| 序号 | 专利名 | 申请号 | 申请日 | 公开（公告）号 | 公开（公告）日 | 发明人 |
|---|---|---|---|---|---|---|
| 141 | Signal processing system | US71098 | 1979-08-31 | US4289140A | 1981-09-15 | David A. Carpenter; George Kossoff; George D. Radovanovich |
| Echoscopes incorporating signal processing circuits capable of providing a more complete and useful display of information received as a train of electrical signals. In one circuit, which is essentially a compression amplifier, the amplitude range of the input signal is limited by way of two or three amplitude limiting stages and an adder connected to sum the output of the first and last stages provides an advantageous output to input characteristic for the circuit.The second circuit includes filter means and derivating means to separately process the input signal, and an adder to combine the outputs of these means to obtain a signal of enhanced utility. | ||||||
| 142 | Headset with limiter circuit | US15359 | 1979-02-26 | US4224470A | 1980-09-23 | Leif A. T. Persson; Tord P. Lundin |
| Each of a pair of ear pads is provided with an electrically-operated earphone. The earphones are connected to each other by a circuit having a cord for connecting the earphones to an external audio-signal source. The circuit includes a pair of Zener diodes connected in back-to-back or opposed parallel relation to each other, and in parallel to the earphones so that if an incoming AC audio signal exceeds a predetermined value one of the diodes will fire to short the input signal, thus limiting the output (in decibels) of the earphones. A field-effect transistor is connected in series with the earphones to limit the current load thereto. | ||||||
| 143 | Circuit arrangement for optional dynamic compression or expansion | US931394 | 1978-08-04 | US4218662A | 1980-08-19 | Ernst Schroder |
| A circuit arrangement for automatic dynamic compression and/or expansion having an auxiliary circuit provided in the useful signal path or in the negative feedback path of an amplifier. The auxiliary circuit has a first and a second connection point. On the one hand there are arranged between the first and the second connection point a first damping or amplifying member, an electronically controllable damping member and a second damping or amplifying member connected in series. On the other hand means for limiting the voltage or current are arranged between the first and second connection point. | ||||||
| 144 | Current limiter | US917230 | 1978-06-20 | US4217503A | 1980-08-12 | Philippe Hugel; Henri Kraess; Remi Louis; Louis Vidonne |
| A current limiter such as a thermistor has a slow response time and inserts appreciable loss to normal signal currents that do not need limiting. The present invention uses a diode quad (6,7,8 and 9) arranged in a full-wave rectifier configuration. The AC terminals of the quad are inserted in series in the circuit whose current is to be limited. The DC terminals are connected to receive a DC bias current from a constant current source (P, R1). A signal from a signal generator (1) flows through a load (2) substantially unhindered by the current limiter until its instantaneous valve reaches that of the bias current I, in which case the signal current is clipped regardless of the direction of its current flow because the signal current cancels the bias current flowing through two of the diodes thereby reverse biasing them and effectively switching the current through the constant current generator. For practical telephone applications it suffices if the resistance (R1) of the bias source is at least ten times that of the load (2). | ||||||
| 145 | Magnetic recording system with reduction of high frequency signal distortion in vicinity of saturation level | US32194473 | 1973-01-08 | US3873992A | 1975-03-25 | SATO FUJIO; FUJIMOTO EISUKE; SATO KEISUKE; TANAKA BUNICHIRO |
| The amplitude of high level high frequency components of a signal to be recorded on a magnetic recording medium is suppressed in the vicinity of a saturation level of the magnetic recording medium prior to its recording in order to obviate high frequency distortion due to magnetic losses. High fidelity recording of a high level signal containing high frequency components is enabled with little distortion and improved signalto-noise ratio.
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| 146 | Operational amplifier clamping | US33397673 | 1973-02-20 | US3822408A | 1974-07-02 | VERANTH J |
| In an amplifier having a number of stages with feedback from the output to the input, the input stage is clamped at a level slightly beyond the point where the output level is clipped independent of the clipping level or extent of phase shift in the output stage to reduce the time for overload recovery.
