Abstract:
The circuit includes a super regenerative detector (12) for receiving a modulated radio frequency signal from a transmitter. The output of the super regenerative detector is amplified and sent into a high frequency interpreter circuit (16, 18, 20) which de-modulates the signal creating an output of low frequency equal to the consecutive pulses frequency. The low frequency signal is received by a low frequency interpreter circuit (22, 24, 26) which outputs a digital signal of a single duration which is received by a counter circuit (30). The counter circuit (30) controls the firing of a triac (T1) to create lighting conditions of on, off and dimming.

Description:
TECHNICAL FIELD 
     The subject invention relates to remotely controlled dimmer circuits which are utilized with a light. 
     BACKGROUND ART 
     Dimmer circuits are extensively utilized in devices requiring a variable amount of power. This is typically accomplished by either a manual potentiometer switch that is manually turned by the operator, or a remotely controlled circuit. In the manual potentiometer, the operator is required to be at the location of the switch. Remotely controlled circuits use counters to count the number of pulses to activate a relay to vary the amount of power delivered to the load. One such circuit receives a single radio frequency signal from a transmitter. The signal is amplified, limited, filtered and detected. The output of the circuit is a digital signal which is sent into a counter means. The counter reacts to the duration of the digital signal which changes the firing phase of a triac to illuminate the light to the requested lighting condition. An inadequacy of this circuit is that the circuit uses a single frequency which allows for error from noise and other transmitters by interfering with the circuit function. 
     SUMMARY OF THE INVENTION 
     The subject invention relates to a dimmer control circuit for respectively turning on, off, and dimming a light. The circuit contains a super regenerative detector for receiving a modulated radio frequency signal within a predetermined frequency range from a transmitter. A light control means connects between a light and an electrical power outlet and is responsive to the detector for independently controlling the electrical power supplied to the light in a series of stepped levels in response to the duration of the modulated radio frequency signal detected by the detector. The circuit is characterized by the light control means including a counter circuit and high frequency and low frequency interpreter circuits in series for producing a digital signal to drive the counter circuit to adjust the phase angle of a pulse to control the amount of power supplied to the light. 
     The subject invention solves the inadequacy of the prior art of interference by noise or other transmitters, by having the circuit receive a two tone modulated radio frequency signal to ensure the circuit reacts only when the transmitter is transmitting. 
    
    
     BRIEF DESCRIPTIONS OF THE DRAWINGS 
     Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing which is a schematic of the receiver portion of a preferred circuit of the subject invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A remotely controlled dimmer circuit is generally shown at 10 in the drawing. The circuit 10 supplies power to an electrical device or load requiring electrical power from a constant source. The circuit can be used with any device requiring power from a conventional electrical power source for electrically supplying power to the electrical load in response to a predetermined radio signal. A modulated radio frequency signal sent from a transmitter and is detected and interpreted creating a digital signal whose pulse duration is transformed into the phase firing to illuminate a light or load. 
     A super regenerative detector 12 receives the modulated radio frequency signal which is within a predetermined frequency range from a transmitter. The predetermined frequency range is determined by the value of components used as indicated hereinafter. The super regenerative detector 12 includes a coupling inductor L1 connected in parallel with a capacitor C1 to define a tuned circuit. A capacitor C2 connects the collector and emitter of a transistor Q1. A resistor R2 and a capacitor C4 are in parallel which are connected to the base of the transistor Q1. The collector of the transistor Q1 is connected to an inductor L2 acting as an isolation choke which is connected to a capacitor C3 between two parallel resistors R3, R4. A resistor R1 taps the inductor L1. A resistor R5 and capacitor C5 connects the circuit to the supply power line for setting a time constant. 
     The signal from the super regenerative detector 12 is sent into an audio amplifier 14 to amplify the signal to a magnitude which can be interpreted. A operational amplifier U1 is biased by three resistors R6, R7, R8 which are connected to the inverting and noninverting inputs. The inputs are separated by a capacitor C7. The operational amplifier U1 has inverting feedback through a resistor R9. Two parallel capacitors C6, C8 connect the audio amplifier 14 to the power line for setting a time constant. 
