Digital rate meter

Claim 2

In a digital rate meter for approximating the frequency of a repeatable function, the repeatable function frequency being lower than a first predetermined frequency, of the type having clock pulse generator means and register means responsive to said clock pulse generator means, the improvement which comprises: said clock pulse generator means being selectively sequentially operable at first and successive clock pulse repetition rates, said first repetition rate being substantially equal to 1/n times the increase in period resulting from a decrease in frequency from said first predetermined frequency to a second lower frequency, n being a constant number greater than 1, with said successive repetition rates being substantially equal to 1/n times the increase in period from successive decreases in frequency, each successive decrease in frequency being substantially equal to the decrease in frequency from said first predetermined frequency to said second lower frequency; and means responsive to said clock pulse generator means for sequentially switching said clock pulse generator means from said first repetition rate through said successive repetition rates, said switching being effected after n pulses at each repetition rate.

Claim 3

The digitAl rate meter improvement of claim 1 wherein said clock pulse generator means comprises: pulse generator means of the type having an RC time constant; and network means having a plurality of time constant altering means each independently connectable to said pulse generator time constant; said means for sequentially switching comprising switch means for sequentially connecting a different one of said time constant altering means to said pulse generator time constant after n pulses have been generated by said pulse generator means.

Claim 4

The digital rate meter improvement of claim 2 wherein each of said time constant altering means comprises first resistance means.

Claim 5

The digital rate meter improvement of claim 3 wherein each of said time constant altering means further comprises serially connected capacitances and second resistance means connected in parallel with said first resistance means.

Claim 6

The digital rate meter improvement of claim 4 wherein said register means comprises down-counter means, the improvement further comprising means for presetting said down-counter means to a count substantially equal to said first predetermined frequency.

Claim 7

The digital rate meter improvement of claim 5 wherein n equals the difference in frequency between said first predetermined frequency and said second lower frequency.

Claim 8

The digital rate meter improvement of claim 1 wherein said clock pulse generator means comprises a plurality of pulse generator means each having a pulse repetition rate corresponding to one of said first and successive repetition rates, each of said pulse generator means being selectively connectable to said register means and said sequentially switching means comprising means for connecting a different one of said pulse generator means to said register means after the connected pulse generator means has generated n pulses.

Claim 9

The digital rate meter improvement of claim 7 wherein said register means comprises down-counter means, the improvement further comprising means for presetting said down-counter means to a count substantially equal to said first predetermined frequency.

Claim 10

The digital rate meter improvement of claim 8 wherein n equals the difference in frequency between said first predetermined frequency and said second lower frequency.

Claim 13

The method of claim 10 wherein the step of registering comprises the step of counting down from a predetermined number in response to said signal, said predetermined number being the frequency of said first frequency.

Claim 14

The method of claim 11 wherein n equals the difference in frequency between said first and second frequency, the step of generating n signals comprising the steps of generating signals at intervals equal to the difference in period between said first and second frequencies divided by the difference in frequency between said first and second frequency.

Claim 15

A digital rate meter for approximating the frequency of a repeatable function, the repeatable function frequency being lower than a first predetermined frequency, which comprises; clock pulse generator means selectively sequentially operable at first and successive clock pulse repetition rates, said first repetition rate being substantially equal to 1/n times the increase in period resulting from a decrease in frequency from said first predetermined frequency to a second lower frequency, n being a constant number greater than 1, with said successive repetition rates substantially equal to 1/n times the increase in period from successive decreases in frequency, each successive decrease in frequency being substantially equal to the decrease in frequency from said first predetermined frequency to said second lower frequency; means for counting down from a predetermined count equal to the frequency of said first predetermined frequency in response to pulses from said clock pulse generator means; storage means connected to said down counting means; input means including a monostable multivibrator, the pulse length of said monostable multivibrator being equal to the period of said first predetermined frequency; means for generating a storage means closk pulse upon the rising edge of a pulse from said monostable multivibrator, said storage means clock pulse being applied to said storage means for causing it to accept the count of said down counting means; means for generating a down counting means pre-set pulse upon the falling edge of a pulse from said monostable multivibrator, said down counting means pre-set pulse being applied to said down counting means to pre-set it to said predetermined count; and means responsive to said clock pulse generator means for sequentially switching said clock pulse generator means through said successive repetition rates, said switching being effected after n pulses at each repetition rate.

Claim 16

A digital rate meter for approximating the frequency of a repeatable function, the repeatable function frequency being lower than a first predetermined frequency, which comprises; clock pulse generator means selectively sequentially operable at first and successive clock pulse repetition rates, said first repetition rate being substantially equal to 1/n times the increase in period resulting from a decrease in frequency from said first predetermined frequency to a second lower frequency, n being a constant number greater than 1, with said successive repetition rates substantially equal to 1/n times the increase in period from successive decreases in frequency, each successive decrease in frequency being substantially equal to the decrease in frequency from said first predetermined frequency to said second lower frequency; means for counting down from a predetermined count equal to the frequency of said first predetermined frequency in response to pulses from said clock pulse generator means; storage means connected to said down counting means; input means including a monostable multivibrator, the pulse length of said monostable multivibrator being equal to the period of said first predetermined frequency; means for generating a storage means closk pulse upon the rising edge of a pulse from said monostable multivibrator, said storage means clock pulse being applied to said storage means for causing it to accept the count of said down counting means; means for generating a down counting means pre-set pulse upon the falling edge of a pulse from said monostable multivibrator, said down counting means pre-set pulse being applied to said down counting means to pre-set it to said predetermined count; and means responsive to said clock pulse generator means for sequentially switching said clock pulse generator means through said successive repetition rates, said switching being effected after n pulses at each repetition rate.