US3609395A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency to voltage converter circuit
Assignee: Ford Motor Co
•
Filing: 1970-09-02
•
Granted: 1971-09-28
•
Expires: 1990-09-02
Abstract
Abstract An improved frequency to voltage conversion circuit is described. The unimproved basic circuit comprises a transistor, two capacitors, a resistor, and a diode. The improved circuit includes transistor means connected to the base of the transistor in the basic circuit to provide temperature compensation and to reduce or eliminate transient conditions. Additional transistors, diodes, and resistors are provided to effect protection against supply voltage transients, to provide additional temperature compensation where necessary, to assure the presence of an adequate signal to operate the frequency to voltage converter, and to provide the overall circuit with a high input impedance and a low output impedance.
Inventors
- 👤 Zbigniew J Jania
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:53
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/06
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
125 words
A circuit for the conversion of a periodic electrical signal to a signal having an average voltage proportional to the frequency of the periodic electrical signal, which comprises: a first transistor; a first capacitor having one of its terminals connected to the emitter of said first transistor and having the periodic electrical signal applied to its other terminal; a second capacitor; a resistor connected in parallel with said second capacitor; a diode connected between the emitter of said first transistor and one of the terminals of said second capacitor; and transistor means connected to the base of said first transistor for causing the voltage applied thereto to exceed in absolute value the value of the voltage existing at said one terminal of said second capacitor.
Claim 2
Dependent Claim
125 words
A circuit for the conversion of a periodic electrical signal to a signal having an average voltage proportional to the frequency of the periodic electrical signal, which comprises: a first transistor; a first capacitor having one of its terminals connected to the emitter of said first transistor and having the periodic electrical signal applied to its other terminal; a second capacitor; a resistor connected in parallel with said second capacitor; a diode connected between the emitter of said first transistor and one of the terminals of said second capacitor; and transistor means connected to the base of said first transistor for causing the voltage applied thereto to exceed in absolute value the value of the voltage existing at said one terminal of said second capacitor.
Claim 3
Dependent Claim
80 words
A circuit in accordance with claim 1, wherein said transistor means comprises a second transistor having its emitter connected to the base of said first transistor and its base connected to said one terminal of said second capacitor, thereby to cause the voltage applied to the base of said first transistor to exceed, by an amount approximately equal to the emitter-to-base voltage of said second transistor, the value of the voltage existing at said one terminal of said second capacitor.
Claim 4
Dependent Claim
36 words
A circuit in accordance with claim 2, which further includes: a third transistor having its base connected to the emitter of said second transistor; and an output resistance connected to the emitter of said third transistor.
Claim 5
Dependent Claim
31 words
A circuit in accordance with claim 2, wherein said second transistor has a high gain to provide the frequency-to-voltage converter circuit with a high input impedance and a low output impedance.
Claim 6
Dependent Claim
35 words
A circuit in accordance with claim 2, which further includes resistance means connected in electrical circuit with said second transistor for providing an output voltage inversely proportional to the frequency of the periodic electrical signal.
Claim 7
Dependent Claim
187 words
A circuit for the conversion of a periodic electrical input signal to a signal having an average voltage proportional to the frequency of the periodic input signal, which comprises: a first transistor, the periodic input signal being applied between the base and the emitter of said first transistor to cause said first transistor to change from a conductive to a nonconductive state and back to a conductive state in response to the variation of the periodic electrical input signal; a second transistor; a first capacitor having one of its terminals connected to the emitter of said second transistor and its other terminal connected to the collector of said first transistor; a second caPacitor; a resistor connected in parallel with said second capacitor; a first diode connected between the emitter of said second transistor and one of the terminals of said second capacitor; and transistor means connected to the base of said second transistor to cause the voltage applied thereto to exceed in absolute value the value of the voltage existing at said one terminal of said second capacitor when said first transistor is in a conductive state.
Claim 8
Dependent Claim
187 words
A circuit for the conversion of a periodic electrical input signal to a signal having an average voltage proportional to the frequency of the periodic input signal, which comprises: a first transistor, the periodic input signal being applied between the base and the emitter of said first transistor to cause said first transistor to change from a conductive to a nonconductive state and back to a conductive state in response to the variation of the periodic electrical input signal; a second transistor; a first capacitor having one of its terminals connected to the emitter of said second transistor and its other terminal connected to the collector of said first transistor; a second caPacitor; a resistor connected in parallel with said second capacitor; a first diode connected between the emitter of said second transistor and one of the terminals of said second capacitor; and transistor means connected to the base of said second transistor to cause the voltage applied thereto to exceed in absolute value the value of the voltage existing at said one terminal of said second capacitor when said first transistor is in a conductive state.
Claim 9
Dependent Claim
38 words
A circuit in accordance with claim 6, which further includes resistance and diode means connected to the base of said first transistor to assure its change of state in response to variation of said periodic electrical input signal.
Claim 10
Dependent Claim
36 words
A circuit in accordance with claim 6, which further includes resistance means connected in electrical circuit with said third transistor for providing an output voltage inversely proportional to the frequency of the periodic electrical input signal.
Claim 11
Dependent Claim
81 words
A circuit in accordance with claim 6, wherein said transistor means comprises a third transistor having its emitter connected to the base of said second transistor and having its base connected to said one terminal of said second capacitor, thereby, to cause the voltage applied to the base of said second transistor to exceed, by an amount approximately equal to the emitter-to-base voltage of said third transistor, the value of the voltage existing at said one terminal of said second capacitor.
Claim 12
Dependent Claim
46 words
A circuit in accordance with claim 9, which further includes: a fourth transistor having its base connected to the emitter of said third transistor; and an output load resistance connected to the emitter of said fourth transistor, the voltage output being taken across said load resistance.
Claim 13
Dependent Claim
38 words
A circuit in accordance with claim 10, which further includes resistance and diode means connected to the base of said first transistor to assure its change of state in response to variation of said periodic electrical input signal.
Claim 14
Dependent Claim
138 words
In a circuit for the conversion of a periodic electrical signal to a signal having an average voltage proportional to the frequency of the periodic signal, the circuit comprising a transistor, a first capacitor having one of its terminals connected to the emitter of said first transistor and having the periodic electrical signal applied to its other terminal, a second capacitor, a resistor connected in parallel with said second capacitor, and a diode connected between the emitter of said first transistor and one of the terminals of said second capacitor; the improvement which comprises: means for raising the absolute value of the voltage applied to the base of said transistor above the voltage existing at said one terminal of said second capacitor; and means for providing said circuit with a high input impedance and a low output impedance.
Claim 15
Dependent Claim
138 words
In a circuit for the conversion of a periodic electrical signal to a signal having an average voltage proportional to the frequency of the periodic signal, the circuit comprising a transistor, a first capacitor having one of its terminals connected to the emitter of said first transistor and having the periodic electrical signal applied to its other terminal, a second capacitor, a resistor connected in parallel with said second capacitor, and a diode connected between the emitter of said first transistor and one of the terminals of said second capacitor; the improvement which comprises: means for raising the absolute value of the voltage applied to the base of said transistor above the voltage existing at said one terminal of said second capacitor; and means for providing said circuit with a high input impedance and a low output impedance.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |