 VHF tuner |
| In order to eliminate the above-mentioned diasdvantages of the prior art, an object of the present ... |
|
| Spin echo matched filter ECM detector |
| Having described what is at present considered to be the preferred embodiment of the subject ... |
|
| Automatic channel selection apparatus |
| What is claimed is 1. An automatic channel selection apparatus comprising: an electronic tuner ... |
|
| Compact solid state station protector device |
| The present invention involved a compact solid state protector unit which protects the electronic ... |
|
| Guided artillery projectile and method |
| According to the present invention, an artillery projectile is provided. This artillery projectile ... |
|
| Sonotube compatible unmanned aerial vehicle and system |
| The present invention is generally comprised of a sonotube-compatible, micro-miniature, unmanned ... |
|
| Self-destructing impact fuse |
| The present invention includes a cylindrical firing pin having a hollow centrifugal chamber for ... |
|
| Lock-on-after launch missile guidance system using three dimensional scene reconstruction |
| In accordance with the present invention, rather than using a two dimensional description of the ... |
|
| GPS receiver with extended security |
| OF THE PREFERRED EMBODIMENT(S) FIG. 1 is an overview illustration of the operation of secure GPS ... |
|
| Burst height compensation |
| It is an object of the present invention to increase the predictable effectiveness of the reentry ... |
|
|
Proximity switch having variable gain oscillator
| Details |
Inventors: Kamiya, Fumio; Nodera, Hisatoshi; Ueda, Kenji; Imazu, Keinosuke; Tomioka, Hidehiro;
Assignee: Omron Tateisi Electronics, Co. (Kyoto, JP)
Primary Examiner: Grimm; Siegfried H.
Assistant Examiner:
Attorney, Agent or Firm: Wegner & Bretschneider
Disclosed is a proximity switch which includes an oscillation circuit whose oscillation output is variable depending on the inductance of a coil so that an object in proximity may be detected from the decline in the oscillation output. Further, the oscillation gain of this oscillation circuit is variable according to an input from an external source. Thus, for the purpose of increasing the recovery speed of the oscillation which has dropped as a result of detecting an approaching object, comparison circuits are provided so that upon reduction in the oscillation output of the oscillation circuit a certain signal is applied to the oscillation circuit to increase its oscillation gain. As a result, even when an object in proximity is detected and the oscillation level is maintained at a certain low level so that the oscillation may be resumed quickly when the object has moved away from the proximity switch. By virtue of the increased response speed of the proximity switch, not only its detection capability is improved but also it is usable in an environment where a strong AC magnetic field is present. |
|
DETAILED DESCRIPTION In view of such problems of conventional proximity switches, a primary object of this invention is to provide a proximity switch which has a high response speed through speed up in the start of the oscillation of an oscillation circuit A second object of this invention is to provide a proximity switch which is capable of withstanding a strong magnetic field so that it may be used in an environment where a strong AC magnetic field is present.
According to a certain aspect of this invention, there is provided a proximity switch of high frequency oscillation type having an oscillation circuit and a detector circuit which detects an object from reduction in oscillation output, characterized in that: the oscillation circuit is an oscillation circuit which increases its oscillation gain according to an output from an external source; the proximity switch further comprising: a first rectifying circuit which rectifies the output of the oscillation circuit and smoothes the output according to a certain time constant; a second rectifying circuit which rectifies the output of the oscillation circuit and smoothes the output according to a time constant smaller than the mentioned time constant to give an oscillation gain control signal to the oscillation circuit; and a comparison circuit which detects the reduction in the output of the first rectifying circuit by comparing the output thereof with a certain reference level and produces an object detection signal; whereby the oscillation circuit being capable of increasing its gain according to the reduction in the oscillation gain.
According to this aspect of the present invention which is thus characterized, the output of the oscillation circuit is divided between two circuit blocks for signal detection and gain adjustment when the oscillation level has declined to a certain level and, by providing a separate rectifying circuit to each of these circuit blocks, an object detection signal is obtained at different discharge time constants at the same time as adjusting the gains
|
| Related patents |
|
|
Method for sending message that indicates position and message transmission device and message transmission server
1. A method for sending a message that indicates position comprising: a) receiving a first message, said first message including a determination of position and an ...
|
|
|
Phase coherent interference signal suppression system and method
The present invention is an interference signal suppression system which comprises a first and second receiving antenna positioned to receive a communication signal and ...
|
|
|
Bit allocation among carriers in multicarrier communications
Accordingly, the present invention provides a technique that may be employed in multicarrier communications to improve the efficiency of error correction using symbol-...
|
|
|
Interference mitigation system for protecting radio astronomy and method of using same
What is claimed is: 1. A method of mitigating electromagnetic interference during a scheduled radio astronomy session as scheduled at a radio astronomy site, said ...
|
|
|
System and method for recovering a pilot tone in a local multipoint distribution system signal
From the foregoing, it may be appreciated that a need has arisen for an effective and efficient pilot tone recovery system. In accordance with the present invention, an ...
|
|
|
Wireless selective call receiver with alarm message signal stored to have protection attribute
The present invention is made in the light of the above-mentioned circumstances. An object of the present invention is to provide a method for protecting an important ...
|
|
|
Dot printer and method for grey level recording with different bit-depth dimensions
We claim: 1. A non-impact recording apparatus for recording grey level exposures of pixels with different bit-depth dimension, the recording apparatus comprising: a ...
|
|
|
Apparatus with frame check capability for reproducing images by combining outputs of concurrently operating disk players storing portions of the images
It is, therefore, an object of the invention to provide an image reproducing apparatus which can prevent the display of a disordered image due to mismatching of the ...
|
|
|
Digital detector
According to the present invention there is provided a digital detector to convert an audio frequency signal into a digital signal, characterized in that the detector ...
|
|
|
Method and apparatus for improving video scrambling and employing split sync pulses
FIGS. 2A, 2B and 2C illustrate waveforms which illustrate one aspect of the present invention. According to a novel aspect of the present invention, the sync pulse is ...
|
|
|
Telecommunications 
