초록 ▼

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 the

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.

대표청구항 ▼

A signal generating circuit useful in determining the value of a capacitor and including: a charging source including a resistive element; a plurality of switches, each switch being positionable between a first, open position and a second, closed position in response to logic signals, said switches

A signal generating circuit useful in determining the value of a capacitor and including: a charging source including a resistive element; a plurality of switches, each switch being positionable between a first, open position and a second, closed position in response to logic signals, said switches thereby being controllable for sequentially connecting a first reference capacitor of known value and a second capacitor to said resistive element for charging said capacitors to a potential; an oscillating comparator network for establishing a trigger reference voltage and generating a clocking pulse when the sequentially detected charge potential of said capacitors is equal to said trigger reference voltage; a logic network connected to said comparator network for generating said logic signals in response to said clocking pulse, said logic network including a network for resetting said signal generating circuit, and; means for determining a first time required to charge said first capacitor from an initially-depleted state to said trigger reference voltage and for determining a second time required to charge said second capacitor from an initially-depleted state to said trigger reference voltage.