     The amplified signal from the audio amplifier 14 is sent into a high frequency interpreter circuit 16, 18, 20. The high frequency interpreter circuit transforms the amplified, modulated radio frequency into a low frequency signal which has low frequency pulse durations equal to the duration of consecutive pulses of the high frequency input signal. The high frequency interpreter circuit includes a limiter 16, a high tone filter 18, and a detector 20. The limiter 16 adjust the magnitude of the signal to be within a predetermined range. The components of the limiter 16 include an operational amplifier U2 with an inverting input connected to the output of the audio amplifier 14 and the noninverting input is biased by two resistors R10, R11 which is connected to the output of the audio amplifier 14. A capacitor C9 connects the circuit to the power line. 
     The high tone filter 18 filters out frequencies above a predetermined allowable frequency to eliminate noise and miscellaneous transmitted signals the super regenerative detector 12 picks up. The high tone filter 18 includes an operational amplifier U3 with inverting feedback to configure the filter which has a resistor R14 connected between two parallel capacitors C10, C11. The capacitors C10, C11 are connected to the output of the limiter 16 through two biasing resistors R12, R13. A resistor R17 biases the noninverting input of the operational amplifier U3. 
     The detector 20 creates a signal of a signal duration equal to the duration of the low frequency pulses indicative of the amount of dimming control. The detector 20 acts as a peak smoothing circuit which charges a capacitor C13, which remains charged until the consecutive high frequency pulses have passed. The capacitor C3 will output a high signal for the duration of consecutive high frequency pulses. The detector includes a diode D1 connected to the output of the high tone filter 18 which is connected to the capacitor C13. 
     The signal from the high frequency interpreter circuit 16, 18, 20 is sent to the low frequency interpreter circuit 22, 24, 26. The low frequency interpreter circuit 22, 24, 26 transforms the output of the high frequency interpreter circuit 16, 18, 20 into a digital signal of a pulse equal in duration of the low frequency input signal which is proportional to the amount of dimming requested. The low frequncy interpreter circuit includes a limiter 22, a low tone filter 24, and a detector 26. 
     The limiter 22 is connected to the output of the high frequency detector 20 and is used for setting the signal magnitude within a predetermined range. The limiter 22 includes an operational amplifier U4 with noninverting feedback which is connected through three resistors R18, R19, R20 to the diode D1 of the detector 20. The inverting input is biased by a pair of resistors R15, R16 and a capacitor C12. 
     The low tone filter 24 receives the output from the limiter 22 and is used for filtering out frequencies below a predetermined allowable frequency to ensure that the signal received is from the transmitter. The low tone filter 24 includes an operational amplifier U5 with biasing resistors R21, R22. The operational has inverting feedback through resistor R23 and parallel capacitors C14, C15. 
     A detector 26 is connected to the output of the low tone filter 24 and is used for creating a single of a signal duration equal to the duration of the low frequency pulses indicative of the amount of dimming control. The detector 26 includes a diode D2 connected to the output of the low tone filter 24 and connected to a capacitor C16 and resistor R24 in parallel. 
     The light control means also includes a threshold detector 28 which receives the signal from the detector 26 of the low frequency interpreter circuit to ensures that the magnitude of the signal is within the predetermined range for driving the phase firing of the power to the load. The threshold detector includes an operational amplifier U6 biased by two resistors R26, R27 with noninverting feedback through resistor R25. The inverting input is connected to the diode D2 of said detector 26 of said low frequency interpreter circuit. 
     A counter circuit 30 receives the digital signal from the threshold detector 28. The counter circuit 30 includes a triac T1 and an integral circuit chip U7. The integrated circuit chip U7 acts as a counter reacting from the duration of the signal coming from the threshold detector 28 which counts based on time intervals which establishes the phase of firing of the triac to a illuminate the light to the requested lighting condition. A diode D3 is connected between the integrated circuit chip U7 and the triac T1 for driving the gate and phase controlling the triac T2 to illuminate the light or load 32 to the proper dimming condition. 
