737 Trim Air Valve

[Sean]

I got one of these little 1" gauges (the ones that Maurice hates so much) and was playing around with it.

It has 4 terminals, L1, L2, + and -

5v across L1 & L2 lights it up and 1.5v (from a AAA battery) sends the pointer full deflection from left to right.

From the FCOM:

Outflow Valve Position Indicator

• indicates position of outflow valve
• operates in all modes

Questions:

1. Is needle full left valve closed and needle full right valve fully open?

2. What voltage range would I use? 1.5v seems too much.

3. Is this system modelled in any of the current system software suites?

Sean

[TomR]

Hi,

1. Is needle full left valve closed and needle full right valve fully open?

Fully left closed, fully right open.

2. What voltage range would I use? 1.5v seems too much.

It operates with 0.2V ish for full deflection. Best is to use a resistor 12 kOhm to 15 KOhm (12,000 Ohm to 15,000 Ohm) in line. That gives you higher volt range to operate, depending on the resistor 3.5V ish.

3. Is this system modelled in any of the current system software suites?

We do, but TSR-Systems B737 is not for public.
PM doesn't as far as I know, may be Sim-A or Prosim does.

[Sean]

Thanks Thomas, I appreciate your input.

[Sean]

Excuse my ignorance, but what is TSR-Systems B737?

[mickc]

Prosim fully models this gauge, and the whole pressurization system.