Patent Publication Number: US-6700225-B1

Title: Digital electronic switching systems

Description:
FIELD OF THE INVENTION 
     The invention resides in the field of controlling relatively high voltage circuitry by means of low voltage circuitry. 
     SUMMARY OF THE INVENTION 
     The system and apparatus of the invention have particular adaptability to controlling electrical circuits in the home. A main electrical circuit, or load circuit, of for example 120 V, carries an electrical light bulb as a load. The apparatus includes a control circuit involving low voltage, for example 5 V, which includes light gage wire or conductors, such as what is generally known as bell wire commonly used in connection with doorbells. 
     A principal object of the invention is to provide a high factor of safety. In utilizing such low voltage circuitry, the voltage involved, i.e., 5 V, is not dangerous, and a person may make alterations or changes without taking any extra precautions for safety. 
     The apparatus can be readily adapted to the ordinary wiring arrangement already existing in a home, or it can be utilized in its entirety, initially in constructing a house. 
     Another and specific advantage is that a multitude of switches can be provided in the control circuit, and any one switch alone can be actuated for controlling the main high voltage circuit. 
     By reason of the immediately preceding feature, the number of switches in the low voltage circuit can be changed, i.e. from a small number to a larger number, substantially without changing the circuit, the only requirement being the adding of an extra switch and related conductors to the switches that are already in place. Because of this feature, if a load, such as a light bulb, is already in place, in a room, and more access entries to the room are desired, individual control switches may be added to the control circuit in a simple manner, to accomodate all the added entries to the room, there being no requirement for altering the load circuit. 
     Still another advantage is that the apparatus of the invention can be easily and readily put in a compact unit or package and easily put in an outlet box that was previously provided without the necessity for removing such an old outlet box with corresponding changes in the load circuit. 
     Another feature of the invention is the provision of an overcenter switch to be used in the control circuit that in its actuation from one extreme position to the opposite extreme position, a single pulse is produced only momentarily, so as to produce a controlling signal in a pulsing targeting switch, such as HI to LO, or LO to HI. The control switch is stable in each of its opposite extreme positions. 
     A great advantage is its extreme simplicity, which results in only three major parts, namely the manually actuated switch, the controller, and the light constituting a load. 
    
    
     BRIEF DESCRIPTIONS OF THE INDIVIDUAL FIGURES OF THE DRAWINGS 
     FIG. 1 is a diagram of the circuitry of the apparatus. 
     FIG. 2 is a fragment of a circuit, which may be substituted for a corresponding fragment at the top of FIG.  1 . 
     FIG. 3 shows a chip that may be substituted for two chips at the lower right hand corner of FIG.  1 . 
     FIG. 4 is a semidiagramatic view of a new control switch, in N.O. position. 
     FIG. 5 is a view similar to FIG. 4 showing the switch in closed position. 
     FIG. 6 is a view of the switch of FIGS. 4 and 5 showing the switch OPEN in the extreme opposite position of the actuation lever relative to that FIG.  4 . 
     FIG. 7 is a view of another N.O. switch, similar in construction to that of FIG.  4 . 
     FIG. 8 is a view similar in construction to those of FIGS. 4 and 7 but of N.C. form. 
     FIG. 9 is a view of the kind of switch of FIG. 7, but of N.C. form. 
     FIG. 10 is a semidiagramatic view of a push button switch that is the equivalent in functioning to either of the switches of FIG. 4 or  7 . 
     FIG. 11 is a perspective view of an outlet box, of previously known kind. 
     FIG. 12 is a top view of a controller board of the present invention, positioned in a standard outlet box. 
     FIG. 13 is a large scale sectional view taken at line  13 — 13  of FIG.  12 . 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a power circuit or main circuit  20  of e.g. 120 VAC, having fuses  22 , and including an electric light  21  as a load. The apparatus finds most usage in a home where the load would a usually be a light bulb, but it is not limited to such and may be used in any of various settings, as in other structures, and the load may be a motor, or a pump, etc. 
