Abstract: There is provided an integrated electric compressor that can be made small in size while reducing radio noise effectively. In an inverter of the electric compressor, a snubber circuit 21 comprising a resistor R and a capacitor C is provided between input/output terminals 20 of a power source and a switching element 18. The snubber circuit 21 is formed by surface mounting a resistive element constituting the resistor R and a capacitor element constituting the capacitor C on a power board 16. A leakage current from a motor 19 is thus restrained and radio noise is reduced. The resistive element and the capacitor element constituting the snubber circuit 21 are preferably surface mounted on the power board 16 on the side opposite to the side on which a control circuit board is arranged.

Abstract: An electronic circuit is disclosed for dividing the frequency of a periodic signal, wherein at least one of the memory elements is arranged with its output terminal connected to the input terminal of another memory element wherein the electronic circuit is configured to generate an output signal having a smaller fundamental frequency than the clock signal at at least one of the output terminals. Each memory element is configured to change and hold a voltage at the output terminal based on a voltage at the input terminal at times controlled by a clock signal received at the clock terminal. At least two of the memory elements are stacked in the sense that the bottom terminal of a first memory element is connected to the top terminal of a second memory element to enable the charge to flow from the first memory element to the second memory element.

Abstract: A voltage source inverter comprises a rectifier converting AC power to DC power at an output. An inverter receives DC power and converts the DC power to AC power. A link circuit is connected between the rectifier circuit and the inverter circuit and comprises a DC bus. A DC bus capacitor across the DC bus smoothes voltage ripple. An active filter circuit comprises a pair of filter capacitors in series across the first and second rails to create a midpoint. Bidirectional switches are connected between the rectifier input and the midpoint. A current sensor is connected between the bidirectional switches and the midpoint. An active switch controller controls a conduction angle of the bidirectional switches to maintain DC bus voltage at a desired reference level under a wide load range.

Abstract: A power supply for a load control device generates a DC voltage and provides an asymmetrical output current, while drawing a substantially symmetrical input current. The power supply comprises a controllably conductive switching circuit for controllably charging an energy storage capacitor across which the DC voltage is produced. The energy storage capacitor begins charging at the beginning of a half-cycle and stops charging after a charging time in response to the magnitude of the DC voltage and the amount of time that the energy storage capacitor has been charging during the present half-cycle. The charging time is maintained substantially constant from one half-cycle to the next. The power supply is particularly beneficial for preventing asymmetrical current from flowing in a multiple location load control system having a master load control device supplying power to a plurality of remote load control devices all located on either the line-side or the load-side of the system.

Abstract: A bias voltage is compared with a voltage difference in a detecting element according to the present invention. A bias voltage unit is coupled to the detecting element, so that they have a common voltage level to avoid noises when the circuit is operating. Accordingly, the erroneous detection caused by the noise interference can be avoided. Hence, a detecting element with a low resistance, such as an MOEFET, can be used in the present invention to decrease power consumption arisen from current detection and to further increase conversion efficiency.

Abstract: A power supply includes a direct current (DC) voltage converter, a display, a voltage output interface, and a main controller. The DC voltage converter is connected to a voltage terminal of a peripheral interface. The display displays an input interface to allow a voltage value to be inputted therein. The main controller includes a voltage obtaining module and a control module. The voltage obtaining module is used to obtain the inputted voltage value, and output the inputted voltage value. The control module is used to output a pulse width modulation (PWM) signal to the DC voltage converter according to a proportion relationship between the inputted voltage value and the value of a predetermined voltage value. The DC voltage converter is used to convert the first voltage into a second voltage according to the PWM signal, and outputs the second voltage through the voltage output interface.

Abstract: A controller and methodology for a power supply are disclosed. The controller includes output channels for providing a pulse width modulation (PWM) voltage signal for driving a load, for example, a microprocessor. Each channel provides a portion of the PWM signal. The controller receives user input information and uses that information to automatically determine window sizes. A window size defines the maximum output current level for a given window. The controller uses feedback signals to determine the current being drawn by the load, and selects the number of windows and channels that are needed to adequately provide that current. The controller selectively activates and deactivates the output channels accordingly. In response a change in the user input information the controller automatically adjusts the window sizes.

Abstract: A motherboard with overclocking and overvolting functions is provided. The motherboard with an overvolting function includes a specified component, a voltage regulator and a micro-controller. The specified component receives an operating voltage. The voltage regulator generates the operating voltage according to a reference voltage. The micro-controller is electrically connected to an external input device for receiving a control signal issued by the external input device and adjusting the reference voltage according to the control signal.

