Abstract: A DC-DC power converter having a power transformer primary winding and a secondary winding producing a regulated output using a control technique and circuit to control the magnetic flux reset time of the core of the power transformer. The control circuit for the power converter provides control of the on and off time of the power transformer by controlling the magnetic flux reset voltage produced on the secondary winding, thereby controlling the duty cycle of the power transformer, and thereby regulating the output of the power transformer. Because control of the power transformer is accomplished by controlling the secondary winding reset voltage, input-to-output isolation and improved converter stability is provided. Minor variations to the input section of the DC-DC converter allows for a wide range of input voltages. Minor variations to the control circuit configuration provide the capability for short-circuit protection and inrush current limitation.

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: A circuit configuration for a self-oscillating blocking-oscillator switched-mode power supply includes a transformer having a primary winding. A bridge rectifier has an output terminal. A semiconductor switch element is used for clocked application of an alternating voltage rectified by the bridge rectifier and unsmoothed to the primary winding. A control device has input terminals. The control device triggers the semiconductor switch element according to at least one primary current signal to be applied to one of the input terminals of the control device. A one-way rectifier configuration has an input side connected to the output terminal of the bridge rectifier and an output side connected through an RC element to the one input terminal of the control device.

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: A high frequency heating apparatus such as microwave ovens includes an inverter circuit having a switching element and converting a commercial ac power supply to a high frequency power supply by controlling "on" and "off" periods of the switching element, a magnetron driven by the inverter circuit, a counter cumulatively counting an operating period of time and a deenergization period of time of the magnetron, and a compensator for compensating an "on" period of the switching element based on a count value of the counter so that an input power to the inverter circuit is rendered constant.

Abstract: A solar powered battery reclaiming and charging circuit is provided having a high frequency section (a bistable multi-vibrator, relaxation blocking bistable multi-vibrator or an oscillator inverter circuit) which is solar powered and output coupled by a close coupled RF transformer to the battery connected output section. The transformer has a secondary winding producing a current-voltage full wave output sharply defined through a two diode rectifying circuit to a multi-frequency 10 KHz to 100 KHz pulse output. The sharp pulse outputs with RF content in the 2-10 megahertz frequency range have specific frequencies equal to natural resonant frequencies of the specific electrolytes used in respective batteries. These resulting high frequency RF output signals in each pulse envelope structure are capable of reclaiming, maintaining and charging batteries that possess a liquid electrolyte or jell electrolyte and are beneficial to dry cell batteries as well in extending battery life.

Abstract: A DC to DC converter employs a single ended blocking oscillator which employs a transformer having a primary winding and a plurality of secondary windings. The transformer has a core which is of a square loop hysteresis type. The blocking oscillator is supplied operating voltage by means of a voltage regulator circuit which operates to regulate the voltage applied to the blocking oscillator according to both input voltage variations and output load variations. Due to circuit operation, the output voltage is extremely well regulated while having low ripple. An output secondary winding of the transformer is coupled to a rectifier. The rectifier output is fed back to the regulator to control the voltage applied to the blocking oscillator to cause the blocking oscillator to provide a waveform to maintain the output voltage constant.

Abstract: An a-c/d-c microwave oven adapted to be connected to an a-c and/or d-c power source. The oven has an inverter for converting d-c power to a-c power to feed power to a magnetron generating high-frequency energy via a transformer. Input from the d-c and a-c power sources is selectively fed to the magnetron. A first primary winding is fed commercial a-c power. A second primary winding is fed on a-c voltage from the inverter. A secondary winding connecting to the magnetron is wound on the transformer. A predetermined voltage is adjusted in the secondary winding of the transformer by adjusting the frequency of the a-c voltage from the inverter at a higher level than the commercial a-c power, which is fed to the second primary winding.

