Hi all,
This may be a slightly long post, but I'll try and get all the relevant info out of the way before posting
OK, I'm just bought a pair of pitot ammeters off eBay. The seller claimed they came out of a 707, btu couldn't offer any further info. Now they've arrived, I can see all the bits that weren't in the pictures, including the very solid-looking connector on the back. This connector has 5 pins arranged in pentagonal form, with 3 locking studs protruding from the surround. Two of the pins are numbered 1 and 5, obviously indicating the convention. The front of the meter is marked 'PITOT AMPS' and graduated from 0 to 3 (centre of the dial) in half-amp increments, then to the other end of the dial (up to 10) in smaller increments. The side of one of the meters has white-printed text reading:
'PITOT AMMETER
WACLINE, INC. DAYTON, O.
WACLINE P-N LKCC-18024
WACLINE SERIAL NO. 225'
There are also some other printed marks, none of which are very readable except for one reading 'July 68'.
My question is this: what's the pinout for the connector at the back? I already know the following:
pin1 - connected to pin2, and meter chassis
pin2 - connected to pin1, and meter chassis
pin3 - connected to pin4
pin4 - connected to pin3
pin5 - ?
My guess was that pins 1 and 2 are supposed to be the aircraft's 0V, with pin5 the positive supply, but hooking it up to 12Vdc did nothing, so I'm leaving that well alone for the moment. Applying a voltage across pins 3 and 4 made the meter register a current however (3A...all I could bear to give it before my [thin] wiring melted).
Any help would be much appreciated - I'm positive there's some way to make then light up (everything in the cockpit does, right?
) which would be cool beyond belief
I'm also slightly concerned by an amateur-pilot friend mentioning that they aren't supposed to be used as inline ammeters...so what *are* they for, and how can I make them do it?
Many thanks.