SYSTEM FOR OPERATING A LAMP
BACKGROUND OF THE INVENTION The invention relates to a system for operating a lamp consisting of: - two input terminals for connection to a sine-wave supply source, encoding mechanisms coupled to said input terminals to disturb part of a number predefined half-periods of a sine-wave supply, said predetermined number of half-periods of the sine-wave supply as a whole form a control period, - a self-regulating inductor circuit equipped with - self-regulating inductor input terminals that are coupled to said coding mechanisms during the operation of the lamp to receive the disturbed supply sinewave voltage, - mechanisms I to generate a lamp current outside the disturbed sinewave supply voltage,
- mechanisms II coupled to the mechanisms I to control an operation characteristic of the lamp depending on a control signal, - decoding mechanisms to generate the control signal depending on the silhouette of the control period. The invention also relates to coding mechanisms and to a self-regulating inductor circuit for use in such a system. Such a system is known from the US document. 5,068,576. In the known system, the coding mechanisms completely cut off or reduce the magnitude of an entire half period, so that there is a missing pulse or a pulse of a significantly reduced voltage at the rectified DC output of the rectifier contained in the inductor circuit autoregulator In the discovered self-regulating inductor, the operating characteristic of the lamp qμa is controlled is the light output. The period of time between the successive missing pulses represents the control knob. For example, the time "n" between the missing impulses can represent a 70% level of regulation, while the time "m" between the missing impulses represents 90% of the level of regulation. A missing pulse means an interruption of the supply voltage and will cause the lamp operated by a self-regulating inductor to flicker. In the self-regulating inductor with the step of uncovered regulation, the flickering is not objectionable, since the user expects a significant and abrupt change in the light output of the lamp when a light level is e.g. 90% to the next, e.g. 75% However, when a continuous regulation effect is desired, i.e., when the light is to be smoothly adjusted in small pieces, it will be objectionable for the user to cut off the entire pulses of the main supplies (and the resulting flicker). The purpose of the invention is to provide a system for operating a lamp that consists of an improved communication between the coding mechanisms and the self-regulating in-ductor which solves the previously mentioned disadvantages. A system for operating a lamp as described in the introduction paragraph is in accordance with the invention, characterized in that the perturbations applied by the coding mechanisms change the amplitude of the supply sinewave voltage of only a part of each medium disturbed period of the supply sinewave voltage. In this way, the disturbances encoded in the line voltage with the coding technique according to the invention can be chosen so small that the lamp can not be peeled even with signals encoded in the supply vol- ume. It has been found that, depending on the configuration of the self-regulating inductor circuit, the part of the half-period that is disturbed can be chosen between 10% and 50% of the half-period, preferably between 10% and 25%. Preferably, the disturbance is also a phase cut. Phase cuts can be chosen less than
45 degrees, preferably about 30 degrees. In this way the disturbances encoded in the line voltage in the theoretical encoded according to the invention, can be very small so that the eyelid of the lamp is effectively avoided. The use of a constant phase cut as a disturbance allows a relatively simple use for the encoder and decoder circuits. Preferably, the decoding mechanisms consist of mechanisms to differentiate the disturbed sinewave supply voltage. The decoding by means of differentiation of the waveform allows the disturbance to be so small to minimize disturbances in the supply voltage signal. In a favorable embodiment of the system for operating a lamp according to the invention, the mechanisms for controlling the operation characteristic of the lamp increase said operation characteristic by means of a predetermined amount when a first silhouette of the control period is detected. by the decoding mechanisms and decrease the operating characteristic of the lamp by means of a predetermined amount when a second silhouette of the control period is detected by the decoding mechanisms. The mechanisms for controlling an operating characteristic of the lamp may, for example, be control mechanisms for controlling the light output of the lamp. No disturbances are introduced into the voltage line unless a change in the operating characteristic of the electric lamp is desired. This has the advantage that when the lamp remains constant, no disturbances are imposed on the main voltage, so that the flicker of the lamp is avoided by complex. This is significant, since for the purposes of general lighting, the amount of time a lamp remains at the same level of light, far exceeds the very limited time frame in which the level of light is actually changing. This is in contrast to electronic and triac regulators where intermediate light levels and fa-se cuts are continuously imposed on each cycle of the main voltage. Said control period may be formed by two successive half-periods of disturbed supply voltage and half periods without disturbing