Abstract: A switching power source device includes a rectifying smoothing circuit made up of a full-wave rectifier 2 and a small-capacity capacitor 3, a resonance frequency controlled type resonance converter circuit 4 having a controlled resonance frequency, a power source regulating transformer 7 having a primary winding N.sub.1, a secondary winding N.sub.2 insulated from the primary winding N.sub.1, and a control winding at right angles to the primary and secondary windings, a controller 9 for controlling the controlling current of the power source regulating transformer 7 and a rectifying smoothing capacitor 8 determining the ripple voltage of the dc output voltage from the power source regulating transformer 7 in conjunction with the load power. With the switching power source device, the harmonic distortion in the ac input current is diminished and the ac input voltage is improved to a sinusoidal wave.

Abstract: A switching regulator, which applies output DC voltage to a load via an oscillator oscillatable between ON and OFF states, has an oscillation controller to control the oscillation of the oscillator based on the load so that a frequency of the oscillating of the oscillator is kept lower than a predetermined frequency irrespective of the load.

Abstract: A switch mode power supply (10) including a switch control circuit (26), a switching device (28), and a plurality of transformers (38) and (40) is disclosed. Turns ratios of the transformers (38) and (40) are selected to produce desired output voltages within acceptable tolerances. A voltage from an output (46) is selected as a feedback voltage and is provided through an isolator (76) to the switch control circuit (26) for regulation thereof. The power supply (10) is characterized in that desired output voltages are produced without the use of supplementary voltage regulators. Output voltages from the transformers (38) are combined and rectified, as required, to produce needed derivative voltages.

Abstract: A self-resonating power supply for controlling operation of an electrostatic air cleaner wherein the ouput voltage to the cell is limited to a desired value by means of a regulated feedback circuit so as to prevent nuisance arcing in the cell and to minimize generation of ozone. The feedback circuit detects changes in the output voltage and responds to such changes by changing the biasing of a switching transistor so as to cause the output voltage to return to the desired value.

Abstract: A self-oscillating power supply circuit comprises a series arrangement of the primary winding (N.sub.1) of a transformer (TR), the main current path of a first semiconductor switch (T.sub.1) and a current measuring resistor (R.sub.1). The first semiconductor switch is driven by a second semiconductor switch (T.sub.2) which in turn is controlled by a comparator (CP). The voltage across the current measuring resistor is applied to the non-inverting input (6) of the comparator and, a reference voltage obtained from a reference voltage source (RS) is applied to the comparator inverting input (5). By arranging a capacitor (C.sub.2) between the output of the second semiconductor switch and the inverting input (5) of the comparator, the first semiconductor switch rapidly turns-off at the end of the forward phase at an accurately determined current through the primary winding.

Abstract: The present invention relates to a switching power supply for a microwave oven in which a DC power is changed to a pulse by means of a switching element coupled to a primary winding of an inverter transformer to supply the power to a high frequency oscillator (hereinafter referred to as the magnetron) coupled to a secondary winding. The inverter transformer has a supplementary winding which is coupled to control side of the switching element to form a self-excited voltate resonance type. As to the self-excited type, a switching frequency is changed by itself relative to the change of the input voltage and output power for stabilizing the output, thereby realizing same level of operation as a power switching circuit compulsory excited from outside control circuit (hereinafter referred to as The Outside-excited type).

Abstract: The transformer of a blocking oscillator converter is magnetized in a flux phase during which a switch on its primary side is switched on. In a blocking phase, in which the switch is switched off, the transformer is demagnetized by giving off energy to a load connected on the secondary side. In order to ensure for the switch to be switched on only after the transformer is fully demagnetized, a transfomer voltage is formed and the switch is only allowed to switch on when the voltage of values with a polarity has returned to finite values with the opposite polarity. The threshold value begins at zero or a value of the first polarity after the switching power supply is put into operation and then shifts to values of a second polarity if the shift does not begin before the time at which the voltage at the load rises.

