Abstract: An alternator circuit for alternately operating one of first and second electrical load devices which uses a magnetic latch relay to perform the alternation. The circuit includes a first circuit means for supplying electrical energy from a source to one of said first and second electrical load devices, and magnetic latch relay alternating means having first and second states. The alternating means in a first state interconnects the first electrical load device to the first circuit means, and in the second state interconnects the second electrical load device to the first circuit means. One application of the inventive circuit is for use in controlling the level of liquid in a container within a predetermined range using 2 pumps.

Abstract: A control apparatus controls power supply to a first load which generates a higher counterelectromotive force upon interruption of power supply and a second load which generates a lower counterelectromotive force upon interruption of power supply. The control apparatus includes a CPU of a facsimile machine for example. Before interrupting power supply to the first load, the CPU determines whether or not the second load is under power supply. When the second load is determined to be under power supply, the CPU immediately interrupts power supply to the first load. When the second load is determined not to be under power supply, the CPU first starts power supply to the second load and subsequently interrupts power supply to the first load.

Abstract: A power supply circuit is provided with a supplemental power source which is intermittently brought into service each time a main power source is coupled to a high power drain circuit. That is, the supplemental power source is switched to a circuit, which is susceptible to power drop, in response to switching over of the main power source to the high power drain circuit.

Abstract: A basic circuit (10) includes an oscillator (11) whose frequency can be set via a frequency-determining component (15). At outputs (A1-A5), the basic circuit (10) cyclically generates pulses by which consumers (L1-L5) are driven. A switch (18) is connected in parallel to the frequency-determining component (15), said switch being controlled by the outputs (A1-A5) and changing the oscillator frequency during an output pulse. Thus, the output pulses change the oscillator frequency and thus their own pulse duration themselves.

Abstract: A power sharing device is disclosed, having a primary utility in supplying power to automotive block heaters or other auto warming devices at a user selectable duty cycle of 12.5% or 25%. In a first mode, power is supplied to 4 outlets in a sequential manner, for 15 minutes each. In a second mode, power is supplied to the 4 outlets in a sequential manner, for 7.5 minutes each, followed by a period of 7.5 minutes in which power is not supplied. The user may elect to initiate a delay period, that is selectable between 1 and 2 hours, to precede the sequence of power distribution, allowing time for the car to cool before the power cycles begin. A test circuit, activated by a pushbutton, allows a user to distinguish between the periods of time when power is not being supplied to an outlet as a part of the sequential sharing of power between outlets and a circuit malfunction, such as a blown fuse.

Abstract: A system that monitors and controls electrical power consumption that will be retrofitted to a typical consumer electrical power arrangement (typical arrangement-electrical feed line from a provider, a meter, a circuit breaker and individual input wiring to a plurality of electrical devices, appliances and outlets). The system includes a control unit which receives information from an electromagnetic pickup device from which real time electrical consumption is determined over very short periods of time. The control unit has a main data processing and storage processor for retaining information and it may include a communication microprocessor for sending signals to corresponding modules. The electromagnetic pickup device uniquely measures the electromagnetic flux emanating at each output wire from each of the individual circuit breakers in a breaker box. The modules have filters which release electrical power to the individual electrical devices, appliances and outlets at a controlled, economic rate.

Abstract: In a distributor, a plurality of switches are connected in series with one another on main distribution lines emerging from a receiver switching apparatus, thus forming a trunk. A branch line extends from a junction between each pair of adjoining switches and leads to each load via another switch and a transformer, wherein each pair of switches on the trunk is formed as a single branch unit, and the switch and transformer are united as a power package. In each power package, a supply bushing and a load bushing are placed on the top of a transformer, and shielded with closed housings. A switch is placed in the closed housing for the supply bushing, and a distribution board is placed in the closed housing for the transformer. This configuration enables the disconnection of any branch distribution lines from the main distribution lines and diminishes the installation space.

