Patent US3015403A successfully refreshed from Google Patents.
Patent US3579227A successfully refreshed from Google Patents.
US3579227A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital-to-analog converter system
Assignee: Louis Allis Co
•
Filing: 1968-05-17
•
Granted: 1971-05-18
•
Expires: 1988-05-17
Abstract
Abstract The D/A converter system includes a positive D/A converter and a negative D/A converter having common outputs connected to ground. Logic circuitry provided for each D/A converter is responsive to a polarity control signal for disabling one D/A converter from producing an analog output signal of one polarity while enabling the other D/A converter to produce an analog output signal of the other polarity in response to a digital input signal from a digital controller. Power supplies bias the positive and negative D/A converters to isolate the analog output signal generated by the enabled D/A converter from the disabled D/A converter.
Inventors
- 👤 James W Appelgren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:17
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/27; H; H03; H03M; H03M1/00; H03M1/06; H03M1/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
135 words
A D/A converter system, which comprises: a first means for converting a digital input signal into a first analog voltage output signal having a selected polarity with respect to ground; a second means for converting a digital input signal into a second analog voltage output signal having the other polarity with respect to ground, said first and second means being connected to a common grounded output circuit; logic means coupled to said first and second converting means for disabling said first means and for enabling said second means to generate said second analog voltage output signal; and voltage responsive means interposed in the output of said first converting means for isolating said second converting means from said first converting means to permit said second analog voltage output signal to pass to said common output circuit.
Claim 2
Dependent Claim
135 words
A D/A converter system, which comprises: a first means for converting a digital input signal into a first analog voltage output signal having a selected polarity with respect to ground; a second means for converting a digital input signal into a second analog voltage output signal having the other polarity with respect to ground, said first and second means being connected to a common grounded output circuit; logic means coupled to said first and second converting means for disabling said first means and for enabling said second means to generate said second analog voltage output signal; and voltage responsive means interposed in the output of said first converting means for isolating said second converting means from said first converting means to permit said second analog voltage output signal to pass to said common output circuit.
Claim 3
Dependent Claim
58 words
A D/A converter system according to claim 1 wherein said isolation means comprises a diode connected between said first converting means and said output circuit and poled to conduct said first analog voltage output signal, said isolating means further comprising a bias means coupled to said diode for applying bias voltage thereto for biasing said diode against conduction.
Claim 4
Dependent Claim
61 words
A D/A converter system according to claim 2 further comprising a means for limiting the level of said second analog voltage output signal to a level sufficient, with respect to the bias voltage applied to said diode by said bias means, as to maintain said diode nonconductive, so that said second analog voltage output signal passes to said common output circuit.
Claim 5
Dependent Claim
236 words
A D/A converter system for converting a digital input signal to a system analog voltage output signal having a first or second polarity with respect to ground responsive to a bistate polarity control signal, the state of which is indicative of the desired polarity of the system analog voltage output signal, said system comprising; a first D/A converter for generating a first analog voltage output signal having a first polarity with respect to ground; a second D/A converter for generating a second analog voltage output signal having a second polarity with respect to ground; said first and second D/A converters being connected across diodes to a common grounded output circuit in which said system analog voltage output signal appeaRs, said diodes being poled to conduct the analog voltage output signal from the D/A converter to which they are connected; logic means coupled to said first and second converter means, said logic means being operable by the state of the polarity control signal for disabling said first converter and enabling said second converter responsive to a signal state indicative of said second polarity system analog output signal, said logic means being further operable by said digital input signal to render said second D/A converter effective to generate said second polarity analog output signal; and means coupled to said diode connected to said first D/A converter for applying a bias voltage thereto for biasing the diode against conduction.
Claim 6
Dependent Claim
236 words
A D/A converter system for converting a digital input signal to a system analog voltage output signal having a first or second polarity with respect to ground responsive to a bistate polarity control signal, the state of which is indicative of the desired polarity of the system analog voltage output signal, said system comprising; a first D/A converter for generating a first analog voltage output signal having a first polarity with respect to ground; a second D/A converter for generating a second analog voltage output signal having a second polarity with respect to ground; said first and second D/A converters being connected across diodes to a common grounded output circuit in which said system analog voltage output signal appeaRs, said diodes being poled to conduct the analog voltage output signal from the D/A converter to which they are connected; logic means coupled to said first and second converter means, said logic means being operable by the state of the polarity control signal for disabling said first converter and enabling said second converter responsive to a signal state indicative of said second polarity system analog output signal, said logic means being further operable by said digital input signal to render said second D/A converter effective to generate said second polarity analog output signal; and means coupled to said diode connected to said first D/A converter for applying a bias voltage thereto for biasing the diode against conduction.