Abstract: An improved self-regulating, no load protected electronic ballast system (10) is coupled to a power source (12) for actuating at least one gas discharge tube (b 66) with a regulated current and limited voltage to maintain the gas discharge tube (66) input and output power at a predetermined value. The improved ballast system (10) includes a filter circuit (11) coupled through a rectification circuit (16) to the power source (12) to provide a filtered output (28). The output line (28) is coupled to a first toroidal transformer winding (58) of self-regulating circuit (17) for monitoring the regulated current coupled to induction circuit (15). The induction circuit (15) includes a primary winding (42) tapped to provide an autotransformer configuration for establishing the magnitude of the regulated current.

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: A DC voltage transformer with an inductance fed by a primary voltage and an oscillator stage switching the inductance for the generation of a secondary voltage. For reliable operation it is provided that the oscillating current flowing through the inductance is detected and automatically limited by the oscillator stage to a presettable value.

Abstract: An autoconverter has an electronic switch activated by turn-on pulses and a circuit arrangement for the formation of the actual value of the current in a primary input circuit. Inrush currents are suppressed within an optimally-broad range of current by providing an electronic switch in the circuit arrangement which forms the actual value of the current, the electronic switch being inhibited during initial power peaks of the current flowing through a current sensor in the primary input circuit.

Abstract: A circuit arrangement for a free running blocking oscillator type switched power pack includes a control means for pulse width modulated drive of an electrical switch element. The control means receives as controlled information, among other things a zero axis crossing detector signal at one input post and a control voltage and a further input post that is dependent upon the output voltage of the switched power pack. To guarantee reliable operation yet yield low power consumption, particularly during the standby mode, it is proposed that a detector means with whose assistance an internal reference voltage is reduced during standby mode be provided in addition to a capacitive coupling of the two input posts. The result is that the undesirable rise in the output voltage in the standby mode and the further boost by the capacitive coupling of the input posts is effectively avoided.

Abstract: A power supply circuit composed of a series arrangement of the primary winding of a transformer (TR), a first transistor (T.sub.1) and a current measuring resistor (R.sub.2). The first transistor (T.sub.1) is switched by means of a second transistor (T.sub.2). The second transistor is controlled by the combination of a first signal which is proportional to the intensity of the current through the current measuring resistor (R.sub.2) and a second signal which is the voltage, filtered by a low-pass filter, across the secondary winding (n.sub.2) of the transformer.

Abstract: A self-oscillating power-supply circuit includes between two power-supply terminals (1, 2), the series arrangement of the primary winding (n1) of a transformer, a first transistor (T1), a first resistor (R1), and a second series arrangement of the secondary winding (n2) and a first diode (D1), with terminals (2, 4) for the connection of a battery (B) and, via a switch (S1), a motor (M). The secondary winding (n2) is connected to the base of the first transistor (T1) via the series arrangement of a second resistor (R2), a first capacitor (C1) and a third resistor (R3), a first zener diode (D2) being arranged between the third resistor (R3) and the first resistor (R1). The ends of the first resistor (R1) are coupled to the inputs (16, 17) of a switching amplifier (15) for turning off the first transistor (T1) at a specific voltage across the first resistor (R1).

Abstract: A switching power supply comprises first switching circuit for making an input voltage on and off, a transformer having a primary winding connected in series with the first switching circuit, first rectifying and smoothing circuit connected to a secondary winding of the transformer and a second switching circuit for releasing the output of the rectifying and smoothing circuit back to the secondary winding of the transformer during the off-period of the first switching circuit. The switching power supply may further comprise a control circuit for controlling on or off the second switching circuit in response to the output of the first rectifying and smoothing circuit. The power supply may alternatively comprise a second rectifying and smoothing circuit connected to additional secondary winding to control on or off of the first switching circuit. Thus a stabilized switching power supply is provided with lower power loss, higher efficiency and lower noise.

