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If the camera is now folded, the reverse happens: VER opens from B+ and is then shorted to GND. This

discharges a capacitor in the Power Supply, so that when the Camera is later erected, the microprocessor

knows the strobe should be topped off.

As mentioned above, it is the Door Latch, not the Door, that affects the B+ wire of the Power Switch. The

reason is to prevent application of power and motor start when the Door is almost but not fully closed. The

camera could attempt to darkslide and to rotate the drive gears in the Mainframe before they were smoothly

and fully meshed with the gears in the Door. Thus closing the Door has no effect on the power circuit, but

latching the Door does.

Conversely, using the Door Latch in the power circuit rather than the Door also means that power is cut off

before the Door is opened and the gear mesh is broken. When the Door is unlatched, the Door Latch cam

allows the Door Latch Sensor to pivot upward (CW), driving the B+ wire upward and out of contact with

VER.

Maintaining Power for Processing after Camera is Folded

Folding the camera from an erect position would normally cause the Erect Link and Erect Sensor to shut off

the power, as just described. But folding the camera while a processing cycle is taking place (after the

mirror is down) must not be allowed to interrupt the power. If it did, the motor would stop in mid-cycle,

ruining the picture.

How does the camera maintain power long enough to complete the processing cycle, after it has been

folded? Figures 2-10 and 2-11 show how the novel Power Actuator Assembly, in conjunction with the

movement of the Film Shade, performs this critical power-maintaining function.

In Figure 2-10, at the start of the film processing cycle, the camera is erect and power is on because the

Erect Sensor is holding VER in contact with B+. If the camera is now folded, wireform VER would

normally drop down, opening B+ to VER and killing power.

Figure 2-10. Power On at Start of Processing (Camera Erect)

Polaroid Joshua Vision User Manual

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