Analog signal to frequency signal converter

Claim 2

A multiplier circuit for providing an output frequency signal having a Frequency proportional to the product of functions of first and second analog signals, and comprising: first analog to frequency signal converting means for receiving a said first analog signal and providing a first frequency signal exhibiting a frequency proportional to a function of said first analog signal; second analog to frequency signal converting means for receiving said second analog signal and said first frequency signal and providing therefrom a second frequency signal having a frequency proportional to the product of a function of said first signal and a function of said second analog signal, said second converting means includes charging circuit means having energy storage means for receiving said second analog signal for charging said energy storage means at a rate dependent on the magnitude of said second analog signal, and means for providing an output signal when the storage means is charged to a predetermined level; means responsive to said output signal and to said first frequency signal for discharging said energy storage means for a time period inversely proportional to the frequency of said first output frequency signal so that said output signal serves as said second output frequency signal.

Claim 3

A multiplier circuit as set forth in claim 1, wherein said discharging means includes: a reference source of energy; actuatable switching means for, when actuated, connecting said source with said storage means to discharge said storage means, and switch control means for actuating said switching means to discharge said storage means for a time period dependent upon the frequency of said first output frequency signal.

Claim 4

A multiplier circuit as set forth in claim 2, wherein said switch control means includes circuit means for actuating said switching means only in response to the concurrent occurrence of a said first frequency signal and a said output signal.

Claim 5

A multiplier circuit as set forth in claim 3, wherein said circuit means includes means for preventing actuation of said switching means unless said output signal is received before that of said first frequency signal.

Claim 6

A multiplier circuit as set forth in claim 2, wherein said switch control means includes means for timing said time period so as to be inversely proportional to the frequency of said first output frequency signal.

Claim 7

A multiplier circuit as set forth in claim 5, wherein said timing means includes pulse counter means for counting a predetermined number of signal pulses occurring at the frequency of said first output frequency signal and providing an output indication when said predetermined number of pulses have been counted.

Claim 8

A multiplier circuit as set forth in claim 6, including circuit means controlled by said counter means for actuating said switching means during the counting operation until said counter means provides a said output indication.

Claim 9

A multiplier circuit as set forth in claim 7, wherein said first analog to frequency signal converter means includes an energy storage means for storing energy at a rate dependent on the magnitude of said first analog signal, comparing means for providing an output pulse signal when the energy stored by storage means attains a predetermined level, and discharge circuit means responds to each said output pulse signal for discharging said energy storage means at a substantially constant rate and for a fixed period of time.

Claim 10

An analog to frequency signal converter comprising: charging circuit means including energy storage means for receiving an analog signal for charging said energy storage means at a rate dependent upon the magnitude of said analog signal; means for providing an output signal pulse when said storage means is charged to a predetermined level; means for providing a frequency signal; and means responsive to said output signal pulse and to said frequency signal for discharging said energy storage means at a substantially constant rate for a time period inveRsely proportional to the frequency of said frequency signal so that the said output signal pulse occurs at a frequency dependent on the magnitude of said analog signal and the frequency of said frequency signal.

Claim 11

An analog to frequency signal converter comprising: charging circuit means including energy storage means for receiving an analog signal for charging said energy storage means at a rate dependent upon the magnitude of said analog signal; means for providing an output signal pulse when said storage means is charged to a predetermined level; means for providing a frequency signal; and means responsive to said output signal pulse and to said frequency signal for discharging said energy storage means at a substantially constant rate for a time period inveRsely proportional to the frequency of said frequency signal so that the said output signal pulse occurs at a frequency dependent on the magnitude of said analog signal and the frequency of said frequency signal.

Claim 12

A multiplier circuit for providing an output frequency signal having a frequency proportional to the product of a first analog signal and N analog signals, where N is at least 2, and comprising: first analog to frequency signal converting means for receiving a said first analog signal and providing a first output frequency signal exhibiting a frequency proportional to the magnitude of said first analog signal; N second analog signal to frequency converting means for respectively receiving an associated one of N analog signals, each said second converting means including: charging circuit means including energy storage means for receiving an associated one of said N analog signals for charging said energy storage means at a rate dependent on the magnitude of said associated signal; means for providing an output signal when said storage means is charged to a predetermined level; and means responsive to said output signal and to said first output frequency signal for discharging said energy storage means at a substantially constant rate for a time period inversely proportional to the frequency of said first output frequency signal so that said output signal exhibits a frequency proportional to the product of said first analog signal and said associated analog signal; and circuit means for applying the output signal of a preceding one of said second converting means to the output signal responsive means of the next succeeding second converting means.

Claim 13

A multiplier circuit for providing an output frequency signal having a frequency proportional to the product of a first analog signal and N analog signals, where N is at least 2, and comprising: first analog to frequency signal converting means for receiving a said first analog signal and providing a first output frequency signal exhibiting a frequency proportional to the magnitude of said first analog signal; N second analog signal to frequency converting means for respectively receiving an associated one of N analog signals, each said second converting means including: charging circuit means including energy storage means for receiving an associated one of said N analog signals for charging said energy storage means at a rate dependent on the magnitude of said associated signal; means for providing an output signal when said storage means is charged to a predetermined level; and means responsive to said output signal and to said first output frequency signal for discharging said energy storage means at a substantially constant rate for a time period inversely proportional to the frequency of said first output frequency signal so that said output signal exhibits a frequency proportional to the product of said first analog signal and said associated analog signal; and circuit means for applying the output signal of a preceding one of said second converting means to the output signal responsive means of the next succeeding second converting means.