gear hydraulic pump; 'hasn't needed
a mallet yet to turn it off or on. As for experience, I have designed
solid-state voltage regulators with series OV protection, buck-boost
regulators for permanent-magnet alternators to keep the charge going
when the alternator voltage output is less than the battery voltage, CD
ignition systems, electronic fuel injection systems, augmenter exhaust,
propellers, rocket engine igniters, O-200 external engine starter, VHF
and UHF antennas. Lots of previous experience designing computer mods,
a total radar simulator, L, P,and X-band receivers and transmitters,
X-band antennas, antenna simulator equations, phase-lock loops, motor
controllers, ATLAS autopilot simulator equations, radio and light
refraction equations for ATLAS guidance, radar-tracking tropospheric
noise model. So I've a little electronics knowledge and experience.
I've a friend who took off with a low battery that required him to
get a hand-prop. 'Seems that on the short 10 mile return to his home
airport, his alternator breaker popped and wouldn't reset. During his
short taxi at low rpm, the alternator didn't put out sufficient current
to pop the breaker, but during takeoff and climb it did, well in excess
of the breaker rating because of the discharged state of the battery.
Again I will say it; if you do not think what I have written can happen,
then just ignore it! BTW, have you ever put an O'scope across a
battery's terminals to see what it does with narrow, high-voltage
transients? I've!
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Re: Frying your avionics
