Square root circuit with stable linear cut-off

摘要

A square root circuit is provided with a high gain amplifier for receiving the input and a squaring circuit in the negative feedback circuit of the amplifier to produce the desired square root output. A second negative feedback path is provided with a feedback resistor and switching means for selectively completing the connection of the second feedback path when the amplifier input falls below a certain predetermined level so that the amplifier provides a linear response in the low input region. This linear response will make the accurate setting of the zero possible without any manual switching in the amplifier feedback.