Zeroing circuit

An offset compensating circuit for automatically adjusting the input signal level of an electronic circuit having an input and an output to produce an output signal of a predetermined level in response to a predetermined input signal condition, said offset compensating circuit comprising:

• A. an amplifier having an input and an output, said input being coupled to receive the output signal from the electronic circuit;
• B. a first feedback loop, said first feedback loop being connected between said output of said amplifier and the input to the electronic circuit, said first feedback loop including:
• 1. a first capacitor having first and second plates;
• 2. first electronic switch means connected between said output of said amplifier and said first plate of said first capacitor;
• 3. means connecting said second plate of said first capacitor to a voltage reference;
• and
• 4. coupling means electrically disposed between said first plate of said first capacitor and the input to the electronic circuit;
• C. a second feedback loop, said second feedback loop being connected between said output and said input of said amplifier, said second feedback loop including:
• 1. a resistor;
• and
• 2. a second electronic switch disposed in series with said resistor;
• and
• D. means for intermittently generating switching signals to switch said first and second electronic switch means to be alternatively closed in a timed relationship.