Abstract: A strobe trigger pulse generator includes a power supply, an energy storage capacitor coupled to the power supply and a trigger pulse generator which intermittently energizes a trigger pulse transformer to ionize the gaseous interior of a strobe flash lamp. The trigger pulse generator includes a trigger capacitor coupled to the trigger pulse transformer. A trigger capacitor charging device is coupled between the power supply and the trigger capacitor to selectively direct a charging current to the trigger capacitor. The trigger capacitor discharge circuit is coupled to the trigger capacitor to periodically discharge the capacitor through the trigger pulse transformer to generate a high voltage trigger pulse. A charge path disabling circuit is coupled to the current flow path between the power supply and the trigger capacitor to control the charging current directed to the trigger capacitor.

Abstract: A switching power source apparatus of a ringing choke converter system according to the present invention includes an amplifier for outputting a voltatge to be decreased with an increase in output voltage from a switching power source apparatus, an oscillator for generating a sawtooth wave voltage, a comparator for comparing the sawtooth wave voltage output from the oscillator with the detection output voltage from the amplifier, a first control transistor for controlling the oscillator, and a second control transistor for controlling the switching transistor. When the sawtooth wave voltage is lower than the detection output voltage, the first control transistor is turned on, and the oscillator is subsequently turned on. When the sawtooth wave voltage is higher than the detection output voltage, the second control transistor is turned on, and the switching transistor is subsequently turned on. As a result, the switching frequency is set constant by decreasing the duty ratio in the small load period.

Abstract: A strobe trigger pulse generator includes a power supply, an energy storage capacitorcoupled to the power supply and a trigger pulse generator which intermittently generates trigger pulses to energize a trigger pulse transformer. The pulse generator includes a trigger capacitor having first and second leads, the first of which is coupled to the trigger pulse transformer. A trigger capacitor charge circuit includes an input terminal coupled to the power supply and an output terminal coupled to the second lead of the trigger capacitor to establish a current flow path between the power supply and the trigger capacitor to direct a charge current to the trigger capacitor. A trigger capacitor discharge circuit is coupled to the second lead of the trigger capacitor to periodically direct a discharge current from the trigger capacitor through the trigger pulse transformer to generator a high voltage trigger pulse.

Abstract: A resonant switching converter including a first series resonant circuit including a first inductor and a first capacitor connected in series with a voltage source, a second series resonant circuit including a second inductor and the first capacitor, a switch connected in series with said second inductor and responsive to the current in the first inductor for enabling a discharge path through the load for the charge stored by the first capacitor. A first control circuit responsive to the voltage on the first capacitor may also be provided for operating the switch at a controlled voltage to facilitate line and load regulation. A second control circuit responsive to the output voltage may be included to provide line and load regulation. The switch is only closed after the resonant capacitor has charged to its peak value or beyond.

Abstract: A switching regulator for controlling an output voltage by a pulse width of a switching element such as a transistor and the like at a primary side of the switching regulator. The switching regulator is provided with a feedback element which converts an output voltage at a secondary side into a feedback current, and controls an amount of charge of a capacitor (C3) to control a time for which the transistor (Q1) is kept on at the primary side and an amount of charge of a speed-up capacitor (C2) at the primary side. When a small load is imposed, an excessive increase in the output voltage can be prevented by controlling an amount of charge on the capacitor (3) to control the keeping-on-time and an amount of charge of the speed-up capacitor (C2) at the primary side. This also shortens the time for which the transistor (Q1) at the primary side is kept on.

Abstract: In a switch mode power supply, a first switching transistor is coupled to a primary winding of an isolation transformer. A second switching transistor periodically applies a low impedance across a second winding of the transformer that is coupled to an oscillator for synchronizing the oscillator to the horizontal frequency. A third winding of the transformer is coupled via a switching diode to a capacitor of a control circuit for developing a DC control voltage in the capacitor that varies in accordance with a supply voltage B+. The control voltage is applied via the transformer to a pulse width modulator that is responsive to the oscillator output signal for producing a pulse-width modulated control signal. The control signal is applied to a mains coupled chopper transistor for generating and regulating the supply voltage B+ in accordance with the pulse width modulation of the control signal.