     The circuitry of FIG. 1 other than the main AC source is preferably contained in a mechanical arrangement on a digital controller board  23  (FIGS. 3,  12 ) to be fitted in an existing outlet box already installed, described hereinbelow. 
     A transformer  24  reduces the 120 V to approximately 12 V, at the output  25 . Such transformer may be put out in a complete unit, but the device is also applicable instead to the usual transformer supplied for a doorbell which ordinarily produces approximately 24-30 V. In the latter case the transformer  27  of FIG. 2 may be utilized, having such output at  28  to which the conductors  30  are connected. 
     The conductors  30  lead from the transformer  24  (or  27 , FIG. 2) to a rectifier  31 , having an output conductor  33  leading to ground at  36   a , and another output  37 . The transformer  24  may be located anywhere in the house and the conductors therefrom lead to the controller board  23 . Ground connections are identified generally at  36 , individually identified with postscripts a, b, c, etc. 
     A conductor  41  leads from the rectifier output  37  through parallel capacitors forming filters  42  to a 7805 chip  44  having an output  45  leading to a contact post  46  of 5 VDC. The chip is grounded at  36   b.    
     The capacitors are selected in value and number according to whether the voltage is of 12 VDC or 24-30 VDC referred to above. 
     A switch unit is shown at  47 , at the lower left in FIG. 1, this unit including a plurality of N.O. switches shown diagramatically and referred to below. These switches individually identified with postcript letters, a, b, c, etc. are arranged in parallel, between ground  36   c  and contact post  48  in a conductor  48 ′ that leads from a contact post  49  of 5 V. Closure of any one of these switches  47  shorts the 5 V contact post  49  to ground at  36   c . A conductor  49 ′ leads from the contact post  48  to ground at  36   d . A conductor  50  leads from the post  49  to a contact post  50 ′ in a conductor  50 ″ leading to a JK flip flop chip  53 . 
     A conductor  51  leads from the post  48  to a Schmitt 7414 chip or inverter  51 ′, and the output of the latter is connected with a conductor  52  leading to the chip  53 . The chip  51 ′ serves to debounce the current to the chip  53 , although any chip with a toggle function could be used instead. The 7414 chip, of known kind, produces a change in the status of the circuit in response to successive pulses, that is, if the main circuit is ON, a pulse from one of the switches  47  changes it to OFF, while if the circuit is already OFF, the pulse will change it to ON. A capacitor  54  leads from post  3  to ground  36   e . Such a capacitor  54  leading to ground is also shown in FIG.  3 . The switches may be encapsulated and mounted in a standard 4″×4″ electric outlet box, known as a 1900 box. 
     Reference is now made to the pulsing toggle switches of FIGS. 4-9. These switches are basically similar in construction, but vary in details. The switches of FIGS. 4 and 7 are N.O., and the switches of FIGS. 8 and 9, are N.C. 
     Referring to FIGS. 4-6, a switch  60 , includes a frame  62  having contact posts  63 ,  64  connected in external circuit  64 ′. A conducting leaf spring  65  has a first end fixed to the post  63  and a swinging end  66  with a contact  67  thereon. 
     A fixed contact  69  connected with the post  64  is in position for engagement by the contact  67  upon swinging movement of the leaf spring. The leaf spring is shown in N.O. position, being self-biased to that position, although it may be biased by a compression coil spring if that should be found practical. The leaf spring has spaced straight segments  72   a ,  72   b , and a bowed element  73  therebetween. 
     The switch includes a manually actuated lever  75  pivoted at  76 , and having a point  77 , and a handle  78  for manual actuation. 