Abstract: An automatic addressing scheme for a life safety system having a local rail, and a plurality of modules inter-connected by the local rail, a first of the modules being a central processing unit, and the remainder being I/O modules having a variety of functions, as well as a common line forming part of the local rail; an arrangement is provided for detecting the location of each of the I/O modules and assigning addresses thereto without human intervention, the arrangement including a resistor and transistor, capable of being conductive to ground, associated with each I/O module. A constant current source is located at the central processing unit, connected by the common line to the resistors in series circuit, and with a common address input means connected from the central processing unit to said common line and thereby to the I/O modules.

Abstract: An automotive ignition control system includes a vehicle control computer operable to provide electronic spark timing (EST) signals, a control circuit having a number of coil drive circuits connected thereto, a corresponding number of coil driver devices connected to respective ones of the coil drive circuits and a corresponding number of ignition coils connected to respective ones of the coil driver devices. The control circuit is responsive to an active state of any one of the EST signals to activate a corresponding one of the coil driver devices while inhibiting activation of all others. If any EST signal remains in an active state for an excessive time period, the control circuit is operable to lock-out the corresponding coil driver device from operation until such a fault condition is cleared. The control circuit is preferably operable to accomplish the lock-out function by gradually decreasing the coil current associated with the faulty EST signal in a fashion that does not generate a spark event.

Abstract: A system for providing backup power for a communications system is disclosed. The backup power system of the present invention includes a device for supplying capacitively stored power and a device for monitoring a power level in the communications system. When the monitoring device detects that the power level in the telecommunications system has decreased below a predetermined level, the monitoring device directs the device for supplying capacitively stored power to deliver power to the communications system such that no interruption in power is experienced by the system.

Abstract: A method and apparatus for sequencing the operation of electronic circuits based upon the level of the voltage provided by an external power supply. One or more power supply sequencer circuits may be interposed between an external power supply and one or more electronic circuits. The power supply sequencer circuits comprise a transistor having its high current node coupled to an external power supply, its controlling node coupled to a voltage sequencing means such as a diode and a resistor, wherein the resistor is in turn coupled to the external power supply and the diode is coupled to the ground potential. The transistor has its controlled high current node coupled through a power input node to the power input for the electronic circuit to condition the voltage received thereby. The power input node is in turn coupled through a second resistor to ground potential.

Abstract: A method and system for sequentially addressing multiple components, having a limited number of externally available address lines, on a communication bus. The method and system employs an addressing scheme in combination with a specific interconnection of the components. This combination enables each of the components to be addressed in a sequential fashion by dynamically altering their address. Thus, allowing a virtually unlimited number of components to be coupled to the communication bus without the traditional concerns over the number of externally available address lines.

Abstract: An apparatus for connecting power sources to a plug-in unit has a plug-in connector and a plurality of connection control circuits. Terminal pins of the plug-in connector are connected simultaneously to a negative power source, a GND and a positive power source. When the negative power source and the GND are connected, a first connection control circuit is turned ON and connects the negative power source to a first load circuit. A second connection control circuit is turned on in response to an input from the negative power source supplied to the first load circuit, and supplies a GND signal to a third connection control circuit. The third connection control circuit is turned ON when the GND signal is supplied to the positive power source, and connects the positive power source to a second load circuit.

Abstract: A data protection and recovery system for an energy controller for a water heater is disclosed. The energy controller is a microprocessor based system which includes a central processing unit, volatile and non-volatile memories, and a clock. It functions to energize the water heater only during a certain period of the day. During normal operation of the system, the system uses the volatile memory as a workspace, and normally copies data in the volatile memory to the non-volatile memory. The system senses electrical disturbances, such as power surges, and prevents the writing of any data to the non-volatile memory components during the electrical disturbance. After the electrical disturbance subsides, the system checks the integrity of the data written to the volatile memory, and if it was not corrupted by the electrical disturbance, the data is then written to the non-volatile memory.

