Polaroid Joshua Vision Service Manual page 38

As you would expect, this switch powers the camera circuits after the VER to Gnd contact is opened and
the VER to B+ contact is closed. The VER and B+ wires are variously actuated by the door latch, lower
erect link or the film shade lug, depending on whether the camera is folded or erected.
For clarity, therefore, only the parts which are operative in a given situation will be shown in each of the
following explanations.
Powering a Folded Camera when a Filmpack is Inserted
Since film may be loaded when the camera is folded, and because darkslide should occur immediately,
darkslide power is needed in a normally unpowered camera. In the Joshua, this requirement is met by the
action of a Film Shade lug on the Dark Slide Link, a pivoted finger on the Power Actuator.
When the film door is opened, the spring-loaded Dark Slide Link rotates to a downward-pointing position,
becoming a rigid extension of the Power Actuator (Figure 2-4).
Figure 2-4. Film Door Open
When the film pack is inserted and the door closed, a lug on the Film Shade forces the Dark Slide Link/
Power Actuator assembly upward, raising VER and breaking the VER - GND contact (Figure 2-5).
Figure 2-5. Film Door Closed
2 - 6