Frequency adjustment circuit
AssigneeFairchild Camera and Instrument Corporation
InventorsDonald R. Duff, James O. Lamb, Donald E. Pezzolo
Life of this patent
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Abstract
A circuit for adjusting the frequency of operation of an electronic time keeping device, which device includes a source of clock pulses. The circuit of this invention is preferably located between the source of clock pulses and the time keeping device counting circuitry, so that the clock pulses can be periodically interrupted for a programmed amount of time. Accordingly, the variable adjustment capacitor, typically employed in prior art time keeping devices, can be eliminated.
Claims8
A circuit for adjusting the frequency of operation of an electronic time keeping device including a source of clock pulses, said circuit comprising:
- a. means for storing a numeric code representative of a time delay of said clock pulses having a plurality of data output terminals;
- b. means for counting a time interval in proportion to said numeric code, including a plurality of data input terminals coupled to respective ones of said data output terminals of said means for storing, a plurality of data output terminals, and a clock input terminal;
- c. circuit means having a first input coupled to the source of clock pulses, a first clock output terminal coupled to the clock input terminal of said means for counting, a plurality of data input terminals coupled to respective ones of said data output terminals of said means for counting and a second clock output terminal disposed for supplying clock pulses of an adjusted frequency to the electronic time keeping device.
A method of adjusting the frequency of operation of an electronic time keeping device, which device includes a source of clock pulses, comprising the steps of:
- a. inserting a numeric code into a progammable counter;
- b. storing the numeric code in the programmable counter;
- c. displaying the numeric code stored;
- d. transferring the numeric code to a time delay counter;
- and
- e. supplying signals from the time delay counter to a gating network to thereby interrupt the source of clock pulses at desired intervals.
Dependencies are inferred from the claim text.