each other, and the signal may depend on the time duration of the control period. On the other hand, said control period may comprise a fixed number of half periods of supply sine-wave voltage. In the latter case, the signal may depend on the number of disturbances in a control period. In that case, the coding and decoding mechanisms can be of a relatively simple construction. Additionally, it is possible for the control period to represent a binary figure, each half undisturbed period of each control period corresponds to "0" (zero) and each half period disturbed corresponds to "1" (one). In this way, many controls can be accommodated in a period of control. Of course, an equivalent possibility may be that the control period represents a binary figure, each half undisturbed period of the control period corresponding to "1" (one) and each half period of disturbed corresponding to "0" (zero). These and other objects, features and advantages of the invention will be apparent from the following drawings, detailed description and annexed clauses. DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of an incorporation of a self-regulating inductor circuit that is part of a system for operating a lamp in accordance with the present invention.;
Fig. 2 shows the decoding mechanisms contained in the embodiment shown in Fig. 1; Fig. 3 shows an incorporation of the appropriate coding mechanisms for use with a self-regulating inductor as shown in Fig. 1, in a system for operating a lamp, according to the invention; Fig. 4 shows the silhouette of the signals that are present in the incorporation of a system that operates a lamp, as shown in Fig. 1, 2 and 3; and Fig. 5 shows a flow chart for controlling the operation of the coding mechanisms shown in Fig. 3. DETAILED DESCRIPTION OF THE INVENTION The fluorescent auto-regulator inductor circuit, shown in Fig. 1, includes a "A" filter buffer. triac and EMI, connected to a rectifier "B" of full bridge input, which together convert a sinusoidal AC power line voltage into a filtered DC voltage, rectified at an output thereof. The preconditioning circuit "C" includes circuits for the correction of active power factor, as well as to increase and control the DC voltage from rectifier circuit B, whose DC voltage is provided through a pair of rails RL1, RL2 DC. The self-regulating inductor circuit includes a DC-AC converter, or "E" inverter and a "G" controller that controls the inverter. The inverter "E" has a half bridge configuration that under the control of the half bridge controller, or actuator, the G circuit provides a high frequency lamp current coupled to the inverter E. In the embodiment shown in Fig. 1, the mechanisms I for generating a lamp current are formed by the filter "A", rectifier "B", pre-conditioning circuit "C" and inverter "E". The controller G forms the mechanisms II to control the operating characteristic (lamp output) of the lamp in dependence on the control signal. A regulating interface circuit "I" is connected between a rectifier circuit B output and a control input of the self-regulating inductor circuit present in the controller G, to control the regulation of the lamp. The regulator interface circuits provide a regulation voltage signal (the control signal) to the controller G and forms the decoding mechanisms to generate a signal depending on the silhouette of the control period. A detailed description of the operation of all parts of the self-regulating inductor circuit of Fig. 1, except for the decoding mechanisms, is provided in U.S. Application Ser. Serial No. 08 / 414,859 and will not be repeated here.
In the communication coded according to the invention, between the coding mechanisms and the decoding mechanisms of the incorporation of a system to operate a lamp shown in Fig. 1, 2 and 3, a selected number of line cycles or periods fundamental, form a period of control. The identification of the presence of a preset disturbance within the control period is indicative of a control command, for example, changing a lamp operating characteristic, such as the light level. The "presence identification" of the disturbance within the control period can simply be the number of times the disturbance occurs within the control period. The identification of presence can also be the pattern of locating the disturbance within the control period. For example, the disturbance can be coded to form a binary number within the control period. In an attractive embodiment for regulation, a first fixed number of disturbances represents a command to increase the light level, by means of a pre-selected amount of increase and a second different number of disturbances representing a command to decrease the level of light by the preselected amount of increase. A third number of cuts in the control period, represents the command to keep the light on the same level. Favorably, no (zero) cut per control period, represents the command to maintain a constant level of light. This has the advantage that when no change in light is desired, no disturbances are introduced into the waveform of the power line. Also, because no disturbances are introduced, there are no adverse effects on THD, power factor or component voltage. The disturbance is a phase cut in the nominal waveform of the fundamental periods, since this type of disturbance is easy to implement when controlling the triggering of the triac. Figures 4 (a) through 4 (c) represent the three waveforms of the energy line of a wall controller that forms the coding mechanisms that