Did You Know...
...that Charles Goodyear performed some of his experiments on rubber while in debtor's prison? He was there so often he referred to it as his "hotel". Chronically in debt because of poor business sense and ill health, Goodyear depended on the generosity of friends and family. Even after he unlocked the secret to vulcanizing rubber, he was unable to improve his financial situation. When he died, his estate was $200,000 in debt.
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| Number | Title | Issue Date |
| 7368654 | Anti-resonant transducer The present invention is an device and method for providing an improved transducer for musical instruments. It an object of the present invention to provide a transducer which, because of its design, can be placed on or within a musical instrument quickly and... | 05/06/2008 |
| 7015621 | Piezoelectric actuator device The present invention relates to a piezoelectric actuator device that enables hysteresis of the amount of displacement in the piezoelectric actuator to be reduced, enables the system configuration to be simplified, and for which a high voltage need not be applied. A... | 03/21/2006 |
| 6950640 | FM detector circuit An FM detector circuit includes a bridge circuit having four sections with a discriminator connected as one of the four sections. An FM intermediate frequency is applied across one pair of diagonally opposed nodes of the bridge circuit and an output is picked up acr... | 09/27/2005 |
| 6215830 | Carrier control loop for a receiver of digitally transmitted signals A carrier control loop (1) for a receiver of digitally transmitted signals is disclosed comprising, in the direction of signal flow, a quadrature demodulator (3), a symbol recognition device (4), a detector (9) for forming a phase deviation value ($c;d... | 04/10/2001 |
| 4583047 | Reception circuit for a wave modulated at one time in frequency by an analog signal and at another time in phase by a digital signal The circuit comprises a surface acoustic wave device. On the substrate (32) f the surface acoustic wave device, are provided two pairs of input transducers (33, 34, 35, 36) connected, in parallel, to the input of the circuit. The transducers (33, 34, 35, 3... | 04/15/1986 |
| 4562404 | FM Demodulator with selective phase shift circuits The disclosure is directed to an improved FM demodulating circuit which is simple in circuit construction, with a small number of parts required, and so arranged that in a quadrature detecting circuit, a plurality of piezoelectric resonators, for example,... | 12/31/1985 |
| 4490680 | Integrable quadrature FM demodulator using fewer signal pins A quadrature type FM demodulator device used, for example, in a television receiver, includes a band pass filter for filtering a sound intermediate frequency (SIF) signal input to the device. The output of the band pass filter is coupled through a filter ... | 12/25/1984 |
| 4418320 | High frequency discriminator with a crystal phase shift network A high frequency discriminator is disclosed with a phase shift circuit using a piezoelectric crystal and a series connected load resistor. The voltage across the load resistor is shifted in phase an amount corresponding to the deviation of the input signa... | 11/29/1983 |
| 4305061 | Electrical filter and signal discriminating apparatus employing the same The disclosure relates to an improved signal discriminating apparatus which includes an electrical filter having as a central frequency, a value between the frequencies of two signals different from each other in frequency the presence or absence of each ... | 12/08/1981 |
| 4207535 | Two-pole, fixed-tuned monolithic crystal frequency discriminator A two-pole fixed-tuned monolithic crystal frequency discriminator circuit is provided wherein a tuned circuit is utilized connected between the center pin of the two-pole crystal device and ground. In this manner, two bandpass filters are effectively prov... | 06/10/1980 |
| 4144501 | Quadrature FM detector including low reactance phase shifter An improved quadrature detector for producing a frequency demodulated signal employing a low reactance phase shifter. A quadrature FM detector demodulates a frequency modulated signal by phase comparison of a signal directly from the limiter with a signal... | 03/13/1979 |
| 4006424 | Wide bandwidth crystal frequency discriminator circuit Frequency discriminators are disclosed employing a crystal filter having a predetermined voltage versus frequency characteristic including a discriminator operating portion slightly below the filter lower cutoff frequency along which the voltage varies su... | 02/01/1977 |
| 3987367 | Surface wave discriminator system The invention relates to surface wave discriminator systems comprising a substrate on the surface of which are arranged two electromechanical filters each incorporating two delay lines of dissimilar delay length. The amplitudes of the alternating voltages... | 10/19/1976 |
| 3936764 | Frequency discriminator utilizing surface wave devices A frequency discriminator utilizing a pair of surface wave devices each comprising one transducer on a piezoelectric substrate connected in series with a signal source and a pair of envelope detectors connected in series with the surface wave devices is s... | 02/03/1976 |
| 3936751 | SWD FM detector and IF filter An SWD structure is employed in an FM receiver for signal demodulation and band limiting. An FM signal is applied to the input of an SWD patterned for bandwidth limitation. Two SWD output channels characterized by predetermined differential delays of the ... | 02/03/1976 |
| 3934207 | Frequency discriminator utilizing surface wave devices Frequency discriminators utilizing a pair of surface wave devices each comprising one transducer on a piezoelectric substrate connected in parallel with a signal source and a pair of envelope detectors connected in parallel with the surface wave devices a... | 01/20/1976 |
