Film-Tech Forum ARCHIVE: Ernemann 15: How are the focus, framing etc... switches connected to the motors?

This is topic Ernemann 15: How are the focus, framing etc... switches connected to the motors? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=005984

Posted by Adrian Steiner (Member # 1527) on 03-22-2004, 04:32 PM:

Is anyone of you familiar with the control boards of the Ernemann 15 projector?
Especially how the switches for framing, focus, lens turret and aperture plate are connected to the motors?
We're on to build a remote control for it. Our idea was to use relays in parallel to the switches on the control panel of the projector.

Problem:
The switches for framing and focus seem to be on-off-on types, the ones for the format change (on)-off-(on). (on) means an
impulse contact when switching.
Do they directly switch (a) the motor current or (b) an input signal for some logic circuit?
If (a), then there could be a problem when someone at the local switches would put the switch on one side,
while on the remote one someone would put it on the other side. -> shorten circuit.
In case of (b) there will probably be some kind of priority when the local and remote switches are moved to
opposing positions.

Thanks for any help!

Adi