     In actuating the switch, the user grips the handle  78  and moves it from one extreme position to the other, and as here illustrated (FIG.  4 ), he moves the handle downwardly or counter-clockwise. The bowed element  73  has a convex surface directed toward the lever, and upon the lever engaging that bowed element in the swinging movement of the lever, the leaf spring is moved from its N.O. position in FIG. 4 to CLOSED position in FIG. 5, in which the contact  67  engages the contact  69  and closes circuit through the switch. Upon continued movement of the lever  75 , the point proceeds past the bowed element and into position adjacent the straight segment  72   a  (FIG.  6 ), enabling the leaf spring to spring back to its N.O. position shown. This movement of the lever is a single, continuous, momentary movement, and correspondingly, the closing of the contacts  67 - 69  is only momentary, providing a single momentary pulse in the circuit. 
     After such actuation, the switch rests in the position of FIG. 6 until it is actuated again,.and to so actuate it, the handle of the lever is gripped by the hand and moved clockwise, with the same sequence of OPEN-CLOSED-OPEN movement, the momentary closure again providing a single momentary pulse in the circuit. 
     In the switches of FIGS. 7,  8 ,  9 , the elements are given the same reference numerals as those of FIG. 4, but with single prime, double prime and triple prime indications respectively. 
     In FIG. 7, the switch  60 ′ is N.O., and structurally similar to that of FIGS. 4-6 but opposite and symmetrical in operation. It is pointed out that the bowed element  73 ′ has its concave side directed toward the lever. The leaf spring is self-biased to closed position, to the left of that shown, but held in OPEN position by the point of the lever engaging the straight segment  72   b ′. As will be obvious from the description of FIGS. 4-6, upon the point of the lever moving into register with the bowed element, the spring leaf moves into CLOSED position, and upon continued swinging movement of the lever, the point moves up and engages the straight segment  72   a ′ and again opens the switch. 
     The apparatus (FIG. 1) may utilize N.O. switches ( 47 ), i.e., those of FIGS. 4-6, and  7 , but the principles of construction of those switches can also be incorporated in N.C. switches, where the latter are used. The latter switches are shown in FIGS. 8 and 9. In FIG. 8, the leaf spring  65 ″ is self-biased to CLOSED position, i.e. in clockwise direction. The contact element  67 ″ is on the same side of the leaf spring as is the lever  75 ″, and when the leaf spring is so biased to CLOSED position, that contact engages the contact  69 ″. 
     In actuating this switch ( 60 ″), in the manner described above, the lever engages the bowed element and swings the contact  67 ″ to its dot-dash line position, i.e. to OPEN position, and upon further swinging movement of the lever, the point of the lever rides past the bowed element and enables the switch to move again to its CLOSED position. In either closed position, the point  77 ″ does not engage the leaf spring. 
     The construction of FIG. 9 is similar to that of FIG. 7, but is N.C. rather than N.O. In the present case the contact  69 ′″ is in engagement with the contact  69 ′″ in CLOSED position. Upon swinging movement of the lever (counter-clockwise), the point of the lever first enters into register with the bowed element, and the leaf spring self-biases to OPEN position i.e., clockwise, and upon still further movement, the point of the lever engages the straight element  72   a ′″ and again closes the switch. 
     In the use of all of the switches of FIGS. 4-9, the actuation consists of a full sweep movement of the lever, i.e. from one extreme position to the opposite extreme position, either clockwise or counter-clockwise, in each of the cases, and the switches act according to whether they are of N.O. or N.C. construction. Also an important feature of this construction is to be noted that the intermediate position occurs only momentarily and only a momentary pulse is produced in the circuit. It is not necessary for the user to make two movements of the switch, but only one. 
     The switches of FIGS. 4-9 in themselves constitute an invention and are so claimed. 
