Precision pressure generator system

Claim 1

A PRECISION PRESSURE GENERATOR SYSTEM FOR GENERATING A PNEUMATIC OUTPUT PRESSURE IN RESPONSE TO AN ELECTRICAL INPUT SIGNAL COMPRISING FIRST MEANS FOR GENERATING AN ELECTRICAL INPUT SIGNAL, SECOND MEANS RESPONSIVE TO SAID OUTPUT PRESSURE FOR GENERATING AN ELECTRICAL SIGNAL CORRESPONDING TO THE OUTPUT PRESSURE OF SAID SYSTEM, THIRD MEANS RESPONSIVELY CONNECTED TO SAID FIRST AND SECOND MEANS FOR DERIVING THE DIFFERENCE BETWEEN SAID ELECTRICAL INPUT SIGNAL AND SAID SIGNAL CORRESPONDING TO THE OUTPUT PRESSURE OF SAID SYSTEM, A COURSE CONTROL PRESSURE CHANNEL, A FINE CONTROL PRESSURE CHANNEL, SAID FINE CONTROL PRESSURE CHANNEL BEING CONNECTED TO RECEIVE THE OUTPUT OF SAID DIFFERENCE DERIVING MEANS, SWITCH MEANS RESPONSIVELY CONNECTED TO SAID THIRD MEANS FOR ALTERNATIVELY ACTIVATING SAID COARSE CONTROL PRESSURE CHANNEL OR SAID FINE CONTROL PRESSURE CHANNEL, SAID SWITCH MEANS BEING CONNECTED BETWEEN SAID CHANNELS AND SAID DIFFERENCE DERIVING MEANS TO ALTERNATIVELY ACTIVATE SAID COARSE CONTROL CHANNEL IN RESPONSE TO OUTPUTS FROM SAID DIFFERENCE DERIVING MEANS GREATER IN MAGNITUDE THAN A PREDETERMINED MINIMUM VALUE OR SAID FINE CONTROL CHANNEL IN RESPONSE TO OUTPUTS FROM SAID DIFFERENCE DERIVING MEANS LESS IN MAGNITUDE THAN SAID PREDETERMINED MINIMUM VALUE, AND AN OUTPUT LINE, THE OUTPUTS OF SAID FINE AND COARSE CONTROL PRESSURE CHANNELS BEING FED TO SAID OUTPUT LINE.