Abstract: A self-oscillating power supply circuit comprises a series arrangement of the primary winding (N.sub.1) of a transformer (TR), the main current path of a first semiconductor switch (T.sub.1) and a current measuring resistor (R.sub.1). The first semiconductor switch is driven by a second semiconductor switch (T.sub.2) which in turn is controlled by a comparator (CP). The voltage across the current measuring resistor is applied to the non-inverting input (6) of the comparator and, a reference voltage obtained from a reference voltage source (RS) is applied to the comparator inverting input (5). By arranging a capacitor (C.sub.2) between the output of the second semiconductor switch and the inverting input (5) of the comparator, the first semiconductor switch rapidly turns-off at the end of the forward phase at an accurately determined current through the primary winding.

Abstract: A switching regulator for use with various kinds of electric and electronic equipment as a DC stabilizing power source. The switching regulator has a switching element implemented as an n-p-n switching transistor, an overcurrent detecting circuit for detecting an overcurrent ascribable to a fault, and a start delaying circuit for, after the switching transistor has been caused into an inactive state, feeding to the transistor a starting current which is delayed by a predetermined period of time. When the fault is removed, the switching transistor resumes its turn-on and turn-off operations immediately so as to restore the switching regulator to normal rapidly.

Abstract: In a switch mode power supply, a first switching transistor is coupled to a primary winding of a transformer for generating pulses of a switching current. A secondary winding of the transformer is coupled via a switching diode to a capacitor of a control circuit for developing a control signal in the capacitor. The control signal is applied to a mains coupled chopper second transistor for generating and regulating supply voltages in accordance with pulse width modulation of the control signal. During standby operation, the first and second transistors operate in a burst mode that is repetitive at a frequency of the AC mains supply voltage such as 50 Hz. In the burst mode operation, during intervals in which pulses of the switching current occur, the pulse width and peak amplitude of the switching current pulses progressively increase in accordance with the waveform of the mains supply voltage to provide a soft start operation in the standby mode of operation within each burst group.

Abstract: In a switch mode power supply, a first switching transistor is coupled to a primary winding of an isolation transformer. A secondary winding of the transformer is coupled via a switching diode to a capacitor of a control circuit for developing a DC control voltage in the capacitor. The DC level of the control voltage varies in accordance with a supply voltage B+. A change in voltage B+ produces a corresponding, greater change in the control voltage. The control voltage is applied to the transformer when the diode is conducting for producing a pulse-width modulated control signal. The control signal is applied to a mains coupled chopper transistor for generating and regulating the supply voltage B+ in accordance with the pulse width modulation of the control signal.

Abstract: A ringing choke converter power supply device comprising a ringing choke converter power supply for stabilizing an output voltage by an indirect feedback system; a variable impedance element provided on a primary or secondary side of the power supply; and a control circuit for transmitting a control signal to the variable impedance element in such a direction that an error signal obtained by comparing the output voltage of the power supply with a predetermined reference voltage becomes zero. The variable impedance element, which is preferably a saturable reactor, is interposed between a voltage detection winding and a feedback diode or between the feedback diode and a capacitor when the element is provided on the primary side; and is interposed between a transformer secondary winding and a rectifier circuit, when the element is provided on the secondary side.

Abstract: A control circuit for a power converter which includes a power transformer having a primary transformer winding for receiving an input voltage signal and a secondary transformer winding for generating an output signal provides control of the on and off time of the power transformer by utilizing a control transformer having a plurality of windings. A switch is provided which is coupled to the control transformer. The switch is conductive to render the power transformer on and when non-conducting renders the powder transformer off. Activacation of the switch is controlled through magnetic coupling between the windings of the control transformer to thereby render the output voltage of the power transformer constant while the switch on time remains constant and the switch off time is variable.

