Abstract: Buck converters having a resonant inductor Lr, resonant capacitor Cr, and synchronous switch Q3 that together provide reduced switching loss and soft switching. In operation, the resonant inductor Lr is charged during a time period A. Then, Lr is freewheeling and provides current to an output inductor Lo. Then, Q3 is turned OFF, and energy from the resonant inductor Lr charges the resonant capacitor Cr. Finally, energy from the resonant capacitor Cr is provided to the output inductor and load. The output power can be adjusted by phase control of the operation of switch Q3. In alternative embodiments, the circuit has a pair of coupled inductors L1 L2 or an isolation transformer 40. The coupled inductors have a polarity selected so that the output voltage is reduced, thereby allowing top switch Q1 to have a greater duty cycle. These circuits feature no body diode loss in the switch Q3.

Abstract: A voltage sense circuit and power supply regulation technique. In one aspect, a voltage sense circuit utilized in a power supply regulator includes a transformer including a sense winding and an output winding. A first diode is coupled to the sense winding, a first resistor is coupled to the first diode and a first capacitor coupled to the first resistor and the first diode. A second diode coupled to the first capacitor, the first resistor and the first diode. A second capacitor coupled to the second diode such that a voltage across the second capacitor is representative of a voltage across the output winding. In one embodiment, the first capacitor is discharged in a substantially shorter period of time than the second capacitor such that the second capacitor is charged substantially without influence from leakage inductance energy from the transformer.

Abstract: A circuit arrangement for operating a lamp including a first circuit and a second circuit. The first circuit generates a second DC voltage from a first DC voltage and includes a transformer. The second circuit is coupled to the secondary winding of the transformer and supplies current for the lamp. The secondary winding, input terminals of the first circuit and second circuit are coupled together such that the second circuit is provided with a voltage whose amplitude is equal to the sum of the first DC voltage and the second DC voltage resulting in a more efficient transfer of power by the circuit arrangement to the lamp.

Abstract: The invention concerns a control circuit for controlling a power switch by means of a galvanic insulation transformer, the transformer being produced in the form of planar conductive windings on an insulating substrate (20) whereon are integrated passive components constituting a high frequency excitation oscillating circuit for a primary winding of the transformer, the transformer substrate being directly mounted on a wafer (24) whereon is mounted a circuit chip (40) integrating the power switch.

Abstract: A switching power converter and method of controlling an output voltage thereof using predictive sensing of magnetic flux provides a low-cost switching power converter via primary-side control using a primary-side winding. An integrator generates a voltage representing magnetic flux within a power magnetic element by integrating a voltage on a primary-side winding of the power magnetic element. A detection circuit detects the end of a half-cycle of post-conduction resonance in the power magnetic element after the energy level in the power magnetic element reaches zero. The voltage of the integrator is stored at the end of the post-conduction resonance half-cycle and is used to determine a sampling point prior to or equal to the start of post-conduction resonance in a subsequent switching cycle of the power converter. The primary-side winding voltage is then sampled at the sampling point, providing an indication of the output voltage of the power converter.

Abstract: A self-excited switching power supply circuit is provided which reduces a discharge current generated when an oscillating field effect transistor (3) is turned on, whereby it is possible to reduce energy loss and generation of noise when switching is executed. A time constant of an ON-control circuit (12, 23) is set such that when a polarity of a voltage of a feedback winding (2b) has reversed, a gate voltage of the oscillating field effect transistor (3) exceeds a threshold voltage VTH. Accordingly, after a voltage of a primary winding (2a) has become equal to or less than a power supply voltage, the oscillating field effect transistor (3) is turned on, and electrical charge stored in stray capacitance between the windings of the primary winding (2a) and in parasitic capacitance of the oscillating field effect transistor (3) is discharged gradually.

Abstract: A dc-to-dc converter includes a transformer having a primary winding connected to an input rectifying and smoothing circuit via an FET or like switching device, and a secondary winding connected to an output rectifying and smoothing circuit. A resonance capacitor is connected in parallel with the switching device. A switch control circuit cyclically turns the switching device on and off so as to keep constant the output voltage of the output rectifying and smoothing circuit by feedback control. The switch control circuit drives the switching device in light load mode when a flyback voltage developed by the transformer terminates earlier than each clock pulse, and in heavy load mode, in which each on-off cycle of the switching device is longer than in the light load mode, when the flyback voltage terminates later than each clock pulse.

