Here's what the underside looks like. Still a puzzle to me.
Attachment 211692
Printable View
Here's what the underside looks like. Still a puzzle to me.
Attachment 211692
That could be. But why all the sensors around the lens opening? One would be enough to signal the end of exposure.
i still dont see the sensors but i do see diode symbols at each of the 9 contact points in that spaghetti etching so each is polarized. each of the 9 contacts also has 2 connections. 9 photo diodes looking down at the easel?
ok so hook up a vom n trace them out using light and see if you get any resistance change?
interesting! gotta be from some sort of an automatic system.
EE son tells me the symbols might indicate direction of current flow, rather than an actual diode. Since this is likely for DC, might make sense. This was mounted around the lens opening in the lens turret, facing up toward the light source. So it must be measuring some characteristic of the light.
yes that would be directional current flow and the diode electronic symbol would be indicative some sort of diode there.
i dont see any sensors looking up, i only see 2 solder connections at each symbol. the sensors are more likely facing down at the easel .
interesting gizmo for an enlarger.
i hope someone can ID it?
This was mounted on the upper side of the lensboard. The sensors (if they are sensors) are facing up - toward the light source - not down toward the easel. This photo is with the lens turret removed, looking down through the lens in the same direction as the light from the head.
Attachment 211804
I have heard mentions (I think in Ansel Adam's The Print) of light sensors being used as feedback to keep the light intensity of a cold head constant. If those diode symbols indicated photodiodes, this device could be for that purpose.
and some high voltage cold lamps were stabilized by thermistor and heaters
sometimes very complicated circuits