Did You Know...
...that several people are credited with the invention of the flush toilet? Most people have heard of Thomas Crapper (1837-1910), the sanitary engineer who invented the valve-and-siphon arrangement that made the modern toilet possible. Another claimant to "the throne" was British inventor Alexander Cumming who patented a toilet in 1775. Then there's a nameless Minoan (a native of ancient Crete) who lived 4,000 years ago who supposedly was ahead of his time and created the first flush toilet!
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| Number | Title | Issue Date |
| 4379269 | RF Amplifier having automatic gate bias switching in response to band selection Herein disclosed is an RF amplifier which is equipped with a high-frequency amplifying element such as a dual gate MOS FET having its first gate fed with a bias voltage and its second gate fed with an AGC voltage, in which a switching diode is fed with a ... | 04/05/1983 |
| 4377788 | Signal expander The envelope of an input signal to be expanded is detected and applied via an adaptive filter to the gain control input of a variable gain device which expands the input signal. The adaptive filter provides improved ripple reduction and transient response... | 03/22/1983 |
| 4376267 | Video preamplifier for laser systems An automatic gain controlled preamplifier for use with a laser detector and having a wide bandwidth and a low-noise figure. The preamplifier includes a voltage controlled input attenuator stage feeding a low noise wideband amplifier stage which drives an ... | 03/08/1983 |
| 4371846 | Bandwidth control circuitry for radar i-f amplifier A unidirectional current with i-f variations superimposed thereon is applied to the interconnected emitters of a pair of transistors, the collectors of which are coupled to a succeeding stage by a narrow-band filter and by a wide-band filter respectively.... | 02/01/1983 |
| 4366449 | Integrated voltage control variable gain circuit and a signal transmission circuit using the same An integrated voltage control variable gain circuit capable of exhibiting, when the external circuit network is connected in a first configuration, a low distortion factor of the output signal, and capable of effecting, when the external circuit network i... | 12/28/1982 |
| 4365208 | Gain-controlled amplifier using a controllable alternating-current resistance A gain-controlled amplifier is provided which employs a controllable alternating-current resistance device. The device is constructed in a similar manner as a vertical PNP transistor, having an emitter region of high conductivity P+ material, a P type col... | 12/21/1982 |
| 4361816 | Current mirror amplifiers with programmable gain A current mirror amplifier includes first and second transistors connected together at their common electrodes, the first transistor being connected for receiving input signal current at its output electrode, and the control electrodes of the transistors ... | 11/30/1982 |
| 4361815 | Operational amplifier with programmable gain An operational amplifier includes a differential-input amplifier stage supplying first and second drive currents responsive to input signals applied to its input connections. A first current amplifier exhibiting gain factor G supplies currents to an outpu... | 11/30/1982 |
| 4340866 | Thermally-compensated variable gain differential amplifier A linear wideband differential amplifier includes a variable gain stage comprising two cross-coupled differential amplifiers and differential current source to compensate for thermal distortion, to minimize transient response distortion, and to eliminate ... | 07/20/1982 |
| 4335361 | Variable gain amplifier A communications channel monitoring system is disclosed for digitally based communication channels carrying signals corrupted by noise. The monitor system provides a signal indicative of the expected value of the communication channel signal if uncorrupte... | 06/15/1982 |
| 4331931 | Gain control systems Amplification means responsive to an input signal of a gain control circuit is utilized in each log-antilog transmission path of the gain control circuit so as to provide in each path signal gain as a function of said input signal.... | 05/25/1982 |
| 4327333 | AGC Current source A circuit for supplying a pair of currents that vary in opposite directions as a function of a control current. The pair of currents are coupled to an amplifying stage in which the gain varies in accordance with the relative magnitude of the currents. The... | 04/27/1982 |
| 4322811 | Clamping circuit for an adaptive filter In an adaptive filter having a delay cicuit wherein amplitude control circuits are comprised in taps of that delay circuit, which control circuits are controlled by means of an error signal which indicates the difference between an output signal of the fi... | 03/30/1982 |
| 4305044 | Amplifier circuit having controllable gain An amplifier circuit, having voltage gain responsive to a control signal, includes a transistor stage having a transistor and a load, and an amplifier stage in cascade connection, and a control transistor connected to the transistor. The control signal va... | 12/08/1981 |
| 4278945 | Circuit for the generation of a control variable for the control of the transfer constant of electronically actuable amplifying and attenuating members In a circuit for automatic dynamic compression or expansion the control voltage generator generates a control voltage which is linear against the logarithm of the input amplitude. This characteristic is achieved by a transfer member consisting of several ... | 07/14/1981 |
| 4267518 | Gain controllable amplifier stage A common-emitter amplifier having its dynamic voltage gain controlled by using a controlled emitter-follower to shunt the emitter impedance of the common emitter amplifier.... | 05/12/1981 |
| 4242643 | Variable gain current amplifier A current amplifier is disclosed, the current gain of which varies directly with changes in input current. A first transistor, arranged as a slave mirroring transistor provides output signal current responsive to a multi-mode transistor master mirroring c... | 12/30/1980 |
| 4216435 | Voltage-to-current converter apparatus The voltage-to-current converter includes first and second transistors having their respective common electrodes arranged to receive between them the voltage to be converted to current. Their output electrodes have connections to first and second current ... | 08/05/1980 |
| 4168472 | Variable gain controller A variable gain controller comprising an amplifier having a feed back terminal which is connected to a variable resistor including a current controller for controlling current flowing through the variable resistor, a filter connected to the variable resis... | 09/18/1979 |
