To all whom it may concern:
Let it be known that we, the members of BLERK research, operating in Charlottesville, Virginia, have developed improvements on current telephonic communications systems of which the following document will specify.
Prior art in this area includes patents held by Alexander Graham Bell, no.s 174,465 and 186,787 (hereafter Bell's first and second patents respectively), and certain designs presented by the Smithsonian Institution (hereafter referred to as the Smithsonian document) based upon Mr. Bell's designs. These patents and specifications describe a communications system based upon the principle of using air vibrations to induce an undulating electrical current in a transmitter, causing that current to be sent to a receiver and translated back into identical vibrations in the air. Such a system could be used to transmit voices for great distances.
Our system is similar in some ways to those described in the Smithsonian document and Bell's second patent, but we have developed certain components that represent improvements on current systems. Our system has two major components that will be dealt with separately: the transmitter assembly and the receiver assembly. But first, our major improvement is in the manner in which the electric signal is sent from transmitter to receiver; it is encoded in the fluctuations of a high power alternating electrical current. In all current systems, the signal is imbedded in the fluctuations of a direct electric current (based on Bell's first patent). After conducting experiments independent from our research team, Mr. Randy confirmed the ability to convert a direct electric current to an alternating one. The advantage of using an alternating current to send a signal over a long distance is thus: there is a much lesser drop in power (and therefore signal) due to electrical resistance over distance than if a non-alternating current is used. And so our system will be more efficient over long distances than any current telephonic system.
In our transmitter, vibrations of the air will cause the diaphragm to vibrate and make the degree of contact in the circuit of the primary wire of our induction coil to vary, leading to a changing direct current. This causes rapid partial and/or total collapses in the magnetic field of the electromagnet around which the primary wire is coiled. When the magnetic field collapses, an alternating current will be induced in the secondary wire, and this alternating current will vary in amplitude with direct proportion to the degree of field collapse in the electromagnet and in frequency to the frequency with which the field fluctuates. And so the entire signal is preserved, from air vibrations (sound), to the diaphragm, to the varying direct current in the primary wire, to the collapsing magnetic field of the electromagnet, to the variations of the alternating current of the secondary wire.
The first part of the receiver is the transformer; an iron ring transformer is used to boost the signal should there be any loss of power during transmission. As the alternating current passes through the coils around the electromagnet, it causes variations in the magnetic field surrounding the magnet and causes a metal diaphragm in close proximity to vibrate with the changing magnetic field. The vibrating diaphragm then causes the surrounding air to vibrate, producing sounds that correspond to the variations in the alternating current. And so we have a system for the encoding of sounds into an alternating electrical current, the transmission of those signals, and for reproducing the original sounds.
We shall now take the opportunity to describe in detail the apparati that we have designed to perform these functions. We shall be certain to make special note of parts of our design that represent improvements over prior devices. The first device that we will describe is the simpler one: the receiver assembly. Then the transmitter assembly will be described afterwards.
Figure 1 will be the basis for all references for the receiver assembly. Our basic design is based on the Type II magneto receiver in the Smithsonian document. The alternating current from the transmitter comes to the transformer and induces a stronger signal (A). The transformer, one of our improvements, is an iron ring with a small number of coils in the wires coming from the transmitter and a large number of coils in the wires going to the electromagnet. The ratio of coils for the transmitter to the receiver should be at least 1:5. This quintupling of power should more than make up for any loss in transmission. The wires from the transformer are coiled about a U-shaped piece of iron with many turns of small diameter insulated wire from the transformer to insure a strong magnetic field can be formed (B). This choice of a U-shaped piece of metal represents one of our improvements; after a series of experiments with various straight pieces of iron, we discovered the U-bolt. By its shape, it allows for more coils to be made on it than in a straight piece of metal of similar length, and the field of the magnet will be wider than one of a similar piece of straight metal. This wider field will allow larger diaphragms than are in use at this time to be set in motion so as to increase the strength of the sounds produced. The last important feature of the receiver is the Spring Suspended Diaphragm (SSD). The diaphragm (C) is a light piece of metal set in proximity to the electromagnet. When the magnetic field in the electromagnet fluctuates with the varying current, the diaphragm is set in motion. The spring suspension component (D) is an improvement that is intended to offset the weight of the diaphragm and allow it to 'float' in the magnetic field of the electromagnet; the suspension will allow clearer sound production. This system was developed as an attempt to reduce the effect of the diaphragm's weight on its vibrations.
Figure 2 is the basis for all references for the transmitter assembly. The SSD (A and B) is similar to the one described in the receiver. The main difference is that the diaphragm does not need to be made of a magnetically sensitive material. Sounds coming to the transmitter cause the diaphragm to vibrate. There is a small needle that is attached to the diaphragm and leads to the lever (C) so that the motion of the diaphragm is amplified in the second needle (D). The needles and the lever are the Vibration Magnification Assembly (VMA); The multiplication of movement represents an advantage over current designs as it results in an amplified signal. Motion of this needle brings it further into and out of a small container of a low resistance fluid (E). An electric circuit using a series of low power voltage sources is established from the second needle, around the electromagnet (in a small number of coils, called the primary coils), and to the bottom of the container (E). As the needle dips further into the fluid, a larger amount of current flows through the circuit, making the magnetic field in the electromagnet (F) stronger. As the needle moves out of the fluid, the amount of current decreases and the magnetic field collapses. This current changes directly with frequency and amplitude of vibrations in the diaphragm. The collapsing/uncollapsing field of the electromagnet induces an alternating current in the secondary wire wrapped around the electromagnet. This induced current is of a very high power because of the large number of coils of this secondary wire; the ratio of secondary coils to primary coils needs to be at least 10:1. The secondary wire then leads to the receiver (G). The last feature of the transmitter that needs to be addressed is the construction of the electromagnet. We use several small diameter rods bound together and wrapped with the primary wire and then the secondary wire. This is an advantage because the greater amount of surface area of several rods compared to a single large one is that the magnetic field can change more rapidly and thus our transmitter is more responsive to small variations in the signal.
Having described our invention, what we claim, and desire to secure by Letters Patent, is as follows:
- The method of encoding a telephonic signal in an alternating electric current.
- The method of setting a diaphragm into vibration through induction in a permanent magnet caused by a signal in an alternating electric current.
- The method of setting a diaphragm m into vibration through induction in an electromagnet.
- The practice amplification a diaphragm vibrations through a construction of levers and armatures.
- The method of reducing the effective weight of a diaphragm will vibrate at more levels.
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