Claim 7
Dependent Claim
63 words
A D/A converter system according to claim 4 further comprising a means for limiting the level of said second analog voltage output signal to a level sufficient, with respect to the bias voltage applied to said first D/A converter diode by said bias means, as to maintain said diode nonconductive, so that second analog voltage output signal passes to said common output circuit.
Claim 8
Dependent Claim
51 words
A D/A converter system according to claim 4 further including means for substantially instantaneously changing the state of said polarity control signal to a state indicative of the opposite polarity, said logic means being responsive to said changed polarity control for substantially instantaneously disabling said converter and enabling said first converter.
Claim 9
Independent Claim
463 words
A system for converting a digital input signal to a system analog voltage output signal having a positive and a negative polarity with respect to ground, wherein the digital input signal has a logical 1 state and a logical 0 state for a given digital channel, said system comprising: a grounded system analog output circuit for providing said system analog voltage output signal; a first D/A converter for generating a positive analog output voltage signal, said converter including a first transistor having an output circuit and an input circuit for controlling the ON-OFF state of said output circuit, and means for biasing the input circuit thereof to place the output circuit of said first transistor in an ON state to prevent generation of a positive analog output voltage signal; a first output diode connected between said first transistor output circuit and said system analog output circuit; means connected to the output circuit of said first transistor for applying a diode control signal having a selected level with respect to the system analog voltage output signal for rendering said diode nonconductive to isolate said first D/A converter from said system analog output circuit; a second D/A converter for generating a negative analog output voltage signal, said converter including a second transistor having an output circuit and an input circuit for controlling the ON-OFF state of said output circuit, and means for biasing the input circuit thereof to place said output circuit in the ON state to prevent generation of a negative analog output voltage signal; means for producing a polarity control signal; a logic circuit coupled to the input circuit of said first transistor and to said polarity control signal means and responsive to said polarity control signal for maintaining the output circuit of said first transistor in the ON state to prevent generation of said positive analog output signal; a logic circuit to the input circuit of said second transistor and said polarity control signal means and responsive to said polarity control signal and to the digital input signal having a logical 1 state for placing the output circuit of said second transistor in the OFF state to enable said D/A converter to generate said negative analog output signal; a second output diode connected between said second transistor output circuit and said system analog output circuit; analog biasing means connected to the output circuit of said second transistor for forwardly biasing said second diode to apply said negative analog output signal to said system analog output circuit; and means for limiting said negative analog output signal to a level less than said selected level of said diode control signal so that said diode control signal is effective to maintain said first diode back biased during the generation of said negative analog output signal.
Claim 10
Independent Claim
463 words
A system for converting a digital input signal to a system analog voltage output signal having a positive and a negative polarity with respect to ground, wherein the digital input signal has a logical 1 state and a logical 0 state for a given digital channel, said system comprising: a grounded system analog output circuit for providing said system analog voltage output signal; a first D/A converter for generating a positive analog output voltage signal, said converter including a first transistor having an output circuit and an input circuit for controlling the ON-OFF state of said output circuit, and means for biasing the input circuit thereof to place the output circuit of said first transistor in an ON state to prevent generation of a positive analog output voltage signal; a first output diode connected between said first transistor output circuit and said system analog output circuit; means connected to the output circuit of said first transistor for applying a diode control signal having a selected level with respect to the system analog voltage output signal for rendering said diode nonconductive to isolate said first D/A converter from said system analog output circuit; a second D/A converter for generating a negative analog output voltage signal, said converter including a second transistor having an output circuit and an input circuit for controlling the ON-OFF state of said output circuit, and means for biasing the input circuit thereof to place said output circuit in the ON state to prevent generation of a negative analog output voltage signal; means for producing a polarity control signal; a logic circuit coupled to the input circuit of said first transistor and to said polarity control signal means and responsive to said polarity control signal for maintaining the output circuit of said first transistor in the ON state to prevent generation of said positive analog output signal; a logic circuit to the input circuit of said second transistor and said polarity control signal means and responsive to said polarity control signal and to the digital input signal having a logical 1 state for placing the output circuit of said second transistor in the OFF state to enable said D/A converter to generate said negative analog output signal; a second output diode connected between said second transistor output circuit and said system analog output circuit; analog biasing means connected to the output circuit of said second transistor for forwardly biasing said second diode to apply said negative analog output signal to said system analog output circuit; and means for limiting said negative analog output signal to a level less than said selected level of said diode control signal so that said diode control signal is effective to maintain said first diode back biased during the generation of said negative analog output signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |