Polaroid SX70 manual S4 Switch operating configurations

Figure 2-8 S4 Switch operating configurations

damage to the circuit in the event that flashbulb becomes short-circuited after it is fired.

e- Switch S5 (normally closed at the beginning of the exposure cycle), like S3, is located in the gear train and actuated by the recock ram (Figure 2-7). When the gear train rotates to appropriate point in its cycle, S5 opens and removes power from the drive motor, applying dynamic braking voltage to stop the gear train quickly. The ECM reacts to this command in such a way that exposure cycle continues completion even through the operator has released the exposure button (S1). After the exposure and when the Fresnel carrier returns to the viewing position, S5 is closed by the recock ram and stops the camera cycle.

f- Switch S6 is closed by openong the camera to the picture taking position. Its disconnects the negative side of the battery from the commun return (ground) when the camera is folded to assure the removal of power from the circuit.

g- Switch S7 is closed when the front cover is closed. It is wired in series with S6. Like S6, S7 disconnects the negative side of the battery from the commun return so that the camera cannot function until the front cover is closed and latched. It is an interlock during normal picture taking. With S6 and S8 closed, it initiates the dark slide function.