     The invention is of such breadth that the momentary pulse feature incorporated in switches of FIGS. 4-9, may instead be incorporated in the push button switch as shown in FIG. 10, for inclusion in the system of FIG. 1 instead of the switch  47 . This figure shows a push button switch  78 , including a push button  80  biased to OPEN position, i.e. to the left in FIG. 10, by a compression spring  81 . The contacts  67  and  69  are shown, the former being mounted on the leaf spring  65 . Upon the user depressing the push button, to the right in FIG. 10, it pushes the contacts into engagement, and upon release, the push button retracts, enabling the leaf spring to retract under its biasing action. The feature in common with the other switches is that upon merely depressing the push button in one movement, the momentary pulse is produced, and upon releasing the push button, it moves to OPEN position. 
     The system of FIG. 1 is mounted on the controller board  23 , (FIGS. 3,  12 ), but FIG. 3 shows a Schmitt chip  80 , and a JK flip flop chip  82 . Input  83 , output  85 , ground  86  are shown, and a 5 V contact post  87  is included. The chip  82  includes contact posts  88  that are included in the chip  53  of FIG. 3, but selected therefrom and incorporated in the chip  82  of FIG.  3 . The contact posts  88  include an input J, an input K, a clock impulse Cp, an asynchronous reset Ar, and an output Q. The chips  80  and  82 , themselves, to the exclusion of others, together form a new chip herein disclosed and claimed, which can replace the chips  51 ′ and  53 , of FIG.  1 . The relay  85  (FIG. 1) is not included in the new chip. 
     The following is a summary of the main features of the apparatus of the invention. A low voltage control circuit is provided with one or more toggle switches modified to send a single pulse developed in the control circuit for controlling the main circuit. 
     The output of the 7414 chip  51 ′, directed to 74LS76 chip,  53 , providing the feature that for each pulse of the input, the output will be changed from ON to OFF, or OFF to ON. 
     The output from the chip  53  is utilized to actuate a relay switch  90 , preferably SSR (FIG. 1 lower right), the input  90   a  being in the low voltage circuit, and the contacts  90   b  in the main high voltage circuit (FIG. 1 lower left). An SSR is preferably used, but it is within the scope of the invention to utilize a mechanical relay instead, if desired. The size of the load determines the size of the relay to be used. 
     The foregoing elements of the, low voltage control circuit are mounted on the controller board  23 , which is in the form of a printed circuit board, forming a digital component. 
     An important feature of the invention is the mounting of such printed circuit board in a standard metal outlet box. Such an outlet box is shown at  91  in FIG. 11, having a bottom element or plate  92 , and a surrounding wall  93 , the wall having a plurality of knock-outs  95 , which include disks which can be easily knocked out leaving holes  96  for running wires therethrough. The bottom element  92  is provided with a threaded hole  97  for receiving a mounting screw for mounting the box in place in the building. A ground line  97  leads from the box to ground at  36   f.    
     The controller board  23  is of flat form and smaller than the IFS knock-out box and easily fits within it. FIG. 13 shows a structural element  98  of the building, and the outlet box  91  mounted thereon. The hole  97  is here indicated for receiving a screw  103  for mounting both the outlet box and digital controller board on the structural element  98 . 
     The controller board  23  includes a main panel  100  and a layer of insulation  102 , and the screw  103  is inserted through the hole  97  in the controller board and the insulation layer into the structural element  98 . The controller board has a conducting element  105 , such as solder, (FIG. 13) on the screw for grounding the desired elements of the printed circuit board. Leading from this solder element is a conductor  106  (see also FIG. 12) for connecting the various conductors in the printed circuit board. 
     The completed circuit board is placed in the knock-out box, and as in usual procedure, the knock-out disks are knocked out as desired, and then the external wiring is inserted through the holes. Thereupon a cover may be reapplied to the knock-out box. 
     Suitable releasable catch means  108  (FIG. 12) of known kind and here shown diagrammatically, may be utilized for temporarily holding the controller board in the knock-out box in the installing steps. 
     This mounting of the circuit board constitutes conversion of original wiring in a building, to control by a low voltage, digital control circuit. However, in a new installation, a complete new box with the components therein is utilized. 
     End of descriptive specification