Analog to digital converters having multiple units of measurement

Claim 2

A converter for registering an analog quantity in digital form, said quantity being registered in either of at least two different units of measurement, said converter comprising: means for selecting either a first or a second unit of measurement; first counter means for registering said analog quantity in only said first unit of measurement; second counter means for registering said analog quantity in said first unit of measurement when said first unit has been selected by said selecting means and in said second unit when said second unit has been selected by said selecting means; digital to analog converter means, connected to said first counter, for converting the contents of said first counter to a first analog signal; comparing means, connected to said digital to analog converter, for comparing said first analog signal with said analog quantity, said means for selecting being operatively connected to said comparing means; and, means for incrementing said first and said second counters, connected between said counters and said means for selecting, said incrementing means including means for supplying a count to said first counter which differs from the count supplied to said second counter when said second unit of measurement has been selected by said selecting means.

Claim 3

A converter according to claim 1 wherein said means for incrementing said counters includes means for incrementing upper or lower decades of said counters depending on the magnitude of the difference between said analog quantity and said first analog signal.

Claim 4

A converter according to claim 1 wherein said counters are bidirectional.

Claim 5

An analog to digital converter for registering an analog input signal in either of two different units of measurement, said units being related by a conversion factor, said converter, comprising: means for comparing said analog input signal with a feedback analog signal to produce an analog error signal; unit selection means having a first unit position and a second unit position and including transforming means for altering the magnitude of said error signal by said conversion factor when said unit selection means is in said second unit position; a first counter means for registering the magnitude of said analog input signal in said first unit of measurement regardless of the position of said unit selection means; a second counter means for registering the magnitude of said analog input signal in said first unit of measurement when said first unit position has been selected and in said second unit of measurement when said second unit position has been selected; means for incrementing said counters connected between said unit selection means and said counters; and digital to analog converter means, connected between said comparing means and said first counter, for providing said feedback signal in accordance with the count in said first counter.

Claim 6

An analog to digital converter for registering an analog input signal in either of two different units of measurement, said units being related by a conversion factor, said converter, comprising: means for comparing said analog input signal with a feedback analog signal to produce an analog error signal; unit selection means having a first unit position and a second unit position and including transforming means for altering the magnitude of said error signal by said conversion factor when said unit selection means is in said second unit position; a first counter means for registering the magnitude of said analog input signal in said first unit of measurement regardless of the position of said unit selection means; a second counter means for registering the magnitude of said analog input signal in said first unit of measurement when said first unit position has been selected and in said second unit of measurement when said second unit position has been selected; means for incrementing said counters connected between said unit selection means and said counters; and digital to analog converter means, connected between said comparing means and said first counter, for providing said feedback signal in accordance with the count in said first counter.

Claim 7

A converter for registering an analog input signal in either of two units of measurement, said units being related by a factor of conversion, said converter comprising: means for comparing said analog input signal with a feedback analog signal to produce an error analog signal; unit selector means for selecting between said two units of measurement, said selector including means for transforming the magnitude of said error signal in accordance with said factor of conversion, said unit selector connected to an output of said comparing means; control means, connected to an output of said unit selector; means for generating counting and timing pulses; a first counter means, connected to said means for generating, for counting pulses in only one of said two units of measurement; a second counter means, connected to said means for generating, for counting pulses in a first one of said two units of measurement when said first unit has been selected by said selector and in a second of said two units when said second units has been selected; means connecting said control means to said first and second counter; means connecting said unit selector to said first counter; and digital to analog converter means, connected between said first counter and said comparing means, for producing said feedback signal.

Claim 8

A converter for registering an analog input signal in either of two units of measurement, said units being related by a factor of conversion, said converter comprising: means for comparing said analog input signal with a feedback analog signal to produce an error analog signal; unit selector means for selecting between said two units of measurement, said selector including means for transforming the magnitude of said error signal in accordance with said factor of conversion, said unit selector connected to an output of said comparing means; control means, connected to an output of said unit selector; means for generating counting and timing pulses; a first counter means, connected to said means for generating, for counting pulses in only one of said two units of measurement; a second counter means, connected to said means for generating, for counting pulses in a first one of said two units of measurement when said first unit has been selected by said selector and in a second of said two units when said second units has been selected; means connecting said control means to said first and second counter; means connecting said unit selector to said first counter; and digital to analog converter means, connected between said first counter and said comparing means, for producing said feedback signal.

Claim 9

The converter according to claim 5 wherein said control means includes means for selecting a coarse or fine count mode for said first and second counters depending on the magnitude of said analog error signal.

Claim 10

The converter according to claim 5 wherein said counters are bidirectional and said control means includes means for controlling the direction of count. 8. An analog to digital converter having a conversion cycle, said converter comprising: means for comparing an input analog signal with a second analog signal to produce an error signal; a unit of measurement selection means for selecting between at least a first and a second unit of measurement, said selection means being connected to said comparing means; a first counting means for registering in digital form an input analog signal, said first counting means always operating in said first measurement unit choice; a second counting means for registering in digital form the input analog signal, said second counting means operating in said first measurement unit choice when said first unit has been selected by said selection means and in said second unit when said second unit has been selected; first logic means for passing a number of counting pulses to said first counter during said conversion cycle, said number being dependent upon said measurement unit choice, said selection means being connected to said first logic means; second logic means for passing a single pulse to said second counter during said conversion cycle regardless of said measurement unit choice; and a digital to analog converter connected between said first counter and said comparing means for producing said second analog signal.