Abstract: The present invention is to provide means to attain an improved current efficiency and a stabilized operation even when used to generate high-power magnetic pulses at shortened pulse intervals. The objective is attainable with an apparatus to generate magnetism, comprising a plurality of magnetism-generating circuits which are cascaded each other, each magnetism-generating circuit containing a coil member to generate magnetism and a capacitor to provisionally store the current across said coil member; and a conduction-controlling circuit which is to operate the magnetism-generating circuits in a prescribed order.

Abstract: An AC sequencer receives source AC voltage via a sequencer-mounted universally accepted connector, such as an IEC 309 compatible connector. Source AC is coupled by an AC connector plug and AC power cord from a wall socket to the AC sequencer via a mating connector. Although specifications for the AC power cord and AC connector will vary from country to country, the same AC sequencer may be used in many countries. Further, the AC sequencer receives control and status signals via sequencer-mounted universally accepted connectors, and can respond to signals that may be voltage-sourced, current-sourced, in addition to signals representing switch openings and closures. This permits a master server AC sequencer to be intelligently daisy-chained to remote slave units containing a similar AC sequencer, such that status information may be received from and control signals sent to the slave unit.

Abstract: An electrical load controller circuit for controlling power consumption is described. A detection circuit detects the current flowing through a supply line and produces an output signal representative thereof. A comparator circuit compares the output signal with an adjustable reference signal which is indicative of the maximum power to be consumed by loads connected to the supply line. All of the loads are connected to switching circuits, and these are enabled and disabled by signals received from a decade counter which is in turn controlled by inverters and timer circuits whereby loads can be placed in service in a sequential manner. A modulator intermittently controls the time periods that the electrical load is connected to the supply line as well as the ON and OFF periods of the loads for daytime or nighttime operation.

Abstract: Methods and apparatus for operating a power sequencer/controller system are disclosed. In a typical operation, an AC power sequencer/controller of the present invention senses the current through a first outlet connected to a first load, and when the current through the first outlet exceeds a first threshold voltage, indicating that the first load is turned on, the AC power sequencer/controller provides power to a second outlet so that a second load connected to the second outlet can be turned on.

Abstract: In a power supply control system including first through N-th power supply units for generating first through N-th output voltages, the first through the N-th power supply units producing first through N-th failure signals on occurrence of failure in the first through the N-th power supply units, respectively. A sequence control unit carries out a power on sequence which is for sequentially putting the first through the N-th power supply units into an on state in voltage increasing order of the output voltages and carries out a power off sequence which is for sequentially putting the first through the N-th power supply units into an off state in voltage decreasing order of the output voltages.

Abstract: A ceiling fan and light assembly control circuit including a microprocessor controlled by a single-throw switch and an infrared remote controller operated to regulate the fan speed and the intensity of light. A 60 Hz square wave signal of cycle 16.67 ms is obtained from the alternating current power supply and monitored by the microprocessor. When the square wave signal is interrupted by switching the single-throw switch on and off quickly, the micrprocessor triggers a change in the operation mode of the ceiling fan and light assembly. The infrared remote controller can also be operated to control the fan speed and the light intensity when the single-throw switch is switched on.

Abstract: An electrical current actuated accessory outlet including a power cable receiving mechanism removably securable to a remote electrical power receptacle for receiving a source of alternating current therefrom; and an electric circuit including an electrical receptacle coupled to the power cable receiving mechanism and having an accessory outlet and a tool outlet for delivering the source of alternating current, and a power switching mechanism coupled between the outlets of the receptacle and the power cable receiving mechanism and with the power switching mechanism having an activated mode for automatically allowing alternating current to be drawn from the auxiliary outlet by an auxiliary electrical device when alternating current is being drawn from the tool outlet by an electrical tool secured thereto.

