Abstract:
A system for providing one or more voltages at predetermined magnitudes. The system may be supplied with power having a range of voltage magnitudes without affecting the predetermined magnitudes of the one or more voltages provided by the system and without a need to change circuitry of the system. The system may be connected, for example, from 28 VDC to 250 VAC without affecting the predetermined magnitudes of the output voltage or voltages. This system is protected from a mistaken power hook-up thought to be for 28 VDC but actually being connected to 250 VAC, which could be a disaster for a system not having the present circuitry. The system may be used for supplying power for opto-couplers in relay detection and other applications. The system may incorporate lightning and reverse polarity protection, reference and regulated voltages, an output driver, and input isolation circuitry.

Description:
[0001]    The present application claims the benefit of U.S. Provisional Patent Application No. 62/057,694, filed Sep. 30, 2014. U.S. Provisional Patent Application No. 62/057,694, filed Sep. 30, 2014, is hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The present disclosure pertains to power supplies and particularly to voltage sources. 
       SUMMARY 
       [0003]    The disclosure reveals a system for providing one or more voltages at predetermined magnitudes. The system may be supplied with power having a range of voltage magnitudes without affecting the predetermined magnitudes of the one or more voltages provided by the system and without a need to change circuitry of the system. The system may be connected, for example, from 28 VDC to 250 VAC without affecting the predetermined magnitudes of the output voltage or voltages. This system is protected from a mistaken power hook-up thought to be for 28 VDC but actually being connected to 250 VAC, which could be a disaster for a system not having the present circuitry. The system may be used for supplying power for opto-couplers in relay detection and other applications. The system may incorporate lightning and reverse polarity protection, reference and regulated voltages, an output driver, and input isolation circuitry. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0004]      FIG. 1  is a diagram of an illustrative instance of a present system; 
           [0005]      FIG. 2  is a diagram of an example circuit of the present opto-coupled voltage input mechanism or system; 
           [0006]      FIG. 3  is diagram of a graph  95  showing some waveforms from system; and 
           [0007]      FIG. 4  is a diagram that shows a possible application of system for providing a bias on line to a number of opto-couplers for some devices. 
       
    
    
     DESCRIPTION 
       [0008]    The present system and approach may incorporate one or more processors, computers, controllers, user interfaces, wireless and/or wire connections, and/or the like, in an implementation described and/or shown herein. 
         [0009]    This description may provide one or more illustrative and specific examples or ways of implementing the present system and approach. There may be numerous other examples or ways of implementing the system and approach. 
         [0010]    Controller designs may have multiple versions of the control to be able to handle different levels of digital signal input voltages, in order to cover the range of voltages used in applications of the control for different needs and locales around the world. The controller&#39;s input circuits may have different values of electronics components to operate in systems that range from low to relative high voltages. 
         [0011]    Controllers and voltage systems referred to herein may have application to components of heating, ventilation and air conditioning (HVAC) systems. 
         [0012]    The need to interface for various voltage supply values may result in a proliferation of many versions of a controller and complicate inventory and selection for those who sell, purchase, and provide services for these systems. It may also complicate the work of an installer who can destroy a controller by accidentally choosing a version that is the wrong voltage for the system. 
         [0013]    Additionally, a use of resistive voltage dividers to reduce high voltages down to the signal levels needed by control logic may result heat build-up and thermal stress generated by these circuits which can create issues in lower device ratings, increased costs due to more cooling equipment, and higher component failure rates. 
         [0014]    The present system may consist of a universal opto-coupled input circuit that automatically adapts to any AC or DC input voltage in the nominal range from about 15 to 300 volts RMS DC and AC. 
         [0015]    The circuit may be accomplished by using a bias generator circuit that uses line voltage levels to generate a proportional output voltage that is sent to each of the multiple opto-coupled input signal circuits. The voltage may bias input circuits to operate in the correct active range for the opto-couplers. Bias voltages and the design of the input circuits may automatically limit the opto-coupler input current to an appropriate value. The present approach may achieve without a need for different voltage dividers or input circuits. A single circuit with fixed values may work correctly over the entire line voltage range. 