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| 147 | Signal limiter for exalted carrier am detector | US3796963D | 1972-11-06 | US3796963A | 1974-03-12 | BALABAN A |
| A signal limiter operable at video i-f frequency with substantially less AM to PM conversion than prior art signal limiters includes a pair of diodes in inverse parallel combination (with the anode of one diode connected to the anode of the other) between the emitter electrodes of first and second common-collector transistors. Anti-phase i-f signals are applied respectively to the first transistor and second transistor base electrodes. The transistors alternately function as emitter followers to provide a low impedance (of the order of diode forward-impedance) drive to the diode combination to maintain limiter frequency response despite stray capacitances. While one of the transistors functions as an emitter follower, the other has its base-emitter junction reverse-biased, permitting the quiescent current demands of the limiter to be lower than where emitter-follower action is constantly maintained in both transistor circuits. The signal limiter output signal is extracted by differential amplifier means having inverting and non-inverting input terminals connected at respective ends of the diode combination. The differential amplifier may be arranged to be a product detector in an exalted carrier video detector.
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| 148 | Logarithmic amplifier | US3646456D | 1970-07-09 | US3646456A | 1972-02-29 | KAUFFMAN EUGENE C; LOCKWOOD LARRY R |
| A nonlinear amplifier circuit is described which may be used to provide a logarithmic amplifier. The amplifier circuit includes a plurality of similar stages connected in cascade, each stage including an operational amplifier and a limiter circuit connected in parallel with a portion of the input coupling resistance of such operational amplifier. The limit circuit is current-mode actuated and includes a pair of diodes connected in series opposition which are switched from a quiescent lowimpedance state to a high-impedance state when the signal current exceeds a predetermined level. This causes an increase in the effective input coupling resistance and thereby reduces the gain Zf/Zin of the operational amplifier stage to unity. As a result of cascade amplification, five amplifier stages are switched to unity gain in successive order from the output to the input of the amplifier circuit, thereby forming each of the segments of the logarithmic output.
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| 149 | Noise reduction system | US3628061D | 1969-12-17 | US3628061A | 1971-12-14 | JACKMAN ROBERT W |
| A system for reducing noise in an electrical signal. Diodes provide for limiting the incremental magnitude of output voltage change relative to a previous output voltage level. With diode bias, the permitted change is controlled by feedback from the system output and by externally applied control voltages. A digital ramp voltage generator is presented incorporating such a system for eliminating noise spikes resulting from noncoincident operation of flip-flops.
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| 150 | Overload compensation for antenna-tuning system | US3571715D | 1968-12-16 | US3571715A | 1971-03-23 | BEARY GENE; HEAGNEY ANTHONY T; NILSSEN OLE K |
| A tank circuit for tuning the antenna of a radio receiver includes a voltage variable diode capacitor as the variable tuning element therein. In order to prevent strong RF input signals from appearing across and being rectified by the voltage variable capacitor, an attenuating circuit in the form of a shunt resistor or a capacitive voltage divider is connected across the antenna input to the tank circuit whenever the level of the RF signal exceeds a predetermined amount. This connection of the attenuating circuit across the antenna may be effected directly in response to the RF signal level itself or in response to a switch operated by the AGC signal of the receiver of which the antenna-tuning circuit is a part.
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| 151 | Adjustable amplitude limiter circuit | US3437837D | 1965-11-19 | US3437837A | 1969-04-08 | HULL ROBERT E |
| 152 | Amplifier employing nonlinear dc negative feedback to stabilize its dc operating point | US3432763D | 1966-12-13 | US3432763A | 1969-03-11 | INGMAN ERIC M |
| 153 | Data transmission apparatus utilizing frequency shift keying | US3432616D | 1965-04-15 | US3432616A | 1969-03-11 | CROUSE WILLIAM G |
| 154 | Low level signal limiter | US58221366 | 1966-09-22 | US3404348A | 1968-10-01 | HANSEN IRVING G; PETERSON VICTOR S |
| 155 | Tunnel diode amplitude limiter circuit | US34668964 | 1964-02-24 | US3344354A | 1967-09-26 | EDWARD BELLEM |
| 156 | Sinusoidal to rectangular wave converter and amplifier | US35181264 | 1964-03-13 | US3299293A | 1967-01-17 | GEORGES KNAPP-ZILLER MICHEL ED |
| 157 | Device for drying hair and fingernails | US28936363 | 1963-06-20 | US3272966A | 1966-09-13 | SUTTON EARL E |
| 158 | Device for use in telephone sets | US11946061 | 1961-06-26 | US3177294A | 1965-04-06 | JAN SCHALKWIJK |
| 159 | Linear amplifier with a non-linear feed-back network | US20478862 | 1962-06-25 | US3166720A | 1965-01-19 | ROSEN FRANK L; FLOOD JOHN F |
| 160 | Variable limiter for analog computer using a fixed zener diode | US8823461 | 1961-02-09 | US3153152A | 1964-10-13 | HOFFMAN JR HENRY C |
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