Abstract: Device and method for administering timed orders for the remote control of apparatus, comprising a clock (4) adapted to mark the time, an adjuster (5) for the clock, a programmer (6) permitting selecting an absolute wake up time, a comparator (7) for comparing the clock time and the absolute time, and a control (10) which can have either an active condition in which it sends information for starting the apparatus and to which it is brought by the coincidence of the clock time with the absolute time, or an inactive condition in which it authorizes no operation of the apparatus in the absence of such coincidence. The control (10) is subordinated to a corrector (11 ) for the absolute time which retards or advances a predetermined time relative to the selected absolute time so as to fix a relative time. The control (10) then passes to its active condition at this relative time. The programmer (6) comprises an automatic device (12) for positioning the relative time with respect to the programmed absolute time.

Abstract: An electrical control scheme which permits operating power for a microwave oven and a second electrical appliance, such as a refrigerator, to be withdrawn from a single electrical outlet utilizes electrical contacts across which a voltage differential is generated when the oven is in operation and includes wiring connected between the second electrical appliance and the microwave oven. The included wiring conducts electrical power to the second electrical appliance from the power cord of the microwave oven, and the control system further includes a relay having a normally-closed switch.

Abstract: Activation and deactivation of a plurality of heating elements in an electric heating system are separately controllable in accordance with the present invention. Individual heating elements are sequentially activated in response to a demand for heat. A predetermined time delay is imposed between successive activations of the heating elements to allow time to satisfy the demand for heat before another heating element is activated. Normally, the heating elements are also deactivated sequentially in response to a reduced demand for heat, with a predetermined time delay between successive deactivations to allow time to respond to the reduced demand for heat before another heating element is deactivated. A temperature sensor is located in the air discharge plenum of the heating system for sensing the temperature of the discharge air. The discharge air temperature is used to control the operation of the heating elements, a two-speed heat pump, and the "off cycle" of the heating system blower.

Abstract: A device for controlling the surge of electrical current demanded following the discharge of a lighting system comprised of multiple electronic flash units powered from a common source. Individual electronic flash units are re-charged sequentially by the invention after system discharge, thus limiting the current demand to approximately the level produced by a single strobe light apparatus. The power management device for large electronic flash units can be integrated into the circuits of a strobe light apparatus, a generator, inverter or battery pack itself, or it can be configured as a self-contained accessory device.

Abstract: A method and apparatus is disclosed for transferring electrical power to a balancer 14 without the need for a physical connection between the balancer and the power source 16 or the controller 12 and which also provides for data communication between a balancer 14 and a balancer controller 12.

Abstract: A one time programmable (OTP) electronic switched-output controller apparatus comprises a plurality of switched-output relays which may be power relays, signal voltage relays, dry switching relays or any combination thereof. A power section receives AC line power and provides at least one internal operating DC voltage and provides line AC power to any power relays and to the related power outputs when the relay are actuated. An A-D converter provides DC voltage for internal operation and to any DC voltage relays. A one time programmable microcontroller, which has outputs connected to the relay coils, is programmed before installation in the switched-output controller apparatus to cause actuation of the relay coils in accordance with a preestablished operating protocol. The apparatus is shown connected for receiving RS232 signals and has an internal modem for receiving external signals over a telephone line. A relay enables switching between the RS232 and modem inputs.

Abstract: An intelligent power switching system for controlling the electrical connection of a power source to each of a plurality of outputs, such as personal computer components or electronic entertainment equipment. Switch circuitry is coupled to relay circuitry for generating signals responsive to user commands to select an "on" or "off" state with respect to each output. A processor receives switching signals and generates control signals to effect actuation of the relays. Responsive to user programming commands, the processor stores the switching signals, their sequence and the time delay between their generation. Responsive to a subsequent abbreviated user "power-on" command, the processor generates control signals by reading the stored switching signals, their sequence and time delay, and automatically actuates the relays with respect to each output in the same order and with the same time delay as defined by the user programming commands.

