On Thursday, February 20, 2014 5:48:21 AM UTC-5, wrote:
Hi,



I have a V7 vario connected to an Oz FLARM and HX4700 PDA. All devices get powered from V7.



If the PDA is not 100% charged, the V7 resets in flight. When it happens, FLARM restarts and the program that runs on the PDA looses GPS signal.



Usually the program comes back as soon the FLARM regains the PS signal, but every now and then, the programs drops to he operating system and the flight stats are lost.



Has anyone experienced this problem? Any advice or suggestion will be appreciated.



Thanks

Jarek

LX V7 manual, p33 of 39, says 5v output is 1 amp max.
Ozflarm manual says it draws 55 ma (typical), double that when alarming, so 110ma.
ipaq 4700: according to Daryl Ramm's power budget briefing to PASCO (google it), IPAQ 4700 draws .39A charged (page 22), .99A flat (page 25), assuming full backlight (I had a 4700 and this was the only way I could see it). I assume you have any unnecessary programs, wireless and IR shut off on your 4700 to save power...

It looks to me like you're just drawing too much power, and it is overheating and shutting down. It might be just under max until the flarm warns, and then shuts down when you need it most.

My last PDA 3955 drew easily over 1A (tested with ammeter) when it wasn't fully charged. I used a PWR-5B Power Converter for mine, and it was quite efficient and trustworthy.

At the cost of a V7 and the likelihood of damaging it, I'd get another 5v power source for one of the two systems you currently have connected.