Rollei 35 T light meter current flow

I was drawing a circuit schematic for the Rollei 35 T and I didn’t see right away how battery positive gets to the photocell circuitry.

I learned it’s grounded to the camera’s metal frame when the battery cap tightened down by the user.

I noticed the presumably + pos red wire connects one of the variable resistors to the meter. That suggests the red wire is directly connected to the camera frame somewhere inside the meter housing. An ohm meter check confirms this.

I opened it up to see how it’s done. I know galvanometers only need two wires so I wondered why there were three electrical paths leading to the meter.

I think it’s because Rollei got the meters, with both wires, from their supplier Gossen in the raw state as seen in this video Then Rollei assemblers drops them into the black housing and make the two connections to the variable resistors. The third connection was made when the orange cover was installed. It saved a production step.

By the way, the meter cover has two moving parts... the indicator needle with the circle and slide that is spring loaded against a camera body lever whose position is determined by shutter speed, ISO and lens f setting. The cover and its parts have no connection with the inner meter workings. Its parts will stay in place and not loose calibration if you remove the cover.