         [0016]    Additionally, the present bias circuit may incorporate an ability to turn on virtually all inputs just when an input measurement is actually occurring. In a microcomputer-based control, the inputs may be measured and actually needs to be active for only a small percentage of time. One example is a line voltage input scheme that takes three samples of the input status, separated by 1 millisecond, at the positive peak of each line cycle. This scheme requires the inputs to be active for only 2 to 3 milliseconds during each 16.6 millisecond period (60 Hz line voltage provides a 16.6 millisecond cycle time). So although a typical opto-coupled circuit could be active during the entire positive alternation, or 8.3 milliseconds, the approach would allow these to be on only during a time of less than 3 milliseconds. Taking sine wave effects into account, the present approach may decrease internal power dissipation by at least 50 percent. 
         [0017]    The present approach does not necessarily need different circuits (and thus different products) for different line voltages. The approach may easily turn inputs on just when needed. The approach may be integrated with compatibility to multiple line voltages. 
         [0018]    The electronics of the present system may be included in a controller that provides two terminals to connect the line voltage to the bias circuit (power and neutral). There may be one terminal for each line voltage input signal along with one common terminal, to connect it to a corresponding opto-coupled input. 
         [0019]      FIG. 1  is a diagram of an illustrative instance of a present system  10  for providing a safe and consistent voltage output  18  for application of various circuits such as opto-couplers, by using a system voltage  39  that may be of various magnitudes, ranging from a few tens of volts to several hundred volts, without a need to change the circuitry of system  10 . System voltage  39  may be provided via lines  11  and  12  to a protection circuit  13 . An output from protection circuit  13  may go a reference and regulation circuit  14 ,  15 . An output of circuit  14 ,  15  may go to an output driver  14 . An isolation circuit  16  may have an input  17  for an enable signal. The enable signal, after going through an opto-coupler, may go to driver  14 . A reference signal may be presented at an output  18  of driver  14 . 
         [0020]      FIG. 2  is a diagram of an example circuit of the present opto-coupled voltage input mechanism or system  10 . System voltage  39  may be applied to lines or terminals  11  and  12  ranging from about 15 volts to 300 volts RMS DC or AC. A sub-circuit  13  for protection may be connected to terminals  11  and  12 , and overlap and be connected with a regulator sub-circuit  14 . Regulator sub-circuit  14  may be connected to a network sub-circuit  15 . An isolation sub-circuit  16  may be connected to network  15 . An enable signal  21  may be provided to an input  17  of isolation sub-circuit  16 . 
         [0021]    A connection  18  may go from regulation sub-circuit  14  to an opto circuit  21  and a connection  19  may go from sub-circuit  15  to opto circuit  22 . Connection  18  may be a reference for opto circuits  21  and  22 . Connection  19  may be an input for reference opto circuit  21 . 
         [0022]    Switch or relay contacts  23  associated with a switch mechanism may be monitored by opto circuit  22 . A line  24  may provide a high reference voltage from terminal  11  to an input  25  of opto circuit  22 . An output  26  with an opto reference sync from opto circuit  21  may go to a processor  27 . An opto in signal  28  from opto circuit  22  may go to processor  27 . Other opto circuits like opto circuit  22  may be present to monitor switch or relay contacts. These circuits, along with their corresponding contacts, may be connected to a reference provided by connection  18  and line  24 , respectively, in like manner for opto circuit  22 . 
         [0023]    Sub-circuit  13  may have a varistor  31  (B72214P2321K101) connected across lines  11  and  12 . A 100 ohm resistor  32  may have one end connected to line  11  and another end connected to an anode of a diode  33  (S1G-13). A cathode of diode  33  may be connected to line  19 . A 100 ohm resistor  34  may have one end connected to line  12  and another end connected to a cathode of a diode  35  (S1G-13). An anode of diode  35  may be connected to a line  36 . A varistor  37  (B72660M0271K072), may have one end connected to line  18  and another end connected to line  36 . Varistors  31  and  37  and resistors  32  and  34  may provide protection against lightning and electro static interference. Diode  33  and  35  may provide reverse polarity protection. If system voltage  39  is conditioned, then varistors  31  and  37  and resistors  32  and  34  are not necessarily needed for lightning and electro static interference. 
         [0024]    Sub-circuit  14  may have a PNP transistor  41  (FZT560TA) with an emitter connected to line  18 , a collector connected to line  36 , and having a base. Transistor  41  may be attached to a heat sink  42 . A PNP transistor  43  (FZT560TA) may have a collector connected to the base of transistor  41 . Transistor  43  may have an emitter and a base. A zener diode  44  (MMSZ471T1G) may have an anode connected to line  18  and a cathode connected to the base of transistor  43 . A 10K ohm resistor  45  may have one end connected to line  19  and another end connected to the cathode of zener diode  44 . The emitter of transistor  43  may be connected to line  19  directly or via a low ohm resistor  46 . 