illustrate this particular regulation usage. The selected control period is three (3) full-line cycles in the coding mechanisms or in the wall controller, which are six (6) half-wave cycles after rectification in the interface circuit in the self-regulating ductor. Figure 4 (d) is a waveform on the receiver side, i.e. of the regulation interface, and is the differential of the energy line waveform of Figure 4 (c). If there is no requirement to change light intensity, the waveform of the power line will not be modified as shown in Figure 4 (a). In this way, no additional disturbance will be added within the line. In this case, there will be no pulse in the differential receiving waveform, - since the line voltage is a soft sine signal. A control signal to decrease light is represented by a phase cut in a positive side waveform during every three line cycles (Figure 4 (b)), which will result in an impulse in the receiving waveform after decoding (differentiation) by the receiver. A control signal to increase the light level is represented by two cuts in the control period (Figure 4 (c)) of such receiving waveform will have two pulses during every three line cycles, as illustrated in Fig. 4 (d). In the self-regulating inductor, the light will remain unchanged if no impulse is detected by the receiver in the rectified energy line waveform. If one or two pulses are detected, during each three line cycles (six cycles of medium waves after rectification), the light will change one step, i.e., by a preselected increment: in a corresponding direction. Experience shows that continuous regulation can be imitated if the number of steps between the lowest and highest levels is large enough, in other words, if the increase by which the light changes each time is very small. In the next addition, the number of steps is selected to be 100. If a rising or falling control signal is continuously generated by the wall controller, it will take 5 seconds for the light intensity change from the lowest level to the highest level. The main function of the wall controller or of the coding mechanisms for the coded regulation technique is to generate the control schemes illustrated in Figures 4 (a) - 4 (c). The circuit diagram of an appropriate transmitter, in the form of a wall controller, is shown in Figure 3. Lo: .3 input terminals I and 3 are for the connection of the white (neutral) and black (active) lines ) of the power line, respectively. The output terminal 2 connects to the red output line that carries the coded active AC signal to the self-regulating inductor. A triac U1 is connected between terminals W1 and W2. A downstream transformer WT1 has each end of its primary winding WP1 connected to one of the respective terminals W1 and 3. The ends of the secondary winding WSl are connected to the nodes W4, W5 respective of a complete bridge rectifier formed by diodes WD1-WD4. The cathodes of the diodes WD1 and WD2 are connected to the node W4 and the anodes of the diodes WD3 and WD4 are connected to the node W5. The cathode of the diode WD3 and the anode of the diode WD1 are connected to the node W6 and the cathode of the diode WD4 and the anode of the diode WD2 are connected to the node W7. The triggering of the WU1 triac is controlled by an 8-bit ICI microcontroller with a generation oscillator. An appropriate driver for ICI is the Motorola MC68HC05kl, The ICI microcontroller has two ports, A, B. Port A has eight terminals and port B has two terminals. There are four push button switches WS1 - WS4 to control the following functions: on, off, increase in light, decrease in light. The microcontroller IC-1 reads the status of these switches through its terminals PA4-PA7 of port A. The node W7 of the rectifier is connected to the terminal 1 1 of power supply VDD through the line V \ RL2 including a WU2 regulator with a voltage of 5V. An electrolytic capacitor WC1 is connected between the lines WRL3 and WRL2 on the input side (A) of the controller WU2 to filter the DC ripple of the rectifier. A capacitor WC2 is connected between these same lines on the output side (B) of the regulator W2 to filter the noise. The WD5 zener diode makes a bridge to the WRL3 and
WRL5, with, 3u > cathode connected to the last line. The termi nals RST '(reset) and IRQ (interrupt request) «are also connected to the WU2 output regulator of + 5V. A ceramic XT resonator is connected through oscillator terminals 0SC1 and 0SC2, with components WC3, WC4 and WR2 that are specified by the resonator manufacturer to ensure proper operation of the XT re-sonator. The ICI microcontroller needs a signal crossed at zero line voltage as a reference to trigger the triac WU1. This signal is provided by resistor WR1 and diode WD5 zener, and is input to terminals PBO and PBl. Because the voltage at the cathode of the WD5 diode is only 4.7V, which is much less than the peak power line voltage, it provides a logic "1" and "0" signal at the PBO and PBl terminals, when The line voltage crosses zero. The ICI controller sends out a d: .spam signal immediately after the zero crossing of the line voltage is detected, there is no modification to the waveform of the power line. This provides the waveform of Fig. 4 (a) for a constant light level. To provide a phase cut in any one or both of the half cycles to generate the signals to increase or decrease the light level (as shown in Figures 4 (b) and 4 (c)), the signal Trigger is delayed about 1.39ms after zero crossing for each respective half cycle. This provides a small phase cut of about 30 degrees.