Abstract: The present invention provides a worldwide compatible switching power supply unit of an RCC system in which by reducing the number of components or parts, reduction of cost can be realized and the mounting space can be reduced. In a high input voltage and in a light load, an inductance of a primary winding of a transistor is set high but in the range of not exceeding a rated value of a main switching element, and in a low input voltage and in a heavy load, an inductance of a primary auxiliary winding and values of a control resistor and a capacitor of the main switching element are set low but in the range of not deteriorating the starting characteristics of the main switching element.

Abstract: A voltage sense circuit and power supply regulation technique. In one aspect, a voltage sense circuit utilized in a power supply regulator includes a transformer including a sense winding and an output winding. A first diode is coupled to the sense winding, a first resistor is coupled to the first diode and a first capacitor coupled to the first resistor and the first diode. A second diode coupled to the first capacitor, the first resistor and the first diode. A second capacitor coupled to the second diode such that a voltage across the second capacitor is representative of a voltage across the output winding. In one embodiment, the first capacitor is discharged in a substantially shorter period of time than the second capacitor such that the second capacitor is charged substantially without influence from leakage inductance energy from the transformer.

Abstract: A DC/DC converter which includes a switched mode power supply, such as a switched mode buck regulator, has gate driven switching devices. A flyback converter is provided for providing a gate drive voltage to the gate driven switching devices. The flyback converter increases or decreases an input voltage to provide the gate drive voltage. A programmable under voltage lockout circuit is provided for turning ON of the flyback converter if the input voltage is lower than a predetermined value. A plurality, n, of buck regulators are connected in parallel and are controlled by a common controller which provides pulse width modulation signals to each power stage which are shifted by 360°/n from each other.

Abstract: A self-excited oscillation type switching power source device is constructed such that when a power source switch is turned on, and the voltage of an input power source increases, the voltage at a point a is increased. When the voltage exceeds a predetermined voltage, a first transistor is turned on, and a second transistor is turned off. Then, a first switching element, when a starting voltage is applied to the control terminal thereof, is turned on, and voltage is developed in a first drive winding. This voltage is fed back to the point a via a feedback circuit. As a result, the transistor is accelerated to reach the on-state. The second transistor is accelerated to reach the off-state. As a result, the first switching element is rapidly turned on, and the oscillation is started.

Abstract: A circuit configuration for generating a switching signal for a current controlled switched mode power supply includes a transformer with windings, a controlled power breaker, in series with a primary winding and a supply DC voltage, a control circuit, for cycle clocked switching of the power switch, a current measuring device measuring the current flowing through the power switch and generating a measured signal as a measure of the measured current value, a reference signal source generating a time-independent constant reference signal, and a comparator circuit comparing the measured signal with the reference signal and signaling the control circuit to switch off the power switch when the measured signal is greater than the reference signal. The reference signal source is connected to a compensation signal source to generate a compensation signal changing over time, the reference signal arising from the sum of the constant reference signal and the compensation signal.

Abstract: A switched-mode power supply has primary and secondary sides, and a transformer (M1) with a primary winding, a secondary winding and an auxiliary winding. The primary winding and the auxiliary winding are connected to the primary side, and the secondary winding is connected to the secondary side. A switch element (T3) is connected to the primary winding in order to interrupt a current flowing in the primary winding. The switched-mode power supply contains a freely oscillating circuit (R5, C3, R7, T1, T2, R8, R9, R10, R11) for generating switching pulses to the switch element (T3). A rectifying and charge storing coupling (D4, C5) is connected between the terminals of the auxiliary winding in order to generate such an image voltage which on the primary side represents a certain voltage of the secondary side.

Abstract: A DC/DC converter which includes a switched mode power supply, such as a switched mode buck regulator, has gate driven switching devices. A flyback converter is provided for providing a gate drive voltage to the gate driven switching devices. The flyback converter increases or decreases an input voltage to provide the gate drive voltage. A programmable under voltage lockout circuit is provided for turning ON of the flyback converter if the input voltage is lower than a predetermined value. A plurality, n, of buck regulators are connected in parallel and are controlled by a common controller which provides pulse width modulation signals to each power stage which are shifted by 360°/n from each other.

