US3564296A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Waveform shaping circuit comprising a unijunction transistor and zener diode
Assignee: GTE Sylvania Inc
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Filing: 1968-07-19
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Granted: 1971-02-16
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Expires: 1988-07-19
Abstract
Abstract A circuit for converting an input voltage waveform having a magnitude which varies slowly with time to a substantially rectangular voltage pulse having a steep leading edge. The output pulse is initiated when the input voltage falls below a first predetermined magnitude and is terminated when the input voltage increases above a second predetermined magnitude. In one embodiment, the input voltage is applied between the two base terminals of a unijunction transistor and the output pulse obtained across a capacitor connected between the emitter terminal and one of the base terminals of the transistor. A zener diode is coupled between the emitter and the other base terminal of the transistor.
Inventors
- 👤 Jackson Lum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:45
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/35; H03K3/351
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
244 words
A waveform-shaping circuit comprising: a. input and output terminals; b. a first control element having first, second and third terminals, said first and second terminals being coupled to said input and output terminals respectively, the impedance between the second and third terminals of said first control element being relatively low when the voltage between said second and third terminals exceeds said predetermined percentage of the voltage between said first and third terminals; c. a capacitive element coupled between the second and third terminals of the first control element; d. a second control element having a first terminal coupled to said input terminal and a second terminal; the impedance between the first and second terminals of said second control element being relatively high when said first terminal is positive with respect to said second terminal and of a magnitude which is less than a predetermined value, the impedance between said first and second terminals being relatively low when the magnitude of the voltage thereacross exceeds said predetermined value; and e. a resistive element, said resistive element being coupled between the second terminal of said second control element and the second terminal of said first control element, a pulse being generated between the second and third terminals of said first control element when said predetermined percentage of the voltage between the first and third terminals of said first control element is less than the voltage between said second and third terminAls of said first control element.
Claim 2
Dependent Claim
244 words
A waveform-shaping circuit comprising: a. input and output terminals; b. a first control element having first, second and third terminals, said first and second terminals being coupled to said input and output terminals respectively, the impedance between the second and third terminals of said first control element being relatively low when the voltage between said second and third terminals exceeds said predetermined percentage of the voltage between said first and third terminals; c. a capacitive element coupled between the second and third terminals of the first control element; d. a second control element having a first terminal coupled to said input terminal and a second terminal; the impedance between the first and second terminals of said second control element being relatively high when said first terminal is positive with respect to said second terminal and of a magnitude which is less than a predetermined value, the impedance between said first and second terminals being relatively low when the magnitude of the voltage thereacross exceeds said predetermined value; and e. a resistive element, said resistive element being coupled between the second terminal of said second control element and the second terminal of said first control element, a pulse being generated between the second and third terminals of said first control element when said predetermined percentage of the voltage between the first and third terminals of said first control element is less than the voltage between said second and third terminAls of said first control element.
Claim 3
Dependent Claim
42 words
The waveform-shaping circuit defined by claim 1 wherein said first control element is a unijunction transistor, the first and third terminals of said first control element being the base terminals of said transistor and the second terminal being the emitter terminal thereof.
Claim 4
Dependent Claim
16 words
The waveform-shaping circuit defined by claim 1 wherein said second control element is a zener diode.
Claim 5
Dependent Claim
45 words
The waveform-shaping circuit defined by claim 1 wherein one end of a second resistive element is coupled to the junction of said second control element and said first resistive element and the other end is coupled to the third terminal of said first control element.
Claim 6
Dependent Claim
290 words
A waveform-shaping circuit comprising: a. input and output terminals; b. a unijunction transistor having first and second base terminals and an emitter terminal, said second base and emitter terminals being coupled to said input and output terminals respectively, the impedance between the emitter and first base terminals of said transistor being relatively high when the voltage between said emitter and first base terminals is less than a predetermined percentage of the voltage between said first and second base terminals, and relatively low when the voltage between said emitter and first base terminals exceeds said predetermined percentage of the voltage between said first and second base terminals; c. a capacitor coupled between the emitter and first base terminals of said transistor; d. a zener diode having a first terminal coupled to said input terminal and a second terminal, the impedance between said first and second terminals of said zener diode being relatively high when said first terminal is positive with respect to said second terminal and of a magnitude which is less than a predetermined value, the impedance between said first and second terminals being relatively low when the magnitude of the voltage thereacross exceeds said predetermined value; e. a first resistor, said first resistor being coupled between the second terminal of said zener diode and the emitter terminal of said transistor; and f. a second resistor coupled between the junction of said zener diode and first resistor and the first base of said transistor, a pulse being generated between the emitter and first base terminals of said transistor when said predetermined percentage of the voltage between the first and second base terminals of said transistor is less than the voltage between said emitter and first base terminals of said transistor.
Claim 7
Dependent Claim
290 words
A waveform-shaping circuit comprising: a. input and output terminals; b. a unijunction transistor having first and second base terminals and an emitter terminal, said second base and emitter terminals being coupled to said input and output terminals respectively, the impedance between the emitter and first base terminals of said transistor being relatively high when the voltage between said emitter and first base terminals is less than a predetermined percentage of the voltage between said first and second base terminals, and relatively low when the voltage between said emitter and first base terminals exceeds said predetermined percentage of the voltage between said first and second base terminals; c. a capacitor coupled between the emitter and first base terminals of said transistor; d. a zener diode having a first terminal coupled to said input terminal and a second terminal, the impedance between said first and second terminals of said zener diode being relatively high when said first terminal is positive with respect to said second terminal and of a magnitude which is less than a predetermined value, the impedance between said first and second terminals being relatively low when the magnitude of the voltage thereacross exceeds said predetermined value; e. a first resistor, said first resistor being coupled between the second terminal of said zener diode and the emitter terminal of said transistor; and f. a second resistor coupled between the junction of said zener diode and first resistor and the first base of said transistor, a pulse being generated between the emitter and first base terminals of said transistor when said predetermined percentage of the voltage between the first and second base terminals of said transistor is less than the voltage between said emitter and first base terminals of said transistor.
Claim 8
Dependent Claim
62 words
The waveform-shaping circuit defined by claim 5 wherein the breakdown voltage of said zener diode is greater than the larger of Vm (1 - Mu ) and , where Vm is the maximum voltage applied between the base terminals of said unijunction transistor, Mu is the intrinsic standoff ratio of said transistor and Vsat is the emitter saturation voltage of said transistor.
Claim 9
Dependent Claim
23 words
The waveform-shaping circuit defined by claim 5 wherein a third resistor is coupled in series with the first base terminal of said transistor.
Claim 10
Dependent Claim
18 words
The waveform-shaping circuit defined by claim 5 wherein a fourth resistor is coupled in series with said capacitor.
References Cited (Backward Citations)
US3202937A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |