US3586936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Visual tuning electronic drive circuitry for ultrasonic dental tools
Assignee: C&B Corp
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Filing: 1969-10-16
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Granted: 1971-06-22
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Expires: 1989-10-16
Abstract
Abstract Solid state electronic circuitry for driving the magnetostrictive transducer of ultrasonic dental tools is described, wherein tuning to resonance is controlled by circuit adjustment to maximum brightness of a tuning indicator lamp. Variation of brightness of the lamp as a function of tuning accuracy is achieved by feeding a reference voltage proportional to the excitation current flowing through the ultrasonic transducer to the input of a differential amplifier stage to compare it with a preset reference voltage. The varying output voltage thus derived is amplified to provide an energization current for the indicator lamp which will be proportional to the transducer excitation current and thus an indication of tuning to resonance.
Inventors
- 👤 Robert P Mcleroy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:18
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/0207; B06B1/0223; B06B2201/00; B06B2201/50; B06B2201/58; B06B2201/70; B06B2201/76
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
213 words
Electronic drive circuitry for exciting a magnetostrictive transducer used in ultrasonic dental tools and the like comprising, in combination, a source of DC potential, a solid state ultrasonic oscillator energized by said source of DC potential and providing a substantially sawtooth waveform output signal voltage, a power amplifier energized by said source of DC potential and having an input controlled by said output signal voltage, said power amplifier providing a power output signal, an ultrasonic transducer energized as the load of said power output signal, indicator means responsive to current flowing through said transducer to visually indicate tuning to resonance thereof upon variation of said frequency of said sawtooth waveform output, (Electronic drive circuitry for exciting a magnetostrictive transducer, as defined in claim 1, wherein) said indicator means (comprises) comprising a current-responsive visual indicator and a differential amplifier stage having an input transistor and an output transistor, circuit means responsive to load current flowing through said power amplifier and providing a substantially proportional DC reference voltage, said reference voltage being applied to a controlling element of said input transistor, a predetermined comparison DC voltage applied to a controlling element of said second transistor, and a load resistor for said second transistor providing a variable output voltage for energization of said current-responsive visual indicator.
Claim 2
Dependent Claim
25 words
Electronic drive circuitry for exciting a magnetostrictive transducer, as defined in claim 1, wherein said oscillator is in the form of an RC relaxation circuit.
Claim 3
Dependent Claim
29 words
Electronic drive circuitry for exciting a magnetostrictive transducer, as defined in claim 2, wherein said RC relaxation circuit comprises means for varying the frequency of said sawtooth waveform output.
Claim 4
Dependent Claim
30 words
Electronic drive circuitry for exciting a magnetostrictive transducer, as defined in claim 3, wherein said sawtooth waveform output is variable within the frequency range of between 16.5 and 21 kilocycles.
Claim 5
Dependent Claim
21 words
Electronic drive circuitry for exciting a magnetostrictive transducer, as defined in claim 1, wherein said visual indicator comprises an incandescent lamp.
Claim 6
Dependent Claim
150 words
Electronic drive circuitry for exciting a magnetostrictive transducer used in ultrasonic dental tools and the like comprising, in combination, a source of DC potential, a solid state ultrasonic oscillator energized by said source of DC potential and providing a substantially sawtooth waveform output signal voltage, a transistor power amplifier energized by said source of DC potential and having an input controlled by said output signal voltage, a DC bias circuit including a bias resistor for said power amplifier, said power amplifier providing a power output signal, an ultrasonic transducer energized as the load of said power output signal, and indicator means responsive to current flowing through said bias resistor to visually indicate tuning to resonance of said transducer upon variation of said frequency of said sawtooth waveform output, said bias resistor being operative as a current-limiting resistor with respect to said power amplifier upon accidental short circuiting of said transducer.
Claim 7
Dependent Claim
150 words
Electronic drive circuitry for exciting a magnetostrictive transducer used in ultrasonic dental tools and the like comprising, in combination, a source of DC potential, a solid state ultrasonic oscillator energized by said source of DC potential and providing a substantially sawtooth waveform output signal voltage, a transistor power amplifier energized by said source of DC potential and having an input controlled by said output signal voltage, a DC bias circuit including a bias resistor for said power amplifier, said power amplifier providing a power output signal, an ultrasonic transducer energized as the load of said power output signal, and indicator means responsive to current flowing through said bias resistor to visually indicate tuning to resonance of said transducer upon variation of said frequency of said sawtooth waveform output, said bias resistor being operative as a current-limiting resistor with respect to said power amplifier upon accidental short circuiting of said transducer.
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) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |