THE UNISELECTOR
The Uniselector has a rotating centre wheel with arms extending from it (called wipers).  An electro-magnet pulls the armature (top left) downwards.  The pawl (centre), which is held against the ratchet wheel operates the ratchet when the armature restores.  As the wipers are fixed to the ratchet wheel they therefore rotate one step.

The wipers are in contact with the contact bank shown to the right of the picture.

When the call clears - the wipers are driven to the home position.

 
 
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Last revised: January 28, 2023

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