Strobes & What Can Go Wrong........

[Brian]

Had an engine out today, 23 minutes into the flight and

[Briglow.Joe]

Brian, Good to hear it ended well in the end.

[chook]

Chopper - good outcome.Ok strobes. In another previous life I repaired automotive tuning aids as a sideline. The old electronic timing light is simply a strobe which is initiated from the spark going to the spark plug (on cylinder #1) They work by using a transistor to switch a step up transformer which produces anywhere between 300 - 450 VDC across a xenon gas filled discharge tube. The aviation models then use a small timing circuit to activate the discharge instead of using the spark pulse. Because of the reasonably high DC working voltages these things are very susceptible to dust, moisture and heat failure. Chopper in your situation the failure of the strobe was probably due to the failure of the trigger cct somewhere. This would have allowed the charge voltage to rise to the higher level and stay there putting a lot of stress on the components and causing the switching transistor to short circuit and in turn causing your fuse to fail (another good reason to have cct breakers in critical power ccts like ignition - if you had altitude you may have been able to isolate the faulty feed and attempt a restart)Matt your concerns over the feedback pulses are valid. I deal with a lot of aviation radios here in WA and some of the power feed noise is generated by these strobes. Importantly the engine manufacturers have some heavy duty filters in the front ends of their ECU"s which generally save the day.What have I got on my gyro - I have used shielded microphone cable (good size conductors) to the strobe and run the shield back to a central star earth point. Result - no radiated clicks or high frequency whine while she is running. The best test for any noise in your power system is to listen to your radio with the squelch turned off so that you can hear all of the normal airband background noise (use a vacant channel). Then start switching things on - like fuel pump, strobes other radios etc and listen. The acid test is to then switch your radio off without changing any settings and start the engine. Now turn the radio back on and see how much noise has been introduced.

[Briglow.Joe]

Thanks Chook,I guess my question was, When we chop these engines out of a car and simplify the wiring circuits to the ECU are we not replacing all the filtering mechanisms that it or originally had.But as you say if the filtering mechanisms are attached to ECU then they should still be present and operational once install in a gyro.RegardsMatt

[mad max]

It"s a good idea to have all the non-critical gadgets on a separate low as possible amperage fuse Brian. I even have my carb. solenoid on a separate 5 amp fuse so if it shorts the ign. keeps going. I pass my tacho. pick-up through a 24v-3w globe so if

[tonydenton]

good that your good brian. did you retrieve or get off again. how did that go?

[Brian]

good that your good brian. did you retrieve or get off again. how did that go?

[birdy]

[i]Had an engine out today, 23 minutes into the flight and

[Brian]

[i]Had an engine out today, 23 minutes into the flight and