Abstract: In an integrated circuit (IC) for providing an enabling signal (EN) to a converter, the integrated circuit (IC) includes a monitoring circuit (FET1, R2, D1, Io, M, S1) for providing a control signal (CS) in response to a level of a line voltage (Vline) on a first connection terminal (8) of the integrated circuit (IC), and a start-up circuit (FET2, Istrt_up, Vcc_strt-Lev, COMP, S2) for providing the enabling signal (EN) to the converter in response to the control signal (CS) and a generated voltage level (Vcc), the generated voltage level (Vcc) being generated in response to the level of the line voltage (Vline) on the first connection terminal (8). The monitoring circuit and the start-up circuit sense the level of the line voltage (Vline) only via the first connection terminal (8).

Abstract: A self-excited oscillation type switching power source device is constructed such that when a power source switch is turned on, and the voltage of an input power source increases, the voltage at a point a is increased. When the voltage exceeds a predetermined voltage, a first transistor is turned on, and a second transistor is turned off. Then, a first switching element, when a starting voltage is applied to the control terminal thereof, is turned on, and voltage is developed in a first drive winding. This voltage is fed back to the point a via a feedback circuit. As a result, the transistor is accelerated to reach the on-state. The second transistor is accelerated to reach the off-state. As a result, the first switching element is rapidly turned on, and the oscillation is started.

Abstract: A switching power supply unit includes a control circuit including a turn-off circuit for turning of a first switch element Q1, which has been in an ON state, and an off-period control circuit for, based on a feedback signal from an output-voltage detecting circuit, controlling the turning-on of the first switch element to be further delayed as a load is lighter. The off-period control circuit includes a transistor as a second switch element which is provided in series between a feedback winding and the control terminal of the first switch element and which is controlled to be turned on and off based on the feedback signal from the output-voltage detecting circuit. A switching frequency is set to be lower as the load is lighter, such that power consumption at the light load is reduced.

Abstract: A self-oscillation type resonant flyback converter includes a series combination of a primary winding and a switching transistor. A secondary winding is connected to a power diode and to an output capacitor. A feedback winding is connected to a delay driving circuit comprising a delay diode, a constant-current diode and a capacitor. The delay driving circuit is provided to delay a positive feedback signal from said feedback winding, so that when said power diode becomes non-conducting, said delay diode becomes in the reverse conduction state, starting a free resonance period that concludes when the said delay diode becomes non-conducting and the switching transistor is achieved at zero voltage switching.

Abstract: In order to reduce a power consumption in a standby state of a load of a switching power source by intermittently controlling an oscillation of a switching element of the switching power source when the load is in the standby state, a time period covering a time at which a voltage of an A.C. power source 10 is a peak is detected by an intermittent oscillation control circuit 12 and supplies the detected time period to a switching control circuit 13 through signal transmission circuits 14 and 15 to allow an oscillation of a switching transistor Q1 for only that period while stop the oscillation thereof for other time than that time period. Since it is possible to perform the oscillation of the switching transistor Q1 for only a charging time of a smoothing capacitor C1 provided on a primary side of a switching transformer of the switching power source, a variation of a voltage on a secondary side of the switching transformer is minimized.

Abstract: A switching power supply apparatus has a transformer having a primary winding and a secondary winding, a first switching element connected in series with the primary winding, a first control circuit for controlling the on-time of the first switching element whereby the output is controlled, and a rectification circuit for rectifying the output from the secondary winding, whereby input voltage is applied to the first winding when the first switching element is on and causes current to flow therein so that energy is stored in the transformer, and the energy stored in the transformer is released as electric current from the secondary winding when the first switching element is off, and the current is rectified in the rectification circuit to obtain an output.

Abstract: A synchronous rectifier is disclosed which makes use of current driving technique to enable low conduction loss in converter rectifiers. In addition to a low loss switch the present invention comprises essentially a transformer with a plurality of windings with at least one current sensing winding, one driver winding which provides driving signal for the synchronous rectifier, and windings for energy recovery. This synchronous rectifier is self-driven but operates independent of converter input voltage hence allow wide input voltage range. It also avoids effect of leakage inductance in converter transformer windings. With energy recovery means it can operate with high efficiency. This synchronous rectifier can operate in many different circuit topologies.