Abstract: A power circuit includes a reference potential circuit, a step-up circuit, and a conversion circuit. The reference potential circuit generates a reference potential. The step-up circuit generates a desired internal potential by stepping up a power supply potential. The step-up circuit includes a comparison circuit, a differential amplifier circuit, and a switch element. The comparison circuit outputs the result of comparison between a potential and the reference potential. The differential amplifier circuit is turned on or off by the operation control signal. The switch element performs on/off control according to the operation control signal and resets the output potential of the differential amplifier circuit. The conversion circuit converts the of the operation control signal so as to make longer the on period of the differential amplifier circuit and the off period of switch element.

Abstract: A LED display system includes multiple LEDs, a power converter to produce a supply voltage for the LEDs, and multiple drivers to drive the LEDs. According to the maximum one of the forward voltages of the LEDs, the drivers provides a feedback signal for the supply voltage control, and the feedback signal is amplified or digitized to reduce the voltage drop in the global power line.

Abstract: The present invention relates to a digitally controlled switched-mode power supply, wherein a switched-mode power supply is provided with a control circuit, which comprises a signal amplifier unit able to receive digital signals or analog signals and a switching controller able to receive the signals. The switching controller uses the signals to produce a clock signal, after which the clock signal is output, whereupon the signal amplifier unit feeds a signal back to control the switching controller. The signal amplifier unit is provided with at least one amplifier element, and when the amplifier element receives a digital signal or analog signal, then the signal is transmitted to the switching controller. Accordingly, the control circuit achieves the effectiveness to not only receive and transmit digital signals, but also receive and transmit analog signals, and is thus provided with the advantage of enormous flexibility.

Abstract: A method and apparatus for providing a selected amount of power from a power source to a load produce a pseudo random code sequence of different type bits, in which one type of the different type bits is used to control application of power from the source to the load so that the power applied to the load corresponds to the total of the number of the bits of one type applied to the load in a given time period. A plurality of code sequences is provided, with each corresponding to a different power level, and a sequence can be selected to provide a selected power level to the load.

Abstract: One embodiment of the invention includes a switching power supply system. The system includes a switch network comprising at least one switch configured to provide an output voltage based on switching activity thereof. The system also includes a switching controller configured to control the switch network to maintain the output voltage provided at an output based on a feedback signal associated with the output voltage. A converter pulse detector is configured to detect an output voltage overshoot condition based on the switching activity of the switch network corresponding to a transition in an output load to which the output voltage is provided.

Abstract: A control system for dynamically adjusting an output voltage of a voltage converter includes a signal calculation circuit, a pulse width modulator, a voltage converter, a nonlinear calibration circuit and a signal converter. The signal calculation circuit, the pulse width modulator, the voltage converter and the signal converter form a long-tail loop. The signal calculation circuit simultaneously receives a target value and a detection value from the signal converter to generate an error value for adjusting the output of the pulse width modulator. The voltage converter and the nonlinear calibration circuit form a local pulse-squashing loop. Pulse widths of an input signal to the voltage converter can be timely and effectively calibrated and controlled, thereby decreasing power consumption of the voltage converter and providing an effective protective mechanism.

Abstract: Certain embodiments of the invention may include systems and methods for controlling power in renewable solar energy sources. According to an example embodiment of the invention, a method is provided for controlling a renewable energy solar farm, where the farm may include one or more renewable energy sources. The method may include measuring aggregate energy output of the renewable energy solar farm and measuring individual source energy output of the one or more renewable energy sources. The method may also include controlling energy production from the one or more renewable energy sources via a controller based at least in part on the measured aggregate energy output and the measured individual source energy output, where the controller facilitates communications with the one or more renewable energy sources.

Abstract: A tuner having one or more digitally controllable tuning components may be coupled to an analog feedback compensation network in a target switching power supply controller to adjust the compensation while the power supply is operating. A communication interface couples the tuner to a host having a software interface to enable a user to adjust the values of the tuning components. The tuner may include components to adjust the values of a feedback network, an input network, a ramp adjust component, etc., on the target controller.

Abstract: A system and method are disclosed for controlling a regulator circuit that outputs a plurality of radio frequency power amplifier bias voltages. A feedback loop is connected to the regulator circuit from the plurality of bias voltages that are output from the regulator circuit. The feedback loop comprises a demultiplexer circuit and a multiplexer circuit that are connected to the regulator circuit. The demultiplexer circuit and the multiplexer circuit each receive an enable signal and provide a feedback signal to the regulator circuit from the bias voltage that is associated with the received enable signal. The invention allows the regulator circuit to be configured as needed to provide different values of radio frequency power amplifier bias voltages.

