Hi,
I am hoping to modify an audio mixing desk so that when a latching
pushbutton switch is depressed, a miniature LED will illuminate to
indicate activation (as it is currently very difficult to see with
black (non indicating) pushbuttons on a black background used in dim
lighting conditions !!).
The problem I have is that the switches are DPDT latching, and BOTH
poles are currently used to route audio signals. I presume that it is
not possible to connect an LED to one of these poles as it will
introduce voltage / current where the original design wasn't expecting
it....
I had thought about miniature DPDT relays... re-route one 'pole' of
the audio signal off the existing switch onto one pole of the relay,
use the freed-up pole on the existing switch to drive the relay and
use the spare pole on the relay to switch the LED. However, with
thirty switches to deal with, this could be expensive and cause quite
a power drain.
Is there any easier way (transistor ?) to switch an LED when you only
have a DPDT switch (with both poles used for other things !) ??
Many thanks for any help you can give.
Cheers,
Kev.
I am hoping to modify an audio mixing desk so that when a latching
pushbutton switch is depressed, a miniature LED will illuminate to
indicate activation (as it is currently very difficult to see with
black (non indicating) pushbuttons on a black background used in dim
lighting conditions !!).
The problem I have is that the switches are DPDT latching, and BOTH
poles are currently used to route audio signals. I presume that it is
not possible to connect an LED to one of these poles as it will
introduce voltage / current where the original design wasn't expecting
it....
I had thought about miniature DPDT relays... re-route one 'pole' of
the audio signal off the existing switch onto one pole of the relay,
use the freed-up pole on the existing switch to drive the relay and
use the spare pole on the relay to switch the LED. However, with
thirty switches to deal with, this could be expensive and cause quite
a power drain.
Is there any easier way (transistor ?) to switch an LED when you only
have a DPDT switch (with both poles used for other things !) ??
Many thanks for any help you can give.
Cheers,
Kev.