tmo wrote:
Granted that is a potential issue only on 28V systems
Why only on 28V systems?
Airborne_Again wrote:
Why only on 28V systems?
Because crappy voltage regulators from 1930’s tractors some of us have on certified airplanes sometimes fail to provide power clean enough for modern electronics to run off of.
See the “specs and data” section of https://www.surefly.aero/copy-of-home
SureFly wrote:
* A note on input voltage:
Installers have reported that a small number of 24V aircraft have noisy electrical systems that generate momentary voltages beyond 30 VDC. The SureFly SIM is engineered, approved and tested to perform between 8.5 VDC and 30 VDC. And actually, in practice, each SureFly SIM is proven and tested to perform between 5.5 VDC and 35.7 VDC. But with a small number of 24V aircraft, since the SureFly protection circuit is so much fast faster than some aircraft voltage regulators (normally limted to 32 VDC max), momentary aircraft electrical system inputs more than 35.7 VDC to the SIM will trigger the SIM’s over-voltage protection circuit in order to protect the internal components from the high voltage. The operator may perceive this as engine “stumbling” in certain phases of ground or flight operation.
Aircraft electrical noise may be caused by any number of factors unique to each aircraft and/or phase of operation. To prevent this condition for any (and all) airframes, SureFly has developed and received approval for a power conditioner. The PC17V is a power conditioning module that is installed between the aircraft electrical system and the SureFly. The PC17V consistently provides 17 VDC to the SureFly SIM. Combined with a capacitor, this setup provides stable power to the SIM even in the worst cases making the SureFly SIM even more robust and compatible with all applicable airframes regardless of the cause of the aircraft’s electrical noise. Speak to a SureFly technician to better understand if your particular 24V aircraft may perform best with the SureFly PC17V.
tmo wrote:
Because crappy voltage regulators from 1930’s tractors some of us have on certified airplanes sometimes fail to provide power clean enough for modern electronics to run off of.
The quote from SureFly made the issue clear. Thank you.
So this isn’t an issue with 12V systems because momentary overvoltages would still be below the 35.7V maximum for the SureFly.
Does anyone know what are the failures like in e-mags? there are no moving parts but I tend to think it might fail instantly because of an electronic failure without any warning signs vs traditional mags more likely to start talking to you before complete failure. What do you guys think?
Because crappy voltage regulators from 1930’s tractors some of us have on certified airplanes sometimes fail to provide power clean enough for modern electronics to run off of.
According to my hangar elf, spending five crisp 100 dollar bills on a Zeftronics regulator is a very elegant fix for those with voltage sensitive avionics.
Electronic ignition posts moved here.
The Lamar regulators, which have been around for decades, are as good as you will get by modulating the field current.
T28 wrote:
According to my hangar elf, spending five crisp 100 dollar bills on a Zeftronics regulator is a very elegant fix for those with voltage sensitive avionics.
A smart elf you have there; I read good things about Zeftronics too. Agree that is the better approach than a power conditioner for just the SureFly.
What can a regulator do that is special? It merely modulates the field current of the alternator.
What effect does the field current modulation have on alternator output and bus voltage?
By9468840 wrote:
Does anyone know what are the failures like in e-mags? there are no moving parts but I tend to think it might fail instantly because of an electronic failure without any warning signs vs traditional mags more likely to start talking to you before complete failure. What do you guys think?
Have a look at vansairforce.net for problem threads where the PMags/EMags have been discussed since their introduction. From what I gleaned, they don’t like to be in a too hot spot, i.e. a cooling duct from the baffles seems a standard installation feature; otherwise the magneto check and respective switching gear are a bit more than a standard key switch because you want to test the grounding path to disable spark independent from the disconnect from the ship power (testing the self-sustaining generator).
