Patent Publication Number: US-9905065-B2

Title: Radio controls for electric devices and methods for transmitting commands through radio controls

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority under 35 U.S.C. § 119 from Italian Patent Application No. MI 2015 A 000359, filed on Mar. 10, 2015, in the Italian Patent and Trademark Office, the entire contents of which are incorporated herein by reference. 
     The present invention refers to a radio control for electric devices. 
     In particular, the present invention refers to a radio for electric devices, like for example gates, doors, main doors and barriers in general. 
     Radio controls are typically used in automatic gates, which originally were actuated only with mechanical controls like buttons or key switches. 
     In over twenty years, the technology used for this type of products has evolved substantially, both in terms of the radio frequency part and for the encoding systems adopted. The first radio control systems worked at low frequency, over a range that extended from 27 to 41 MHz: they were therefore radio controls often of considerable size due to the antennae made of ferrite and the batteries used. 
     Over time they were then replaced by systems called “free frequency” operating at high frequency and in a band normally comprised between 260 and 350 MHz. This new category, longer needing to comprise bulky antennae and substantial power supply, gave rise to families of pocket-sized products. Thereafter, European standards regulated and set the frequencies that can be used for automation. There are currently four frequencies in use: two at low frequency (40.665 MHz and 40.685 MHz) and two at high frequency (433.92 MHz and 868.35 MHz). 
     The other aspect, the most important one of a radio control, is its encoding. This term means the information trnasmitted (code) on the carrier (frequency) to make it reach another different point from where it started. The first radio controls used a fixed code encoding, i.e. information that was always the same and never changed and this code was set by a component located on the transmitter—the so-called “dip-switch”, formed from a series of small switches arranged in a row. 
     Thereafter, this component was eliminated to reduce the size of the radio control, and therefore if before it was simple to set a personal code, today it is less so, since most manufacturers set it in the factory and it can no longer be modified by the user, of course with a few exceptions. 
     Recently, this encoding has been added to by another, with a dynamic code or variable code. 
     This encoding technique was wanted to make the use of these products more secure with respect to fixed code, but also to make it difficult to copy the original radio control, thus restricting the spread of compatible products. The operating principle of the dynamic code is that of always transmitting a different code from the previous one upon each activation of the transmitter, of course the new code also changes in the receiver, which ensures that the two products are always synchronised. 
     The objective in actual radio controls is to increase as much as possible the reliability in the execution of the controls imparted and security, in the attempt to prevent them from being cloned. 
     The present invention refers to a radio control of this type in which security and reliability are both improved with respect to radio controls of the known art. 
     An aspect of the present invention relates to a radio control for electric devices having the features of the attached claim  1 . 
     A further aspect of the present invention relates to a method for transmitting a control to an electric, device through a radio control having the features of the attached claim  9 . 
    
    
     
       The features and advantages of the radio control according to the present invention will become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings, in which: 
         FIG. 1  is a perspective view of a radio control with two buttons according to the present invention; 
         FIG. 2  is a block diagram of the electronic circuits present inside the transmitter according to the present invention; 
         FIG. 3  is a flow algorithm of the operation of the radio control according to the present invention. 
     
    
    
     With reference to the mentioned figures, the radio control according to the present invention comprises a containment body, for example box-shaped  2 , inside which an electronic board is inserted, the functionalities of which are activated through at least one button  3  provided on such a box-shaped body. 
     The block diagram of such an electronic board is illustrated schematically in  FIG. 2  illustrating a microprocessor  4  that receives the signals of such buttons  3  and that generated by an encoder  41 , advantageously of the variable code type. Alternatively, instead of the variable code encoder a “dip switch” can be inserted that is formed from a plurality of switches encapsulated in a single container, equipped with terminals arranged over two rows at normalised distance. The switches are preferably switches with two positions and alternatively with more than two positions. By acting on each of such switches it is possible to generate a unique frame or key that can be predetermined and modified according to the type of use that is wished to be obtained of the radio control. 
     The electronic board also comprises at least one receiver  51 , and a transmitter  52  connected to such a controller  4  and electrical power supply means  6  that provide the power supply necessary for all of the components of the electronic board. Such power supply means preferably comprise a single 3V battery (CR2032). Moreover, on such a board there are suitable amplifying, filtering and frequency modulation means  53  of the signals received by such a receiver and for the signals to be sent to said transmitter. 
     Moreover, the radio control is provided with at least one suitable luminous signalling device (for example with LEDs) controlled by the microprocessor. 
     The radio control operates in the following way. 
     With reference to the algorithm of  FIG. 3 , the radio control is in the stable “stand by” condition, i.e. in which there is the minimum consumption of the power supply battery  6 . 
     When one of the buttons  3  is pressed, the radio control comes out of the standby mode and determines a code to be transmitted through the encoder  41 , preferably a code determined by a variable code encoding. 
     Such a code is transmitted through the mentioned transmitter at least once at a first frequency (for example 433.92 MHz) and then retransmitted at least once at a second frequency (for example 868.35 MHz). 
     Once the two transmissions have ended, the correct transmission of the code is signalled, for example through the help of such LEDs. 
     Advantageously, each time the button is pressed such a code is transmitted a predetermined number of times alternately over the two frequencies up to the maximum number NMAX. 
     The device will continue to transmit until the button previously pressed is released. 
     Preferably, before each code transmission a battery control procedure monitors the level of the battery  6  itself of the radio control. In the case of a low battery level the radio control emits a signal, for example luminous (e.g. intermittent flashing) before signalling that the transmission has been carried out.