ideas on interfacing real 737 start switches ?

[dnoize]

Hi,

I was wondering how others solved interfacing their real 737 start switches.

Releasing the solenoid shouldnt be a problem, but i wonder how others solved the weird combinations of the cont and flt positions.

grd position also trigger the cont and flt terminals. Anyone who thought of a workaround for that ?

Stef

[nricky]

Hi Stef

You are one of the Lucky once that got 2 Real 737 Switches. Your best bet is to try it with Opencocklpits. The olso have a Relay Card for holding the solenoid in position and the rest are just switches you have to program ti use PMSYSTEM.

Will be at the show in Lelysted maybe you can show me the switches, that woudl be great.

Cheers Norbert

PS still working on the 737

[dnoize]

Hi Stef

You are one of the Lucky once that got 2 Real 737 Switches. Your best bet is to try it with Opencocklpits. The olso have a Relay Card for holding the solenoid in position and the rest are just switches you have to program ti use PMSYSTEM.

yup, and spares too ;-)


Will be at the show in Lelysted maybe you can show me the switches, that woudl be great.

no problem. hopefully they will be working in my overhead that i will have on display, but i will bring the spare too, so you can see it.



PS still working on the 737

it never ends :-)

Stef

[Simzation]

Stef,

I interfaced the start switches with Phidgets and it worked like a charm.

There are four positions on the start switch and I used three of them.

No1. for GRD
No2. for CONT
No4. for FLT

No3. position is probably for backup or something like that. if you take off the aluminum casing you can see how and when the microswitches inside are activated when selecting GRD/CONT/FLT.

Please let me know if this solution works for you as well.

Kind regards,

Boy Bruin

[dnoize]

hello Boy.

As you know the startswitch is basically 4 microswitches, switched by a internal cam rod inside the switch.

when you put the switch into the GRD position, this cam rod also switches the microswitch for the FLT and CONT position.

I was worried this might confuse pmsystems. But everybody that replied to me wires it that way. so obviously it works like a charm within pmsystems.

I think i will go for the phidgets route too....

Thanks for your reply.....see you in november :-)

btw. no. 3 is for LOW IGN as used on older 737's

Stef

[Michael Carter]

True on both the 737-200 and some models of 727.

The low energy continuous ignition would fire the igniter in can 4 of the combustion chamber. In the high energy continuous ignition it fired both igniters in the #4 can and the #7 can alternately.