         [0025]    Network sub-circuit  15  may have a 24K ohm resistor  51  with one end connected to the base of transistor  41  and having another end connected to a one end of a 102K ohm resistor. Another end of resistor  52  may be connected to line  19 . A 0.0022 microfarad capacitor  53  may be connected in parallel with resistor  51 . A 20K ohm resistor  54  may have one end connected to line  36  and have another end. 
         [0026]    Isolation sub-circuit  16  may have an opto coupler  61  (MOC8204SR2M) with a light emitting diode  62  and a light sensitive photo NPN transistor  63 . An anode of transistor  62  may be connected to one end of a 100 ohm resistor  64 . Another end of resistor  64  may be connected to a plus 33 volt supply terminal  65 . A cathode of diode  62  may be connected to input  17 . Transistor  63  may have a base connected to another end of resistor  54 , and an emitter connected to line  36 . A collector of transistor  63  may be connected to the end of resistor  51  not connected to the base of transistor  41 . 
         [0027]    If an enable signal is applied to input  17 , transistor  43  may turn on. As a result, transistor  41  may turn off. Capacitor  53  may improve the turnoff speed of transistor  41 . 
         [0028]    Opto circuit  21  may have a 12K ohm resistor  71  with one end connected to line  19  and another end connected via line  20  to an opto coupler  72  (MOCD207M) having a light emitting diode  73  with an anode connected to the other end of resistor  71  and a cathode connected to line  18 . Opto coupler  72  may also have a light sensitive photo NPN transistor  74  with a collector connected to line  26  and an emitter connected to a ground  76 . The collector of transistor  74  may also be connected to one end of a 56K ohm resistor  75 . Another end of resistor  75  may be connected to a plus 3.3 volt supply terminal  65 . A diode  77  (BAV21W) may have a cathode connected to the other end of resistor  71  and an anode connected to line  18 . Diode  77  may provide reverse polarity protection. A 0.047 microfarad capacitor  78  may be connected in parallel with diode  77 . 
         [0029]    Opto circuit  22  may have a 12K ohm resistor  81  with one end connected to terminal or line  25  and another end connected to an anode of a diode  82  (S1G-13). A cathode of diode  82  may be connected to an anode of a light emitting diode  84  of an opto coupler  83 . A cathode of diode  84  may be connected to line  18 . Opto coupler  83  may also have a light sensitive photo NPN transistor  85  with a collector connected to line  28  and an emitter connected to ground  76 . The collector of transistor  85  may also be connected to one end of a 56K ohm resistor  86 . Another end of resistor  86  may be connected to plus 3.3 volt supply terminal  65 . A diode of 87 (BAV21W) may have a cathode connected to the cathode of diode  82  and an anode connected to line  18 . Diode  87  may provide reverse polarity protection. A 0.047 microfarad capacitor  88  may be connected in parallel with diode  87 . 
         [0030]      FIG. 3  is diagram of a graph  95  showing some waveforms from system  10  and some of the opto-couplers  72  and  83  having outputs  26  and  27 , respectively, to processor  27 , while system  10  is operating. Signal L may be detected on terminal or line  11 . Signal B may be detected on line  18 . Signal M may be detected on line  20  of opto-coupler circuit  21 . Signal D may be detected on terminal  25  at contacts  23  and an input of opto-coupler  22 . The abrupt down movement of a waveform portion  91  of signal D may reveal an opening of switch or relay as indicated by contacts  23 . Signal C may be detected on line  19  going to opto-coupler  21 . Signal H may be detected on line  28  from opto-coupler  22  to processor  27 . A waveform portion  92  of signal H may be low to indicate open contacts  23 . Signal G may be detected on line  26  from an output of opto-coupler  21  to processor  27 . Signal A may be provided on line  17  to opto-coupler  61  of isolation circuit  16 . 
         [0031]    Graph  95  may have a timeline at a bottom axis  93  that goes from about 0.00 milliseconds to 16.67 milliseconds that is a time period of one cycle of a 60 Hz AC power signal. A left axis  94  of graph may show a magnitude scale for each of the signals. Voltage scales for signals L, B, M, D and C may range from −350V to 350V. Voltage scales for signals H and G may range from 0.3V to 3.3V. The voltage scale for signal A may range from 1.0V to 3.4V. 
         [0032]      FIG. 4  is a diagram that shows a possible application of system  10  for providing a bias on line  18  to a number of opto-couplers for a burner control (BC) and for an IO module line voltage mechanism. A system voltage (Vref) may be provided to system  10  on lines  11  and  12 . 