Abstract: An apparatus to generate a high voltage includes an outputting part having a power transforming part formed with a primary and a secondary coil, a switching part to control an output voltage induced in the secondary coil of the power transforming part, by interrupting a current in the primary coil of the power transforming part, a digital controlling part to control an interruption operation of the switching part according to a time constant determining a wave form of the output voltage of the power transforming part and a control reference value determining a level of the output voltage, and a digital interfacing part to convert input control data having first and second forms into the time constant and the control reference value, respectively, and to provide the time constant and the control reference value to the digital controlling part.

Abstract: A load control device is adapted to be installed in an electrical wallbox having a barrier. The load control device comprises a split enclosure having first and second enclosure portions spaced apart so as to define a gap, such that the gap is adapted to receive the barrier of the electrical wallbox when the load control device is installed in the wallbox. First and second connectors are provided in first and second openings of the first and second enclosure portions, respectively. The load control device is operable to receive a first control signal at the first connector and to generate a second control signal, which is provided at the second connector, in response to the first control signal.

Abstract: A system for analyzing the operation of a switching power converter includes a digital controller for receiving an analog signal representing the output DC voltage of the power converter for comparison to a desired output voltage level and generating switching control signals to control the operation of the power supply to regulate the output DC voltage to said output voltage level. At least one portion of a control loop within the digital controller may be switched into the control loop in a first mode of operation and out of the control loop in a second mode of operation. A microcontroller emulates the operation of the at least one portion of the control loop during the second mode of operation.

Abstract: In a semiconductor device for generating complementary PWM signals for, for example, controlling an inverter, a dead time is flexibly added by using a simple architecture. A dead time addition unit adds time elapsing until a value of a timer reaches a set value of a register as a first dead time at a rise of a first PWM signal. On the other hand, time elapsing until the value of the timer reaches a set value of another register is added as a second dead time at a rise of a second PWM signal.

Abstract: A method for controlling a power supply, the method comprising: forming a front-end to the power supply, the front-end comprising a plurality of digital-to-analog circuits under control of a controller; and programming the controller to control the digital-to-analog circuits to send a user-defined output reference voltage and a user-defined over voltage protection reference voltage to the power supply.

Abstract: A phase-control power controller that converts a line voltage to an RMS load voltage includes an analog load voltage sensor that includes a light emitter that provides an optical output related to an RMS load voltage, and a phase-control circuit that has a comparison circuit that varies a resistance in the phase-control circuit responsive to the optical output. The comparison circuit includes an optically coupled transistor that senses the optical output from the light emitter, a load sensitive resistor that emits an amount of thermal energy corresponding to an amount of optical energy sensed by the optically coupled transistor, and two thermally dependent resistors connected in series, where one of the two resistors has a resistance that corresponds to the amount of thermal energy emitted by the load sensitive resistor and that varies the resistance in the phase-controlled dimming circuit.

Abstract: A phase-control power controller that converts a line voltage to an RMS load voltage includes a phase-control circuit with a potentiometer and a capacitor whose resistance and capacitance determine clipping of a load voltage, a load sensing circuit that senses the load voltage and provides a DC signal that is different from but related to the RMS load voltage, and a comparator circuit that compares the DC signal to a reference and adjusts the resistance of the potentiometer to control the RMS load voltage.

Abstract: A digital signal to pulse converter including a spectral spreader which provides an adjusted clock signal that does not cycle during selected cycles. The adjusted clock signal is written into a multi-port content addressable memory which, as a function of the current count, provides output signals that determine a beginning or an end of a pulse within a frame. The spectral spreader varies the number of selected cycles to adjust the frame rate as desired, linearly or nonlinearly.

Abstract: A control structure and method for controlling a sensor heater including a power supply connected to a switching device for pulse width modulating a voltage from the power supply. The switching device is further connected to a resistance heater. A microcontroller having a single output is connected to the switching device and a single input from the microcontroller is connected to a high side of the resistance heater. The microcontroller determines a pulse width modulation duty cycle to maintain a constant power dissipation of the resistance heater.

Abstract: A digital dynamic trace adjustment pulse width modulate controller uses a core processing unit to receive a phase signal and outputs a pulse width modulate signal. It is observed that when the output voltage is rising or dropping then changing the pulse width modulate signal of the output end, the duty rate of the phase signal will be maintained at fifty percent degree.

