| 摘要 |
A signal generating circuit useful in determining the value of a capacitor includes a charging source having a resistive element and a plurality of switches, each switch being positionable between a first, open position and a second, closed position in response to logic signals. The switches are thereby controllable for sequentially connecting a first reference capacitor of known value and a second capacitor to the resistive element for charging said capacitors to a potential. An oscillating comparator network establishes a trigger reference voltage and generates a clocking pulse when the sequentially detected charge potential of the capacitors is equal to the trigger reference voltage. A logic network is connected to the comparator network for generating the logic signals in response to the clocking pulse and the logic network includes a network for resetting the signal generating circuit. Also included is means for determining a first time required to charge the first capacitor from an initially-depleted state to the trigger reference voltage and for determining a second time required to charge the second capacitor from an initially-depleted state to the trigger reference voltage. A method for determining the value of a capacitance is also disclosed.
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