     The light control means also includes a touch control means 34 connected directly to the counter circuit 30 for changing the light conditions by touching a metal plate 36 of the lamp. The integral circuit chip U7 reacts from the duration of the touch. The touch dimmer circuit 34 includes a pair of large resistors R30, R31 connected between a pin of the integrated circuit chip U7 and a metal plate 36 designed for human contact. A resistor R29 and a capacitor C22 are in shunt which are connected between a power supply circuit 38 and a pin of the integral chip U7. 
     A power supply circuit 38 is connected between the counter circuit 30 and the power leads for supplying power to the circuit and to the light or load 32 through the counter circuit 30. The power supply circuit includes a resistor R28 and a capacitor C18 interconnect the power output and counter circuit 30 for a counter reset. A capacitor C17 connects to the integrated circuit chip U7 to prevent triggering of the counter circuit U7. A capacitor C21 interconnects the power input to prevent shorting. A blocking diode D6 interconnects the power input leads to protect the circuit 30 against voltage surges from a constant power source. A zener diode D5 and a capacitor C20 connects the power input to the inductor L3 to limit the charge stored in the inductor L3. A diode D4 and capacitor C19 connect the power supply circuit 38 to ground. Thus,a first duration, typically less than on second, of the radio frequency signal will energize the counter circuit 30 by having the integrated circuit chip U7 fire a gate pulse to the triac T1 causing the triac T1 to conduct. The integrated circuit chip U7 will hold the previous power magnitude level in memory. So, once the counter circuit is energized, a longer duration of the radio frequency signal will cause the counter circuit 30 to count up or down and increase or decrease the amount of power supplied to the light or load 32. Another short duration pulse will deenergize the counter circuit 30 and cut the power to the light or load 32. 
     By way of example, and certainly not way of limitation, the preferred embodiment of the circuit illustrated may include the following components. 
     
         ______________________________________Name              Value______________________________________ResistorsR1                4.7KR2                10KR3                470R4                3.3KR5                10 LR6                4.7KR7                10KR8                10KR9                1 mR10               10KR11               1 MR12               (a)200K, (b)270K,             (c)330KR13               (a)1.05K, (b)1.33K,             (c)1.74KR14               (a)422K, (b)536K,             (c)681KR15               22KR16               .8KR17               27KR18               220KR19               100K             MR21               390KR22               3.32KR23               806KR24               100KR25               2.2 MR26               27KR27               47KR28               1.5 MR29               330R30               330CapacitorsC1                3.3 pC2                5 pC3                1 nC4                100 pC5                100 mfd/10 vC6                4.7 nC7                1 nC8                10 mfd/25 vC9                10 mfd/25 vC10               4.7 nC11               4.7 nC12               10 mfd/25 vC13               22 nC14               22 nC15               22 nC16               1 mfd/25 vC17               4.7 nC18               47 nC19               470 pC20               100 mfd/25 vC21               .68 mfd/250 vC22               .1 mfd/250 v______________________________________Name              Type______________________________________DiodesD1                1N4148D2                1N4148D3                1N4004D4                1N4004D5                1N 4744AD6                MOVIntegrated Circuit ChipsU1, U2, U3, U4    LM324U5, U6            LM358U7                LSI 7232TransistorsQ1                NSClTD.9018InductorsL1                3 loops, 1/4 D × 3/4             paper form, 1/4 D × 7/8             slugL2                .47 MHL3                80 MHTriacT1                teccor Q4006 L4______________________________________ 
    
     As shown in the component list the resistors R12, R13, and R14, can have different values as indicated by (a), (b), and (c). By using either the first set, second set, or third set of values, a different frequency will be detected from the transmitter. The first set of values will detect a signal of a 147.5 microsecond high frequency radio signal. The second and third set will detect a 187.7 microsecond and a 241.1 microsecond high frequency radio signal respectively. The low frequency signal is set at 11.83 milliseconds. 
     The invention has been described in an illustrative manner and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. 
     Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims wherein reference numerals are merely for convenience and are not to be in anyway limiting, the invention may be practiced otherwise than as specifically described.