Abstract: Improvements to lighting systems, especially for entertainment and architectural applications are disclosed, including apparatus that permit a user to readily field-configure power distribution to branch circuits to be dimmed or un-dimmed, single- or multi-phase, as required; communication of data over existing power wiring by variations in output of dimmers; and improved methods for generating, managing, and distributing data specifying the physical and electrical configurations of a lighting system.

Abstract: A genset controller that is configurable for controlling a variety of types of gensets, as well as a method of configuring a genset controller for controlling a genset, are disclosed. The genset controller includes a memory for storing a plurality of software routines, a personality profile data set, and a user-settable data set, and further includes a processor coupled to the memory for executing the software routines and reading data from the personality profile data set and the user settable data set to control the genset. The genset controller additionally includes an input port coupled to the memory for enabling changes to the personality profile data set and the user-settable data set to be downloaded into the memory. The personality profile data set and the user-settable data set include data that configures the genset controller for operation with a particular genset.

Abstract: In order to implement a method of graduating the dissipation of an alternating electrical power signal, provision is made to place the position (Reg3) of a period of the alternating signal in correspondence with the binary inverse (Reg4) of a digitized set-point parameter. It is shown that, in this way, the periods of dissipation are ideally distributed among the periods of non-dissipation. This has the principal effect of reducing the effects of blinking which are particularly undesirable when the rise time of the phenomenon to be controlled is short as regards the period of the alternating electrical signal.

Abstract: A digital phase-locked loop (DPLL) (22) for use in one or more integrated circuits (20) that may be combined within an electronic system is disclosed. The DPLL (22) includes a phase detector (30) that generates a shift clock and a shift direction signal responsive to a phase difference between a system clock and a feedback clock. The shift direction signal is stored in a latch (32), applied to one input of an exclusive-NOR gate (34), and to shift direction inputs (R/{overscore (L)}) of first and second digital delay lines (38, 42). The first digital delay line (38) receives the system clock and generates a delayed clock that is distributed within the integrated circuit (20) by clock distribution circuitry, and that is applied to an input of the second digital delay line (42); the second digital delay line (42) generates the feedback clock that is received by the phase detector (30).

Abstract: Improvements to lighting systems, especially for entertainment and architectural applications are disclosed, including apparatus that permit a user to readily field-configure power distribution to branch circuits to be dimmed or un-dimmed, single- or multi-phase, as required; communication of data over existing power wiring by variations in output of dimmers; and improved methods for generating, managing, and distributing data specifying the physical and electrical configurations of a lighting system.

Abstract: Apparatus and methods for AC power regulation primarily intended for inductive loads (e.g., fluorescent lights, motors, etc.) which provide substantial reduction in power consumption while also providing a leading power factor, reduced harmonic distortion, reduced crest factor and reduced noise. The system is self-adjusting for a wide range of loads and can reduce power consumption by 25 percent in lighting loads while producing minimal reduction in light output. The system utilizes a Triac and parallel capacitor bank in series with the load. The Triac is turned on in response to a near-zero differential voltage measured across the Triac and is turned off near the peak of each AC half cycle by shunting current around the Triac. The capacitor absorbs the inductive turn-off voltage spike caused by the collapsing magnetic field in the ballast at the instant of Triac turn-off. This energy, in turn, provides longer on-period for the lamp, thereby permitting more light and increased operating efficiency.

Abstract: A communications processor is disclosed for a power generation system that permits data and control signals to be communicated to and from the power generation system and a host computer. The control signals include a power level command and power factor that are sent from a remote host to the power generation system which responds by delivering the requested power level having the desired power factor to a grid. The remote host receives performance data that permits an operator to accurately gauge the performance of the power generation system including the performance and any fault conditions of a line power unit, generator, and engine driving the generator. The communications processor unburdens the line power unit controller that is responsible for controlling power generation from the task of processing input data and driving local displays. The host may also be provided at a location remote from the power generation system.

Abstract: A method for the low-transient power control of electrical loads, particularly temperature-dependent loads electrically divided into essentially equal sub-loads connectable to an a.c. mains in order to receive power. Power control at low power levels utilizes alternately power-off phases, in which none of the sub-loads receive power for at least three a.c. half-waves, and heating phases, in which a temporal concatenation of at least a first and a second basic cycle of three a.c. half-waves supply power to each one of the sub-loads. The first sub-load receives power during one half-wave of the first basic cycle and the second sub-load receives power during one half-wave of the second basic cycle. The power is turned off during the other two half-waves of the first and the second basic cycle. Also disclosed is an electrical heating apparatus which embodies this method.