Abstract: A power distribution and control system for computer modules having minimal parts and volume for attachment to a computer cabinet frame which acts as a heatsink. The AC source is split into multiple (M) distribution channels, each of which is monitored by a control unit which operates a solid state relay which permits and/or cuts off line current in that channel. The control units are concatenated so that each current distribution channel operates through 3 through 5 AC cycles before the next succeeding distribution channel is activated. However, each control unit in the system can be individually programmed via external signals.

Abstract: An enhanced method and apparatus for driving an immersed flashing light system used for enhancing algae growth is disclosed. The flashing light system includes a plurality of light source elements that are arranged to illuminate the algae. The light source elements are electrically connected to form ".eta." banks of light source elements. Power is supplied to each bank of light sources in a predetermined sequence at regular intervals to substantially evenly supply each bank of light source elements with a series of power pulses while maintaining a substantially continuous load on the power supply. The power pulses are substantially half cycles of a square wave.

Abstract: The invention is directed to an arrangement for the current-regulated control of several actuators by a control computer. An individual control transistor is provided for each actuator. A single measuring resistor in series with a further control transistor defines a measuring and control arrangement for all actuators. Each individual control transistor for the respective individual actuators is connected in series with respective resistors. The resistance value of each of the resistors corresponds to the resistance value of the measuring resistor. Furthermore, switching elements are provided and controlled by the control computer. The actuators are connected in series with the measuring and control arrangement for a pregiven measuring and control time by the switchover elements. The actuators are normally in series with the individual control transistors assigned thereto.

Abstract: Plural electrical loads supplied with power from a single source are monitored to detect defective loads. Each load is periodically individually energized and current delivered by the source is measured. Measured current for each load is compared with limit values to detect abnormal values. To overcome consequences of supply voltage fluctuations, supply voltage is also measured and admittance of each load is determined from measured current and measured voltage. The admittance value thus determined for each load is compared with limit values to detect abnormal values. Load monitoring of loads energized according to a control algorithm proceeds by periodic momentary suspension of energization according to the control algorithm and energization of selected individual loads.

Abstract: A sequentially shifting control circuit for extendible light strings which includes a main controller in one end, a backward signal-generating circuit in the other end and a plurality of bidirectional shifting control units therebetween. Each bidirectional shifting control unit has a plurality of lights connected thereto, thereby constituting and enabling an extendible light string to be sequentially flashed in a forward direction or a backward direction or in both directions simultaneously. Only three conductive lines are required: one for positive power, one for ground, and one for transmitting different control signals which are represented and distinguished by different voltage ranges, voltage levels, and waveform periods, and are mixed together according to a same signal (synchronous signal) to transmit.

Abstract: A programmable lighting control system for decorative, artistic, and Christmas lighting applications, includes a plurality of outlet receptacles for connection thereto of series or parallel connected Christmas tree lighting strings or the like, a plurality of associated output select switches to individually select a lighting condition signal for each respective outlet receptacle, timing and control circuitry to generate a plurality of lighting condition signals that are applied to solid-state switching devices to drive the outlet receptacles, an output timing phase synchronization feature initiated at user discretion to synchronize the timing phase of each of the plurality of lighting condition signals, and a memory function to retain the last programmed lighting display conditions of user-selected, entirely unique lighting patterns when using a plurality of lighting strings.

Abstract: The disclosed invention achieves a proper speed control of a sheet feeding motor for a serial printer that uses an astable power supply with a simple operation irrespective of variations in power supply voltage. The invention provides a method of and an apparatus for controlling the frequency of a sheet feeding pulse motor for a printer in accordance with the power supply voltage during sheet feeding.