Abstract: A protection circuit for a switching mode power supply circuit which outputs a constant voltage interrupts the ON-OFF switching operation of the switching transistor when an overvoltage state is detected. This protection circuit includes a switching transistor, a diode, a phototransistor, a thyristor, and a capacitor, in conjunction with a photodiode, a zener diode and a thyristor. If either an overvoltage is detected or an overcurrent is detected due to the load circuit being short circuited, the protection circuit simultaneously prevent the power supply input from the power input line from being unnecessarily lost.

Abstract: A method and circuit for limiting the output current of a power supply with a self oscillating flyback converter, controls a primary peak current as a function of input and output voltages of the flyback converter. A quotient is formed from two given input variables and multiplied by a first constant. A second constant is added thereto and then multiplied by a third constant. The two input variables are defined by the input and output voltage of the flyback converter. The output voltage of the flyback converter is divided by the input voltage of the flyback converter in the quotient formation. The output variable is provided as a manipulated variable for controlling the primary peak current. The three constants are dimensioned for simulating a formal dependency existing in the flyback converter between the input and output voltages and the primary peak current of the flyback converter.

Abstract: A self oscillating converter with regenerative switching includes circuitry to enhance the gain of circuity to turn off a MOSFET power switch and enhance the regenerative action culminating in turn off in order to eliminate bursting at low loads. The MOSFET power switching device turn off circuitry includes the addition of a supplementary drive transistor operative for counteracting the effects of the parasitic capacitances of the MOSFET power switching device. This permits the converter to operate with the shorter on times and to provide a low ripple output at very low load.

Abstract: A self-excited inverter circuit primarily includes a main transformer two switching elements e.g. the first and second (FET) switching elements, wherein capacitors at both ends of said first FET are charged during a time T.sub.1 -T.sub.2 when said first FET is turned off, and the voltage V.sub.g1 across said first FET is clamped by a charge voltage V.sub.c1 and then, a voltage V.sub.gs is applied across the gate and the source of said second FET for electrical continuity to cause the voltage to be clamped. The clamped state is maintained from T.sub.1 to T.sub.2, the saturation reactor is saturated at time T.sub.3, and V.sub.gs, which has been negative, starts to change toward O, thereby causing the first FET to change to ON; V.sub.q falls towards VPi at TP3 and further towards zero point. Thus, the voltage V.sub.q2 changes to zero to cause V.sub.gs of the second FET to become zero and the second FET to be shut off. When said voltage V.sub.q2 is clamped to a fixed value, a high -V.sub.

Abstract: When the power source voltage is charged to a capacitor between the source side of a MOSFET and a saturation reactor at the time of starting, the gate voltage of the MOSFET is caused to rise. When this charging voltage or the gate voltage exceeds the threshold voltage, the MOSFET is energized. The energization of this MOSFET induces a voltage in the tertiary self-excited oscillation winding through the primary winding, and a part of the induced voltage is applied to the gate of the MOSFET while some other part is applied to the reactor. This causes the magnetic flux of the saturation reactor to be set to the direction opposite that which had been set before. When the product of the voltages applied to the saturation reactor has reached the level for the allowable saturation magnetic flux density the saturation reactor is saturated and the gate voltage is discharged to turn off the MOSFET.

Abstract: In a flyback converter, a 15 Amp N-channel power MOSFET is driven to saturation by a gate voltage derived by connecting the gate to the relatively high-magnitude (150 volt) B+ voltage by way of a resistor of relatively high resistance (about 20 kilo-Ohm). Current flowing through this resistor causes the gate capacitance (3600 pico-Farad) to charge at a rate of about 2 Volt per micro-second. Since the forward transconductance of the MOSFET is 6 mhos or more, a situation has been established where the MOSFET is effectively fully switched ON as long as the MOSFET's drain current does not rise at a rate higher than about 12 Amp per micro-second.Eventually, the magnitude of the gate voltage reaches a predetermined maximum level (about 20 Volt), at which point a threshold device, which is connected between gate and source, breaks down and rapidly discharges the base capacitance, thereby rapidly switching the MOSFET into a non-conducting state.