Abstract: A method for controlling the power of a load (1) powered from a source of AC voltage U having a period T using a phase control system, wherein, for a predetermined set power, a sequence of an integer p of elements, where p is greater than 1, is periodically delivered to the load (1), each element, numbered i, of the sequence being characterized by an integer n.sub.i with a half-period T/2 during which the AC voltage U is switched according to a series of different phase angles .alpha..sub.i from .alpha..sub.1 to .alpha..sub.n corresponding to respective durations t.sub.i from t.sub.l to t.sub.n during which the load (1) is cut: off from the power supply. The phase angles .alpha..sub.i of element i and .alpha..sub.i+1 of element i+1 have similar repetitive values so that the mean current is zero over a complete cycle.

Abstract: A duty cycle based AC power control method reduces objectionable voltage fluctuations at a frequency that causes "flicker" by shifting the frequency of actuations of controlled devices to frequencies significantly greater than and/or less than the flicker sensitive frequency. The frequency of actuations may be redistributed (1) by segmenting the devices to provide approximately equal power requirements per actuation, (2) by providing one-half cycle actuation pulses rather than one cycle actuation pulses, and/or (3) by spacing the actuations evenly over a given time period and forcing the aggregate demand to follow a slowly rising/falling envelope. The result is the minimization of power distribution at the flicker frequency.

Abstract: An energy control system (10) comprises at least one controllable load (110), a master controller (200), a traveler wire (300) and at least one remote switch (400). The master controller (200) transmits control commands that effect corresponding control actions in the controllable load (110). The remote switch (400) transmits remote commands to the master controller (200) over the traveler wire (300). The energy control system (10) is well suited for installation in standard three-way switch or four-way switch electrical systems and requires neither additional wiring nor complicated installation procedures.

Abstract: A system for controlling an Alternating Current (AC) signal to an AC powered device. The system uses a microcontroller to monitor the cycles of the AC signal supplied to the AC powered device. By utilizing cycle counting, the microcontroller can supply various numbers of waveforms to the AC powered device in order to adjust the speed and/or energy supply level to the AC powered device. At full power, all the cycles of the AC signal are provided to the AC powered device. If the speed and/or energy supply level of the AC powered device needs to be reduced by half, the microcontroller supplies every other cycle of the AC signal to the AC powered device.

Abstract: A controller for a voltage regulator has an input keypad for designating selected operating parameters of the voltage regulator. The keypad is formed with a dedicated function portion and a menu navigation portion, and the parameters are divided into first and second categories. The controller has a display for displaying the parameters, and a computer is connected to the input and to the display for controlling the display in response to activation of the keypad. Any parameter in the first category can be displayed on the display by activation of the dedicated function portion of the keypad. Any parameter in the second category can be displayed by activation of the menu navigation portion. The menu navigation portion can optionally also be used to control display of parameters in the first category.

Abstract: A lighting system made up of a plurality of light fixtures which each produce a light beam, in which each of a plurality of varying devices, each having an input and an output, and each capable of varying at least one parameter of the light beam from at least one of the light fixtures, is responsive to a first value received at the input, where the first value corresponds to the desired adjustment of a parameter of the light beam. Each of the varying devices is also capable of generating a second value which represents status information, and transmitting the second value via the output. A controller produces the first value and sends it to an output which is coupled to the input of the varying device. A monitoring device has an input and is separate from the controller, and its input is coupled to the output of the varying device.

Abstract: A method for controlling the power supplied to a load (1) which is powered by an AC voltage source U with a period T via a generalised phase adjustment system, includes the steps of periodically delivering a sequence of p elements to the load (1), in accordance with a predetermined set power, wherein p is an integer and each element comprises n.sub.i periods T, where n.sub.i is an integer, during which the voltage U is divided symmetrically at an angle .alpha..sub.i, the consecutive phase angles .alpha..sub.i and .alpha..sub.i+1 being different, and the combination of angles .alpha..sub.1 . . . .alpha..sub.i , . . . .alpha..sub.p being selected in such a way that they limit current harmonics, and limit a flicker effect. The method is particularly suitable for power control in electric motors.

Abstract: A technique for powering telephone lines using an unbalance current source and current sink; and a technique for improving attenuation/frequency distribution and return loss (impedance matching) of transformer-coupled wire-line communications circuits by using secondary series capacitance and an AC current pump signal source; and a generation of ringing voltage as positive voltage pulses with respect to a negative power supply voltage; and a technique for removal of AC power ripple by using an active linear floating filter for the purpose of powering telephone line circuits, and a technique for injection of real time tone samples into T1 transmissions circuits by use of a T1 framer idle code register.