Abstract: A microwave sourced heat exchanger in an inverted, truncated frusta-pyramidal or frusta-conical shaped configuration. A heat conductive medium is carried within microwave transparent pipes toward a microwave source having one or more magnetrons along a split path of increasing parameter. The magnetrons sequentially operate in a cyclic pattern such that the respective magnetrons do not operate when their respective operating temperatures exceed their respective maximum safe operating temperatures. The sequential use of multiple magnetrons increases the efficiency and operating life of the magnetrons. The geometrical design of the microwave heat exchanger allows the heat conductive medium anywhere in the conduit to be directly exposed to microwaves. Further, the geometry of the microwave heat exchanger induces a thermal siphon when the heat conductive medium within is exposed to a microwave source placed at the exchanger's broader base.

Abstract: A heater control apparatus for use with a plurality of printers each having a heater, comprises a detection part for detecting occurrence of zero crossing of a voltage signal supplied from a power supply and for supplying a zero cross signal each time the zero crossing is detected, a signal part for detecting an ON state of a request signal, the request signal being turned ON when a heater of any of the plurality of printers is currently turned ON, a first control part for determining a delay time in accordance with a predetermined device number setting value such that a timing with which a heat-on signal is supplied to a heater of a subject printer lags by the determined delay time behind a timing with which the zero cross signal is supplied by the detection part, and a second control part for supplying a heat-on signal to the heater of the subject heater at a timing defined by the determined delay time only when the request signal is turned OFF, thereby preventing two or more heaters from being turned ON si

Abstract: A method and apparatus is disclosed for transferring electrical power to a balancer 14 without the need for a physical connection between the balancer and the power source 16 or the controller 12 and which also provides for data communication between a balancer 14 and a balancer controller 12.

Abstract: Disclosed is an electrical control circuit (10) for controlling current through a plurality of resistive loads (14(1), 14(2) . . . 14(N)). The control circuit includes a plurality of current control stages (12(1), 12(2), . . . 12(N)), a comparator circuit (18), and a plurality of diodes D.sub.1, D.sub.2. . . D.sub.N-1 in serial connection with the current control stages. The comparator circuit controls the current that is drawn collectively through the loads. The diodes ensure that all preceding current control stages in the series are conducting a predetermined level of current before the next current control stage begins to source current through its respective load. Each current control stage includes an operational amplifier (30), a pass transistor (34), a sense resistor (R.sub.s), and a feedback resistor (R.sub.f). The operational amplifiers are a pre-drive to the pass transistors to allow smaller sense resistors to be used, thereby providing greater efficiency. The feedback resistors (R.sub.

Abstract: A very inexpensive and compact circuit arrangement having low electrical losses and which supplies a load with energy from an AC voltage source by means of a switch-mode power supply unit (22). The load includes at least two partial loads (3, 4) and electric energy is supplied to one of the partial loads (3 or 4) through the switch-mode power supply unit (22) and, as desired, also to at least a second one of the partial loads (4 or 3) directly from the AC voltage source.

Abstract: A programmer for controlling the actuation and deactuation of a plurality of load function switches. A motorized cam drum track moves a follower pivoted about a fulcrum pin. A solenoid controlled by a microcomputer slidably moves a bar operable to selectively latch and unlatch the fulcrum pin. When latched, the pin causes the follower to pivot and effect the actuation and deactuation of the associated switch in response to the cam track and the follower, when the fulcrum is unlatched, leaving the switch unmoved. The solenoid controls latching and unlatching independently of the cam drum rotation.

Abstract: In a power system having a plurality of power units which are supplied with an external power source and output a power source required for a load, multi-way sequential power-on operation is carried out by enabling two power units, designating as masters beforehand, to be turned on immediately when the external power source is turned on. The master, when turned on, transmits a start signal to two other power units, commanding the addressed power unit to be turned on. The addressed power unit, on receipt of a start signal from any of two other power units, turns on and transmits a start signal to two other power units, and thus propagating start signals on two routes beginning with two masters to sequentially turn on power units by twos at a time.