         [0033]    To recap, a voltage circuit system may incorporate input terminals for connection to a first voltage, a regulator connected to the input terminals, an output driver connected to the regulator and for providing a second voltage, and an isolator connected to the output driver. The isolator may incorporate an opto-coupler. The first voltage may be of a power source. The second voltage may be a reference voltage. The first voltage may have a magnitude between one and twenty times greater than a magnitude of the second voltage without affecting the magnitude of the second voltage. 
         [0034]    The system may further incorporate a protection circuit connected between the input terminals and the first voltage. The protection circuit may guard against harm from lightning and reverse polarity to the regulator, the output driver, and the isolator. 
         [0035]    At least one of a set of contacts of a relay that provides a connection to an opto-coupler circuit may have a magnitude of the first voltage. 
         [0036]    The first voltage may range from a nominal voltage of about 15 volts RMS to 300 volts RMS, DC or AC, without affecting the regulator, output driver, and isolator. 
         [0037]    The protection circuit may be unneeded if a conditioned power source is connected to the input terminals in lieu of the first voltage and prevents effects caused by lightning and reverse polarity to the isolator, output driver, and isolator. 
         [0038]    An opto-coupled voltage mechanism may incorporate a protection module, a reference and regulation module connected to the protection module, an output driver connected to the reference and regulation module, and an isolation module connected to the output driver. The protection module may have an input for a system voltage. The isolation module may have an input for an enable signal. The output driver may have an output for providing a reference voltage. The system voltage may vary from a first value up to at least an order of magnitude greater than the first value, while the reference voltage remains at a second value. 
         [0039]    The isolation module may incorporate an opto-coupled circuit having the input for an enable signal and an output to the output driver. 
         [0040]    The system voltage may be between 15 volts RMS to 300 volts RMS, AC or DC. 
         [0041]    The mechanism may further incorporate a reference opto-circuit connected to the output of the output driver for a reference voltage and to an output of the protection module, and for providing an opto reference sync signal. 
         [0042]    The mechanism may further incorporate a processor having an input connected to the reference opto-circuit for receiving the opto reference sync circuit signal. 
         [0043]    The mechanism may further incorporate one or more switch detection opto-couplers. Each switch detection opto-coupler may have a first terminal connected to a first contact of a set of contacts, for a switch, having a second contact for connection to the system voltage. Each switch detection opto-coupler may have a second terminal connected to the output of the output driver for a reference voltage. 
         [0044]    The one or more switch detection opto-couplers may be turned on for a predetermined percentage of the total time of a cycle of power to the mechanism. 
         [0045]    Since the one or more switch detection opto-couplers may be active for predetermined percentage of time, power dissipation of the mechanism may be decreased by at least 50 percent. 
         [0046]    An approach for adapting a circuit to a supply voltage of various magnitudes, may incorporate generating one or more output voltages having constant levels from various supply line voltage levels, and conveying the one or more output voltages to one or more opto-coupled signal circuits. The one or more output voltage may bias one or more opto-coupled signal circuits to operate in a correct active range, and limit current to the one or more opto-coupled signal circuits to a magnitude appropriately safe for the one or more opto-coupled signal circuits. 
         [0047]    The approach may further incorporate turning on the one or more opto-coupled signal circuits when or only when an input measurement is occurring. 
         [0048]    An input measurement via an opto-coupled signal circuit may need to be active for just a fraction of a contiguous amount of time of a cycle of a supply line voltage available for the input measurement. 
         [0049]    The fraction may be equal to or less than fifty percent. 
         [0050]    The various supply line voltage levels may range from 15 volts to 300 volts RMS, DC or AC. 
         [0051]    Each output voltage may have a preselected constant magnitude. 
         [0052]    Power dissipation by the one or more opto-coupled signal circuits may decreased up to fifty percent due to turning on the one or more opto-coupled signal circuits when or only when an input measurement is occurring. 
         [0053]    Any publication or patent document noted herein is hereby incorporated by reference to the same extent as if each individual publication or patent document was specifically and individually indicated to be incorporated by reference. 
         [0054]    In the present specification, some of the matter may be of a hypothetical or prophetic nature although stated in another manner or tense. 
         [0055]    Although the present system and/or approach has been described with respect to at least one illustrative example, many variations and modifications will become apparent to those skilled in the art upon reading the specification. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the related art to include all such variations and modifications.