Abstract: A self-oscillation type switching power supply apparatus comprises: a transformer T having a primary winding N1, a secondary winding N2, and a feedback winding N.sub.B ; a switching transistor Q1 for interrupting a current in said primary winding N1; a controlling transistor Q2 for controlling a positive feedback signal for said switching transistor Q1 from said feedback winding N.sub.B ; a time constant circuit adapted to be charged by a voltage produced in said feedback winding N.sub.B at a predetermined time constant and to give a controlling voltage to said controlling transistor Q.sub.

Abstract: The invention is directed to an electronic switched-mode power supply for supplying power to an electrical energy-absorbing device from an AC or DC voltage source of different voltage levels, with a primary switched-mode flyback converter which includes a transformer having its secondary winding connected in series with the electrical energy-absorbing device and a first diode, while its primary winding is connected in series with the collector-emitter circuit of a first transistor having its base connected to the one end of the secondary winding of the transformer through a feedback capacitor, the base of the first transistor being further connected to the one pole of the input voltage source, wherein several feedback capacitors are provided which, during the transformer discharge cycle, are connected to the secondary winding of the transformer, acting as parallel-connected capacitors, and which, during the transformer charge cycle, are connected to a branch comprising the base-emitter circuit of the first tr

Abstract: In a half-bridge self-exciting switching power supply, an over-voltage detector receives the power supply output and generates an over-voltage signal when the power supply output exceeds a preset limit. An over-voltage cut-off circuit is connected to a pulse-width-modulated controller and a driving unit of the switching power supply. The over-voltage cut-off circuit applies a pull-down voltage to the driving unit so as to inhibit self-exciting operation of first and second self-excited switching circuits of a half-bridge self-excited circuit, and disables the pulse-width-modulated controller upon reception of the over-voltage signal from the over-voltage detector. Therefore, when the pulse-width-modulated controller or the driving unit becomes defective, the switching power supply can be cut-off automatically in order to prevent damage to a load and to the other components of the switching power supply.

Abstract: The approach to measuring load current in a multi-phase bridge inverter circuit connected to a multiphase load involves placing a single current sense resistor in series with the inverter circuit and power supply. The current flow through the sense resistor is sampled during a portion of the switching cycle wherein the inverter is configured to enable current flowing through the multi-phase load to flow through the sense resistor. Typically, this will occur during a portion of the switching cycle (e.g. PWM cycle) wherein the load is being actively driven. For a 120.degree., 3-phase, 6-step commutation sequence typically used to control a d.c. brushless servo motor, the sampled current is a time-multiplexed measure of the current flow through each load phase. The same sense resistor is also used for indicating a short circuit condition by comparing the voltage across the resistor to a reference voltage.

Abstract: A direct current to direct current converter utilizes a MOSFET half-bridge configuration in which the inherent magnetizing and leakage inductances of the transformer are used as the only inductances in the frequency-determining circuit. Diodes are used to limit the voltages across the capacitor of the frequency determining circuit and hence limit the short circuit and open circuit characteristics of the converter. A self-starting circuit insures that the circuit will start up when initially energized. Regulation of the circuit is provided by varying the on times of at least one of the two MOSFET transistors in the half-bridge configuration.

Abstract: In a self-oscillating power-supply circuit for charging a battery, a switching transistor (T2) is turned off if the voltage across a sensing resistor (R3) exceeds the threshold voltage of a zener diode (D5). The zener diode is arranged in parallel with the series arrangement of the base-emitter junction of the switching transistor and the sensing resistor, so that the voltage of the battery does not influence the peak current at which the switching transistor is turned off. A diode (D6) is arranged in series with the zener diode and can be short-circuited by means of a switch (T3) in order to switch the power-supply circuit from slow charging to rapid charging. A voltage sensor (R8, R9, T4) monitors the battery voltage and eliminates the short-circuit of the diode (D6) when a given battery voltage is reached so that the power-supply circuit changes over to slow charging.

Abstract: A low-cost and highly reliable flyback isolation-type switching power supply comprises a main transformer and an auxiliary transformer. A secondary winding of the main transformer is connected in parallel with an input winding of the auxiliary transformer. A series network of a diode and a capacitor is connected between the terminals of an output winding of the auxiliary transformer, and a voltage corresponding to the output voltage of the power supply is obtained across the capacitor. The main transformer and the auxiliary transformer preferably share a core having a plurality of bobbin sections, with the windings of each transformer wound around respective different bobbin sections. The equivalent degree of coupling between the secondary winding and the output winding is thus sufficiently larger than the degree of coupling between the primary winding and the output winding.

