1. Field of the Invention
The field of this invention lies within the switch art, and the art related to electrically sensing mechanical movement through electrical outputs related thereto.
2. The Prior Art
The prior art relating to switches incorporates limited touch type non-mechanical or solid state switches, toggle switches, and microswitches. In most cases, switching is performed by limiting or ceasing the flow of current through a mechanical contact. However, in some touch type switches switching is performed without the use of mechanical contacts. It is well known to ionize a gas and create conduction therethrough to provide a signal or means for allowing the total conduction of the required signal. For example, neon gas tubes are provided with a voltage level whereby the gas will not conduct until the gas ionizes. At this point, a signal passes thereby creating a switching function.
Other solid state switches incorporate photoelectric means for purposes of activating a light detection means to create a situation whereby a switching function will occur. Still other solid state switches employ an interruption or conduction of light by means of optical means which then create a signal which is used to cause a switching function to take place.
In the above solid state switches, complex movements and actuations must take place before a signal emanates for switching purposes. It is this movement which often causes such signals to be inaccurate and not perform the function of switching to the desired mode. Furthermore, the aggregation of elements necessary to create prior art solid state switches is complex and detailed, thus making them extremely expensive. The expense is oftentimes increased by the fact that various electron tubes and other active and passive components must be provided which do not have anything specifically to do with the switching function but are only utilized to register a signal.
As can be appreciated, solid state switching is extremely useful to prevent contact chattering and unwanted line spikes. This invention provides a solid state switch which is less expensive than prior art switches and provides superior results.
Prior art transducers oftentimes produce an electrical signal analogous to certain mechanical movements so that a signal is created to show an on or off mode, a proportionate movement, an analog movement, or a linear movement. Such transducers do not provide a great degree of linearity and are not in an inexpensive form required in many applications. As a consequence, the use of transducers is limited and when required oftentimes creates a difficult design problem with substantial expense.
This invention provides a transducer having excellent linearity which can be used in numerous applications and is relatively cheap.
The switch and transducer of this invention utilize a fast rising signal preferably having the slope of a step function emanating from a signal source such as a clock. The signal source causes a transistor to turn on or off depending upon the degree of capacitance in the capacitance sensing means. The device incorporates a circuit wherein a switching or transduction of a certain mechanical movement can be easily registered and an analogous signal with respect thereto provided. The switch of this invention is of a highly reliable form and overcomes many of the switching problems associated with the prior art. In addition thereto, the switch can perform in a cheaper and more adaptable manner thereby replacing current state of the art microswitches, switches utilized for analog functions, keyboards for electronic equipment, as well as general computerized switching functions.
As a transducer this invention provides a highly linear output. Furthermore, the transducer can be configured to meet various needs such as the measurement of liquid levels, the movement of precision apparatus and many other needs where certain mechanical movements must be converted to electrical outputs.
The prior art shows that the signal can be changed by means of amplitude. However, in most cases, they need a threshold detector. Applicant's invention substantially provides a signal having its full amplitude.
In effect, the applicant's invention is actually a large phase modulator. The applicant's invention which is a phase modulator, or frequency modulator, has the advantage in that it utilizes a single pulse technique. It saves substantial power, and the limitations with regard to the total energy of the system is lower. Furthermore, applicant's invention is universal with respect to current digital techniques, and works under most conditions therein.