Whats this for a knob / switch ?

[markusr]

Hello guys,

I recently have ordered from a private person one B737 Audiopanel for my pedestal.
I saw that the switches / knobs have also a lamp included. I tried to find any specs or datasheet of this "thing" in the internet. No luck until now. There is also no type printed on the switch or it is unreadable...
Maybe you have seen such a part and can give me some information. Is there a trick to open it to see what lamp / led is built in, so I know how many V I can connect. The basic "push" function I have already found and so I can connect this switch to a yostick card to get the function in FSUIPC. My goal is, when it is pushed that the lamp will light on.

Here is a link to the pictures of the parts.

https://picasaweb.google.com/compuma...eat=directlink

Thanks and best regards,
Markus

[fordgt40]

Markus

The internal lamp runs off a 5 volt supply. Sorry, I have no further info as my 737 audio panel was bought complete with 14 of these - I do not want to take them apart

David

[markusr]

Hello David.
Thanks for the info, can you tell me also which pins need to be connected for the lamp - or are they already built in completely?
Markus

[Geremy Britton]

This may help:

http://www.mycockpit.org/forums/show...o-Panel-Wiring

[dnoize]

this is a really old one.

The newer ones are manufactured by electro mech: http://www.electromechcomp.com/

the knob itself does not have a light in it.
It is edge lit.
The lighting is in the panel.
When you push in the knob, the lighting of the panel strikes the lower transparent ring that you see at the lower end of the knob. This reflects the light and lights up the top of the button when its pushed in.

You have 2 4 pin terminals, one on each side. all pins are for the 2 (most likely green) internal microswitches.

at the bottom of the assembly you have the pot with a number of terminals.

no pins for the lighting.

Stef

[fordgt40]

Stef

Thanks for that info - it explains a lot. It never occured to me that there was no electrical answer to the light coming on when the switch was activated.

David

[markusr]

this is a really old one.

The newer ones are manufactured by electro mech: http://www.electromechcomp.com/

the knob itself does not have a light in it.
It is edge lit.
The lighting is in the panel.
When you push in the knob, the lighting of the panel strikes the lower transparent ring that you see at the lower end of the knob. This reflects the light and lights up the top of the button when its pushed in.

You have 2 4 pin terminals, one on each side. all pins are for the 2 (most likely green) internal microswitches.

at the bottom of the assembly you have the pot with a number of terminals.

no pins for the lighting.

Stef

Hello Stef,

if I get this right I need to connect +5V toto 2 pins on one side with the 4 pins. When the button is pushed the switch is triggered and the curcuit is closed so the lamp will light up. As picture 2 shows a resistor is attached between the first and second pin of the row of 4 pins. I will upload a better picture in the evening.


With

The lighting is in the panel.

you mean that the light is behind the cover trom the switch?

Thanks for your help.
Markus

[fordgt40]

Markus

What Stef is saying is that there is no lamp in the switch. The light that is seen in the knob is "borrowed" light from the panel backlighting. This explains why I could not find a "circuit" to turn on my "lights" - yet they worked when the knob was moved.

David

[markusr]

Ah, ok. I think i got it now.
When I have no backlight also the buttons won't light up.
The only thing that does not align to this idea, why is there an resistor mounted directly on the switch between pin1 and 2... And when you look straight down to the switch you can see a siluette of an light.
I will take Makro shots today. It's hard to explain...

Markus

[fordgt40]

Markus

The resistor is there for the other control electronics when changing channels and volume levels - at least it is on my panel. The switch "light" comes on when selected and when power is only fed to the backlighting, nothing else. Your switch may be different, however, I doubt it

David