Systems involving division

Claim 1

In a system involving division, wherein said system has an amplifier having high gain before feedback and a negative feedback loop interconnecting said amplifier''s input and output for causing said amplifier to produce a first signal at its said output substantially in proportion to a second signal applied to its said input, said feedback loop having an element therein variable in response to a third signal applied thereto for causing said amplifier to produce said first signal in proportion to the magnitude of said second signal divided by the magnitude of said third signal, and wherein said feedback loop has the property of providing no feedback as a result of variation of said feedback element in response to said third signal having substantially zero magnitude, and wherein said system has signal producing means connected to said feedback element for applying said third signal to said feedback element, and said signal producing means has the property of, on occasion, providing said third signal at substantially zero magnitude, the improvement comprising a second feedback element connected between said output and input of said amplifier independently of said first feedback element, said second feedback element being actuable between first and second states, said first state being one in which said second feedback element is ineffective to provide feedback of said output to said input, and said second state being one in which said second feedback element is effective to provide DC feedback of output to input, said second feedback element being normally in said first state; and control means operative when the magnitude of said third signal is substantially zero to actuate said second feedback element to said second state.