| 4162457 | Expansion circuit for improved stereo and apparent monaural image An expander circuit for expanding stereo signals comprises left and right channel variable gain stages whose gain varies in proportion to the amplitude of the control signals fed to the control inputs thereof; and left and right channel expansion control ... | 07/24/1979 |
| 4152667 | Gain-controlled signal amplifier In a multi-stage amplifier with delayed AGC-control gain control in one stage is effected by means of controllable current distribution between control transistors. The take-over point of the delayed AGC for a previous stage is determined from the ratio b... | 05/01/1979 |
| 4103246 | Switchable current amplifier A switchable current amplifier comprising first and second transistors of complementary conductivity type, an input terminal connected to the emitter electrode of the first transistor, an output terminal to which the collector electrode of the second tran... | 07/25/1978 |
| 4077014 | Automatic gain control circuit An automatic gain control circuit employs a field effect transistor having a pair of gate electrodes. Distortion factor is minimized by applying a rectified and smoothed output signal to the first gate electrode and applying an input signal to the second ... | 02/28/1978 |
| 4070633 | Remote controlled amplifier An electronic circuit for amplifying a plurality of signals and providing balance between individual signals of the plurality of signals is provided. A first amplifier has at least a first and a second output and is responsive to a balance input so that b... | 01/24/1978 |
| 4065723 | Tuned radio frequency amplifier with back to back varactor diodes connected through a common cathode lead A tuned radio frequency amplifier includes signal amplification means having an input and an output and first and second pairs of varactor diodes, each pair having an inductor connected across the anodes and a common tuning voltage supplied to the common ... | 12/27/1977 |
| 4056791 | Apparatus for correcting distortion in low frequency cable Apparatus for correcting attenuation distortion in low frequency cable carrying a base-band signal from a transmitter to a receiver is described. A measuring device produces an indicating signal having a value dependent on the peak value of the base-band ... | 11/01/1977 |
| 4054844 | Amplifying system An amplifying system comprises an amplifier having a certain constant gain, a first variable attenuator through which an input signal for this system is inputted to the amplifier, and a second variable attenuator through which the output signal of the amp... | 10/18/1977 |
| 4054849 | Signal compression/expansion apparatus Signal expansion/compression apparatus wherein an input signal is compressed by an exponential factor and then subsequently may be expanded by the reciprocal of that exponential factor, wherein neither the signal compression circuits nor the signal expans... | 10/18/1977 |
| 4051442 | Gain control circuits for audio amplifiers A gain control circuit is connected between an output terminal of a transistor detector circuit for audio-frequency or voice signal and an audio amplifier circuit. The gain control circuit comprises a control transistor having an output electrode at which... | 09/27/1977 |
| 4051441 | Transistor amplifiers The collector currents of first and second junction transistors which have base electrodes biased at the same quiescent potential and have emitter electrodes connected via respective emitter degeneration resistances to a common point, are adjusted relativ... | 09/27/1977 |
| 4032854 | Amplification and gain control circuit An amplification and gain control circuit is disclosed in which there is provided in the output circuit of an amplification circuit receiving a gain control input, a semiconductor junction capacitance whose capacity is increased when the amplification cir... | 06/28/1977 |
| 4027281 | Digital recording of sonic log wavetrains The analog signals provided by a seismic-velocity well logger, resulting from the transmission of seismic impulses from a transmitter to a receiver in a logging sonde in a well by paths that include travel through the rock walls of the borehole, are digit... | 05/31/1977 |
| 4001708 | Code-controlled ringer attachment for telephones including a-peak-to-peak gain controlled amplifier A system for selectively deactivating a telephone bell on a telephone instrument whereby when a telephone number is called, an auxiliary system automatically cuts in to prevent ringing of the bell until a predetermined code is dialed or touch-toned, at wh... | 01/04/1977 |
| 4001731 | Device for optionally realizing two mutually complementary functions A switchable compression-expansion device, in which a first and a second impedance are included in the emitter circuits of two emitter followers. The impedances are also included in two isolated signal circuits which are coupled via a current mirror circu... | 01/04/1977 |
| 3988694 | Automatic level controller An automatic level controller comprising a switching transistor connected to the output stage of an audio amplifying circuit to be turned off when the output signal of the audio amplifying circuit attains a predetermined level, a control transistor connec... | 10/26/1976 |
| 3986049 | Audio compressor/limiter amplifier An audio compressor amplifier including an operational amplifier with compressor means connected from the output to the input for compressing signals at the output to a predetermined constant level in a predetermined attack time and including a plurality ... | 10/12/1976 |
| 3984783 | Amplifier An amplifying circuit capable of providing the gain and linearity of Class A amplifier and power conversion efficiency of a Class B or C amplifier is provided. The circuit includes an amplifying device, such as a power transistor, and a biasing network th... | 10/05/1976 |
| 3980964 | Noise reduction circuit A noise reduction circuit for uncompressed and randomly compressed audio signals comprises a variable gain stage providing a gain which varies with the magnitude of a DC control signal fed to a control terminal thereby, an AC to DC converter for generatin... | 09/14/1976 |
| 3955148 | Sampling circuit A sampling circuit is provided which includes a fourterminal semiconductor device of the type having a low emitter doping concentration. The signal to be sampled is fed continuously through the semiconductor device to an output terminal. A gating pulse ap... | 05/04/1976 |
| 3944943 | Broadband amplifier A broadband amplifier with a negative feedback circuit having a variable resistance means and first and second parallel resistor-inductor combinations for slope control is shown. The variable resistance means establishes the overall frequency response and... | 03/16/1976 |