Figure 5 is a program flow diagram for the wall controller. After starting the port addresses, the program enters into a loop that reads the esteido of the four switches WS1-WS4. If a switch is activated, the program will execute the corresponding function. For example, when the WS4 switch (keyed) is pressed, the wall controller will produce the waveform of Fig. 4 (b) to regulate the light and when the WS3 switch (without key) is pressed, the will ducirá the waveform of Fig. 4 (c), to increase the level of light. When the WS1 switch (low key) is pressed, the power will be supplied to the connected lamp driver, without any disturbance imposed on the AC power line signal. When the switch WS2 is pressed, the AC power line signal is completely interrupted so that power is not supplied to the connected auto-regulator inductor. Figure 2 is a diagram of the decoding mechanisms or receivers, or the interface circuit, in the self-regulating inductor circuit. The core of the interface circuit is the microcontroller IC2 (for example, a Z86G04 from Zilog, Inc.), which converts the control control signals into a corresponding output of PWM (Pulse Width Modulation). The microcontroller IC2 has P31 inputs that accept the coded control signals. The output PWM signal (regulator) is formed in terminal P27 and becomes a signal present in terminal Z7 to enter the "regulator" input of controller "G" in the half-bridge actuator to adjust the power of the controller. lamp. Node A (also referred to as Z8) of rectifier circuit B is connected to ground (ref Z9) through a voltage divider network work consisting of resistors GR1, GR2 and GR3. The input P31 is connected to a node B through the differential circuit formed by GC2 and GR5. A parallel zener GC6 diode connects with GR5 to protect the input of the IC2 receiver. The microcontroller is operated in the VCC terminal with a 5V voltage source, in this case a voltage regulator U3. An external ceramic XL1 resonator (2MHZ) is connected between the clock terminals XI and X2. The clock terminals are connected to ground through capacitors GC3 and GC4, respectively, to ensure proper operation of the resonator. Capacitor GC5 is connected enters the ground and supplying the voltage to suppress the noise. The GR6 resistors, GR7 and the capacitors GC6 and GC7 soften the PWM output signal from the P27 terminal to an average DC signal to enter the regulator input of the G controller. When the power is turned on, i.e. the main voltage of the wall controller is provided to the input terminals 1 ', 2' of the self-regulating inductor, the microcontroller IC2 is started and the output P27 is set to a PWM value of missing light level, for example 85% of the light output. The input threshold level of the microcontroller is about 2.5V. This means that it is logical "1" if the input is close to 2.5V and logical "0" if the input is less than 2.5V. The differential circuit provides a pulse to the terminal P31 greater than 2.5V ("1" logical) when the half sine-wave cycle includes a phase cut with the coded regulator (Fig. 4 (d)). The rectified DC output that is fed to the interface circuit is 120Hz of DC pulses. If a normal ON / OFF wall switch is installed in place of a regulation control device, the output PWM signal is set to a fault level, because the power line remains unchanged and the microcontroller U2 does not it will detect no impulse as it is entered. The microprocessor IC2 includes an 8-bit register called PWM which controls the output signal PWM in the form of a substantially square wave, present in the output of the PWM register to P27. Programmer 0 in the microcontroller determines the duration of th (the time interval during which the output PWM signal is high) and th (time interval during which the output signal is low) based on the PWM value in register. After timer 0 counts the time, an interrupt 4 will be generated. In the interrupt subroutine, the first test is to the output status of the current PWM register. If the output of the current PWM register is logical "0", then it adjusts the output of the PWM register to l and installs the PWM value inside the programmer 0. If the output of the current PWM register is logical "1". The PWM record output is set to logical "0" and installed (255-pwm) within programmer 0. The time to invoke the next interrupt is proportional to the value installed within programmer 0. The time of t plus tL is adjusted to be independent of the PWM value so that the PWM signal frequency is constant. In this way, with a higher PWM value, the PWM register has more time to remain in a logical "1" and provides an average regulation output control voltage in the pin 27. The regulation control voltage limit it is adjusted from 0.4V to 3V which means that the service PWM cycle should be from 8% to 60%, because logical "0" is zero volts and logical "1" is 5 volts. A pulse on terminal P31 invokes an interrupt subroutine 1. "The procedure of" interrupt 1"increases the value of a register called" im-pulse number "by 1. The control loop (CDL) of regulation The installed code in the microcontroller IC2 checks the value of the record "pulse number" every 50ms, because 50ms equals 3 line cycles, the value of the record "pulse number" will determine if the light level should change. the value in the register "impulse number" equals zero (0), there is no impulse, so there is no change in the light level or the PWM value when the "impulse number" register equals to one (1), the PWM value is decreased until it reaches the preset minimum value.When the record "impulse number" equals two (2), the PWM increases until it reaches a preset maximum value. , the interface circuit allows the self-regulating inductor to automatically accept the regulation inputs from the wall controller and produce a DC signal, input to the controller G to control the light level of the fluorescent lamps. Under non-regulatory conditions, the self-regulating inductor maintains an energy factor >; 0.99, THD < 10%, and a crest factor < 1.6, for the circuit to satisfy both the need for a self regulating regulating inductor while also providing a high energy factor and maintaining THD, EMI and very low component voltages even at the lowest regulation levels.