Abstract: In a self-oscillating power-supply circuit for charging a battery, the main switching transistor is turned off by a second switching transistor (T2) of an opposite conductivity type, which is arranged in series with the main switching transistor (T1) via a sensing resistor (R8). This configuration allows rapid switching of the main switching transistor (T1). The power-supply circuit can be turned on and off in a simple manner (R7, T4). Moreover, it is simple to provide a compensation (R4) for varying mains voltages, an auxiliary voltage (D6, C4) for powering additional circuits (R9, R10), which auxiliary voltage also remains available when the power-supply circuit is turned off.

Abstract: This invention is designed to reduce the number of parts in the circuits of a constant-voltage automatic charging strobe circuit, thus reducing the cost. In addition, it allows a user to decide when to use the strobe flash. In a oscillation charge/discharge circuit, an oscillation startup switch is installed between a battery and a transistor through the primary coil of a step-up transformer. When the switch is closed, the direct current input to the transistor is suppressed, and an abnormal input current control resister may have a low resistance value. A trigger flash circuit comprises a circuit that both controls the constant-voltage flash of a neon lamp NE and controls the oscillation stop of the transistor. A recharge circuit comprises a circuit that uses the resistor in the primary coil of the step-up transformer and a capacitor that takes out pulse fluctuations when the xenon lamp Xe is flashed.

Abstract: A transformer has a primary winding including a first end which is connected to a first input terminal. A switching transistor is connected between a second end of the primary winding and a second input terminal. Timing circuits control an on-off operation of the transistor while a rectifying and smoothing circuit provided on the secondary side of the transformer rectifies and smooths an output from the transformer. In the switching power circuit, a parallel circuit of a capacitor and an inductance element absorbs charges from the capacitor connected in series to the primary winding of the transformer, while a resonance capacitor connected between the collector and the emitter of the switching transistor forms a voltage resonance circuit with the main inductance of the primary winding of the transformer.

Abstract: An inverter power supply having a DC source, a transformer having a primary winding, a secondary winding, and a feedback winding, an L-C resonant circuit of a capacitor and the primary winding, and a self-excited oscillator. The oscillator includes an L-C resonant circuit and an FET connected in series with the primary winding across the DC source to generate a high frequency voltage across the primary winding, a feedback voltage across the feedback winding and a resulting output AC voltage across the secondary winding. A biasing capacitor is connected in parallel with a series combination of the L-C resonant circuit and the FET across the DC source to be charged thereby. The biasing capacitor is also connected in series with the feedback winding to provide an offset voltage which is additive to the feedback winding to give a bias voltage applied to a gate of the FET so as to alternately turn on and off the FET for driving the self-excited oscillator.

Abstract: Overload protection for an AC/DC converter is formed by a high frequency AC power signal provided to a step-down/isolator circuit which converts the power signal to a low voltage signal. An output filter stage then converts the low voltage AC signal to a DC output for use in DC devices. Upon the occurrence of a short circuit or a current overload, the step-down/isolator circuit core becomes saturated, ceasing operation of the step-down/isolator until the short or the connected device drawing the current overload is removed.

Abstract: A high efficiency high power DC to DC power converter and controller system for a CD ignition system with a simple converter controller (8) for controlling a power switch (2) of a transformer (1) operated as a flyback which includes a lossless snubber (6) and simple current sensor (8a) for sensing and controlling the power converter current, and further including ignition trigger conditioner (9) and phase conditioner (10) for operating a trigger output circuit (11) based on an octal counter (67) for triggering ignition coil circuits of a preferred distributorless ignition circuit of the hybrid ignition system type.

Abstract: In a switching power supply circuit in which a primary winding of a, transformer is connected to a DC voltage source through a switching transistor which is turned on and off at a predetermined frequency by voltage of auxiliary windings of the transformer, an integrating circuit is provided between the auxiliary winding of the transformer and the base of the switching transistor for making the waveform of base driving current for the switching transistor similar to the waveform of collector current in a steady state. In parallel with this integrating circuit, a differentiating circuit is provided between the auxiliary winding N3 of the transformer and the base of the switching transistor for operating only at the start of the switching power supply circuit to supply base driving current of a large magnitude to the switching transistor.