Abstract: An optically controlled dimmer type device which can be used to regulate the brightness of an incandescent lamp. The device can also be used to control other electrical loads such as a.c. type motors. One of the main characteristic of the device is that it is adapted to be optically controlled. The device includes a light emitting component adapted to emit light and a light receiving component positioned to receive the light reflected by an object from the light emitting component and to thereby generate an output signal. A processing circuit including a phase shift circuit is operatively associated to the light receiving component. The processing circuit is adapted to receive the ouput signal and process the output signal and thereby regulate power output to the electrical load.

Abstract: Apparatus and methods for AC power regulation primarily intended for inductive loads (e.g., fluorescent lights, motors, etc.) which provide substantial reduction in power consumption while also providing a leading power factor, reduced harmonic distortion, reduced crest factor and reduced noise. The system is self-adjusting for a wide range of loads and can reduce power consumption by 25 percent in lighting loads while producing minimal reduction in light output. The system utilizes a Triac (32) and parallel capacitor bank (58) with the load (22). The Triac (32) is turned on in response to a near-zero differential voltage measured across the Triac (32) and is turned off near the peak of each AC half cycle by shunting current around the Triac (32). The capacitor (60) absorbs the inductive turn-off voltage spike caused by the collapsing magnetic field in the ballast at the instant of Triac turn-off.

Abstract: A light dimmer is provided in which semiconductor power devices for each of the polarities of an alternating current supply are coupled between the alternating current supply and a lamp load. In the course of varying average power supplied to the lamp load, the semiconductor power devices transition between an initial one and a subsequent other of substantially conductive and non-conductive power conditions. The duration of the transition by the power device is increased beyond the minimum possible duration to reduce generated EMI. Methods of restoring each power device to its initial condition, including during a subsequent half-cycle, are described.

Abstract: Apparatus and methods for AC power regulation primarily intended for inductive loads (e.g., fluorescent lights, motors, etc.) which provides substantial reduction in power consumption while also providing a leading power factor, reduced harmonic distortion, reduced crest factor and reduced noise. The system is self-adjusting for a wide range of loads and can reduce power consumption by 25% in lighting loads while producing minimal reduction in light output. The system utilizes a triac and parallel capacitor bank in series with the load. The triac is turned-on in response to a near-zero differential voltage measured across the Triac and is turned-off near the peak of each AC half cycle by shunting current around the Triac. The capacitor absorbs the inductive turn-off voltage spike caused by the collapsing magnetic field in the ballast at the instant of triac turn-off. This energy in turn provides longer on period for the lamp, thereby permitting more light and increased operating efficiency.

Abstract: This present invention takes advantage of the understanding that the voltage rating associated with resistive heating element can be ignored over the common line voltage range, provided the power dissipation is controlled. This is accomplished by applying a fractional amount of power to a heating element from the power source. The method consists basically of determining, or estimating, a ratio of the amount to be applied to the amount of power available. A control signal is generated with a duty cycle approximately equal to that ratio. A zero crossing switch, under control of the control signal switches half cycles to the heating element. Thus, by applying a portion of the available half cycles to the heating element, the average power dissipation by the heating element can be controlled.

Abstract: A low voltage dimmer is shown with the dimming function being on a primary side of a low voltage transformer. Live voltage feeds through a triac to the primary side of the transformer with the gate for the triac being controlled by a microprocessor. To prevent burnout of the transformer if the secondary load side is open, zero crossing of the incoming signal is determined by the microprocessor. If the time constant between the zero crossing of the live voltage and the charging of a capacitor with resistance being provided by the primary side of the transformer exceeds w predetermined time period, the microprocessor will be inhibited from generating a pulse to fire the triac. When the primary side of the transformer has been opened, the load on the secondary side can be re-established, i.e. light bulb replaced. Power for the microprocessor is from the charging of a capacitor used to provide the triggering signal to the microprocessor. Also the microprocessor may be triggered from remote locations.

Abstract: A heating element operating unit, control device therefor and methods of making the same are provided, the control device being adapted to operate a heating element that comprises a hot surface igniter with a certain repeating pattern of a single complete half-wave pulse in each repeating pattern of at least two complete full-wave pulses of a source of high voltage alternating current for a predetermined time period, the control device utilizing a staircase generator of two transistors for operating the heating element.