Abstract: A sequential power-up circuit for starting several electrical load elements in series to avoid excessive current surge, comprising a voltage ramp generator and a set of voltage comparators, each comparator having a different reference voltage and interfacing with a switch that is capable of turning on one of the load elements. As the voltage rises, it passes the reference voltages one at a time and causes the switch corresponding to that voltage to turn on its load element. The ramp is turned on and off by a single switch or by a logic-level electrical signal. The ramp rate for turning on the load element is relatively slow and the rate for turning the elements off is relatively fast. Optionally, the duration of each interval of time between the turning on of the load elements is programmable.

Abstract: An electronic control arrangement for controlling the power applied to an electrical load, in which the electronic control includes in its memory a predetermined power control parameter look-up table associated with each of a plurality of potentially applicable voltage ranges. Each table contains the appropriate control parameters for controlling the load when the associated one of the input voltage ranges is applied to the load. The control, in response to an input signal identifying the voltage to be applied, selects the control parameters from the look-up table associated with the identified voltage. This signal may be generated by voltage sensing circuitry which monitors the supply voltage, or by a manually adjustable circuit which enables presetting for a particular supply voltage.

Abstract: A power controlling device capable of controlling the supply power to a drive system and to a control system for controlling the drive system. The power controlling device is provided with a main switch capable of turning on and turning off the power supplying device. When the power supplying device is turned off by the main switch, the drive system is turned off before the control system is turned off.

Abstract: A method and apparatus for controlling application of electrical power from a selected one of a first and a second source of electrical power to a first and a second energy consuming device is disclosed and comprises a first and second switching device connected between the first and second sources of electrical power and the first and second energy consuming devices to control which energy consuming device is energized and in what manner it is energized from either the first or second source of electrical power. A third switching device is connected to the first and second switching devices to control the position of the first and second switching devices. A fourth switching device is connected to the first and third switching devices to control the position of the first switching device through the third switching device.

Abstract: A process and device for controlling heating of a furnace by means of electrical resistors using switching devices, particularly thyristors, associated with the electrical resistors, and whose operation is to be controlled. The switching devices are controlled in syncopated mode by an industrial computer, a programmable industrial robot or equivalent which performs a set of functions which make it possible to compute the power to be dissipated in the resistors, and control directly the switching devices so as to dissipate the previously coputed power. The invention applies particularly to controlling industrial furnaces and more particularly of glassmaking furnaces, particularly furnaces for heating of glass for the tempering and/or bending of the glass.

Abstract: This invention reduces the ripple component of current in the alternating current to, or direct current from, a common power source providing direct current power to a plurality of switched dc/dc power supplies by controlling the time of occurrence of switching of each of the supplies. Each dc/dc power supply is controlled by a switch pulse from a switching circuit which determines the occurrence and duration of time during which each power supply is switched "on". The time of occurence of the switch pulse of each switching circuit is determined by the application of an individual synchronizing pulse to each switching circuit. The combined effect of the ripple components of currents provided to the switched power supplies is minimized by summing these currents with appropriately phased synchronizing pulses applied to the switching circuits.

Abstract: This power adjustment device for electric power systems, in particular for electric power systems with electric ovens, has the aim of optimizing the electric absorption of the system by reorganizing the power requests of the various users comprised in the system. The device comprises elements for detecting the power requests of a plurality of users, a control and management unit adapted to check if the available power is sufficient to feed the requesting users and to enable and disable selectively some of the users operating at that moment according to the available power and according to criteria of priority or of elapsed operating time.

Abstract: An electric tool for driving in fixing elements (10) into an object (4) by means of a magnetic field generated by supplying magnetizing current to an electromagnetic device, comprises a circuit means (17) which is adapted, when activated, to supply magnetizing current to said electromagnetic device. The tool comprises two actuators (18, 19) alternatively connectible to the circuit means (17) and adapted, when actuated, to activate the circuit means, one (18) of the actuators being an actuator which is activatable in a potential-free mode and which is, in an initial position, unconnected to the circuit means, and the other (19) of the actuators being connected to the circuit means in the initial position.