Abstract: A blocking-oscillator switched-mode power supply for sinusoidal current consumption includes a transformer having a primary winding. A smoothing capacitor is connected to the primary winding. A bridge rectifier is connected to the smoothing capacitor. A semiconductor switching element is connected to the primary winding for the clocked application of an alternating voltage, being rectified by the bridge rectifier and smoothed by the smoothing capacitor, to the primary winding. A control device is connected to the semiconductor switching element for triggering the semiconductor switching element. A current pump is connected to the smoothing capacitor and to the bridge rectifier for receiving current from the bridge rectifier during a turn-on phase of the semiconductor switching element and outputting a charged current to the smoothing capacitor during a blocking phase of the semiconductor switching element.

Abstract: The present invention is an ON/OFF type self-oscillating DC--DC converter with zero voltage switching and is provided with a transformer, a switching element on the primary side and a diode on the secondary side of the transformer, and configured so that the current (signal) flowing in the secondary side is detected by a resistor. The detected current is delayed by a comparator and provided with a short circuit which shorts the diode driven by the delayed signal. The present invention uses this arrangement to perform a switching operation at zero volts so that there is no switching loss, to improve the conversion efficiency and to have stable transmission operation even for non-load operation.

Abstract: A freely oscillating switched-mode power supply includes a transformer having a power winding for providing an output voltage, a drive winding for providing a switching voltage and a regulating winding for providing a measuring voltage. A switching transistor provides a cutoff voltage to change the output voltage. A rectifier receives the measuring voltage and generates a control voltage representative of the measuring voltage. A first voltage divider receives the control voltage and turns the switching transistor on when the cutoff voltage is above a first threshold value. A second voltage divider receives the control voltage and turns the switching transistor off when the cutoff voltage is below a second threshold value.

Abstract: Disclosed is a switching power source device for supplying a DC stabilized voltage to industrial or household electronic appliances. The power source device can restrict a change in the switching frequency due to the change in load so that low noise and high efficiency can be realized. The power source device includes a first rectifying and smoothing circuit and a second rectifying and smoothing circuit. The first rectifying and smoothing circuit includes a rectifying diode and a smoothing capacitor. The second rectifying and smoothing circuit includes a rectifying diode and a smoothing capacitor.

Abstract: An inverter power supply includes a DC supply providing a DC voltage from an AC mains, a transformer having primary, secondary, and feedback windings, and a self-excited oscillator energized by the DC supply to generate a high frequency voltage across the primary winding and induces across the secondary winding an output AC voltage for driving a load. The oscillator comprises an FET connected in series with the primary winding. A biasing capacitor is connected in series with the feedback winding across a source-gate path of FET for providing an offset voltage which is additive to a feedback voltage at the feedback winding to give a bias applied to a gate of FET so as to alternately turn on and off FET for self-excited oscillation.

Abstract: In a power supply circuit, upon turning on of a switching element, a sinusoidal resonance current flows through a series resonance circuit and a smoothing capacitor of a dc output circuit is thereby charged. This resonance current is reversed after a half cycle and a rectifying diode is thereby reversely biased whereby the resonance path is cut off and the resonance current is automatically ceased. While the switching element is on, exciting of an inductance and charging of a capacitor are made in a parallel resonance circuit, though resonance is not made therein. By turning off the switching element in a current zero state thereafter, a parallel resonance by the parallel resonance circuit is started. The switching element is turned on at a timing when voltage of the parallel resonance circuit has returned to a power source voltage.

Abstract: The present invention is a driving circuit that comprises a magnetically permeable core, a high voltage secondary winding around the core with the secondary winding being connectable to a device to be powered, a circuit connectable to a D.C. power source and being magnetically coupled to the secondary winding to induce a voltage thereacross sufficient to power a device, a plurality cf connected windings wound around the core, a RC network and a plurality of parallel connected transistors coupled to the windings and the RC network with each respective transistor having a base terminal connected to the RC network by a respective current-variable resistive element, and a first primary winding connected in series with a plurality of second primary windings, and each primary winding connected in parallel with a respective capacitor.

Abstract: A high current battery charger of the driven blocking oscillator type includes a three-winding transformer. The primary winding is connected in series with the collector-emitter path of a switching power transistor. The secondary winding is connected in series with the collector-emitter path of a sense transistor which responds to the current flowing through the switching power transistor. The tertiary winding is connected in series with the battery, series-connected batteries or series-connected battery packs sought to be recharged, via a diode, which may be connected in parallel with a capacitor. The battery or batteries are charged by current pulses and discharge through the tertiary winding to repolarize the diode (and capacitor if present). The secondary winding is poled, with respect to the tertiary winding so that the blocking oscillator is driven by energy from the battery or batteries.

Abstract: A power source driving an electrical device includes a DC power supply providing a rectified and smoothed DC voltage from an AC main power, a self-oscillator energized by the DC power supply to generate a high frequency voltage, and a transformer which provides an output voltage from the high frequency voltage for driving a load circuit of the device. The characterizing feature of the power source resides in that the self-oscillator comprises a class C amplifier and includes a bias stabilizing circuit which provides a stabilized bias to the class C amplifier for assuring constant and optimum operation irrespective of possible variations in the supply voltage as well as load variations.

Abstract: A self-oscillation type converter comprises a transformer and a switching transistor. The switching transistor is connected in series to a primary winding of the transformer. A start current is applied from a power supply line to the switching transistor through a start resistor, so that the switching transistor is rendered conductive. A positive feedback is performed through an application of a constant current from a constant current circuit to a base of the switching transistor in response to a voltage generated from a feedback winding, whereby the switching transistor is turned on rapidly. A CR time constant circuit is connected to an output of the constant current circuit. An output of the CR time constant circuit is applied to the base of the transistor, a transistor Q2 is turned on after a lapse of time determined by a time constant of the time constant circuit, so that the switching transistor is forcibly turned off.

Abstract: An electronic large current switch for a single power circuit has a DC-to-DC converter for low voltage transformation, the operation of which is controlled by a control switch or a periodic switching circuit and a switching transistor supplied with the low voltage output of the DC-to-DC converter as its base bias voltage and which controls the power supply to an electrical load circuit so as to be capable of minimzing the power loss of the switching transistor and making the product small and integrated.

Abstract: An on-on type switching regulator comprises a blocking oscillator, rectifying-smoothing circuit, and a voltage drop circuit. The blocking oscillator includes a transformer having a collector winding, base winding and secondary winding, and a transistor. The rectifying-smoothing circuit comprises a rectifier diode, flywheel diode, choke coil, and smoothing capacitor, and is connected to the secondary winding. The voltage drop circuit is connected in a closed circuit which is formed between the base winding and the base-emitter of said transistor, said voltage drop circuit being arranged to block any forward or backward current when the voltage thereacross is in a micro-voltage range which may occur before excitation energy in the choke coil is discharged.

Abstract: A transformer employed in a power supply circuit of a ringing choke converter type comprises two feedback windings which share the current to be supplied to the base of a switching transistor for blocking oscillation. By virtue of the provision of the two feedback windings, a speedup capacitor for delivering a trigger current to the switching transistor is allowed to have less capacity, while the amount of heat generation of a resistor for regulating the trigger current can be restrained. These advantageous features of the present invention produces the effect that the bulk and weight of the capacitor and the resistor can be reduced, which leads to curtailing of the cost of the components as well as enhancing of the reliability of the circuit. The effect is more appreciable when a higher output is required.

Abstract: A series voltage regulator having a regulating transistor (T.sub.1) arranged with its emitter-to-collector path in a series arm of the regulator, the base of which is controlled via a control transistor (T.sub.2) by a first differential amplifier (V) which compares a reference voltage (U.sub.REF) with a voltage proportional to the voltage (U.sub.2) of the regulator output. A differential circuit (V.sub.2) which compares the collector-to-emitter voltage of the regulating transistor (T.sub.1) with an auxiliary voltage (U.sub.3) is provided, the output of which is followed by a current limiting circuit (T.sub.3) which acts upon control transistor (T.sub.2). The auxiliary voltage (U.sub.3) is larger than the collector-to-emitter voltage of the regulating transistor (T.sub.1) which occurs at the beginning of the saturation state of the regulating transistor. The current limiting circuit (T.sub.3) limits the current delivered by the control transistor (T.sub.2) to the base of the regulating transistor (T.sub.

Abstract: A high efficiency, low cost solid state power supply for gas discharge or other devices including a resonant oscillator having a high voltage transistor and a switching circuit connected to the high voltage transistor adapted to rapidly turn-off such transistor. The switching circuit including transistors interposed to interrupt the emitter current path of the high voltage transistor to force rapid cut-off thereof. The switching circuit coupled to the oscillator output tank capacitance which functions additionally as a differentiator to actuate the switching circuit.