Abstract: A ringing choke converter which comprises an output transformer having a primary winding, a secondary winding, and a feedback winding and/or a control winding, a main switching transistor having its collector connected to the primary winding and its base and emitter connected to the feedback winding, and a rectifying diode connected to the secondary winding. In accordance with the present invention, a control transistor is connected between the base and emitter of the main transistor; a time constant circuit composed of a resistor and a capacitor is connected across the feedback winding or control winding; the connection point between the resistor and the capacitor is connected to the base of the control transistor; and an adjusting circuit for adjusting the charging time constant of the capacitor in accordance with the output voltage is connected to the connection point.

Abstract: High-tension generator circuit for a particle detector, having a transformer (8, 9) and a voltage step-up circuit (10). The primary 8 of the transformer is fed by means of a power transistor 7 whose drive transistor 6 is controlled by means of a resistance-capacitance circuit (4, 5). In each conduction period of the primary the secondary brings about a reversal of the polarity of the capacitance.

Abstract: A method and apparatus are disclosed for controlling an off-line dc power supply circuit including a printed circuit board. The power supply circuit comprises a source of unregulated dc input power and a power transformer which separates the circuit into a primary side and a secondary side. An error amplifier compares an output dc voltage generated at a secondary winding of the power transformer to a reference voltage to generate an error signal representative of the difference error therebetween. The error signal is coupled from the secondary side of the power supply circuit to the primary side of the power supply circuit by means of a capacitor formed from traces on opposite sides of the printed circuit board. A solid state switch selectively connects the unregulated dc input power to a primary winding of the power transformer to regulate the power supply circuit in the primary side of the circuit in response to the error signal which is generated in the secondary side of the circuit.

Abstract: A converter circuit with an oscillation transistor is provided with a circuit for changing starting resistance for the oscillation transistor to develop a fixed A.C. output voltage on the secondary side of the transformer from input voltages on the primary side thereof.

Abstract: A switching regulator type power supply circuit comprises a converter transformer, a blocking oscillation circuit comprising a transistor having a collector connected to a rectifying output of an AC power supply through the input winding of the transformer and an emitter and a base connected to a positive feedback winding of the transformer, and a switching control circuit connected between the base of the transistor and a fluctuation detecting winding and the positive feedback winding of the converter transformer. Still another switching transistor is connected between the base of the switching transistor and the positive feedback winding and a proportional current supply circuit comprising a coil and a Zener diode is connected to the emitter and the base, the base having a resistor for bias connected thereto.

Abstract: The converter delivers current to an intermittently energized load and includes a coupled inductor having a primary winding, a secondary winding and a feedback winding. A switching transistor is coupled in series with the primary winding of the inductor and switches between conductive and non-conductive states to control the flow of current through the primary winding. A positive drive circuit provides positive bias voltage to the switching transistor. A current limiting circuit senses the voltage across the base-emitter junction of the switching transistor to measure the primary winding current, removes the positive bias voltage when the primary winding current reaches a predetermined value, and thereby switches the transistor out of the conductive state into the non-conductive state.

Abstract: The DC to DC converter includes a coupled inductor having a primary winding and a feedback winding. A drive current regulator circuit receives a variable input voltage from the feedback winding but transmits a constant base drive current to the base terminal of the converter switching transistor. The base drive regulator circuit thereby enables the DC to DC converter to operate at high levels of efficiency over wide ranges of DC input voltages such as twelve to forty-eight volts DC.

Abstract: A switched-mode power supply circuit with having an operating state and a stand-by state in which the value of a first output voltage is considerably lower than in the operating state, whereas the value of a second output voltage is substantially the same. With the aid of a duration-determining circuit (Tr7, Tr8, R17, C12) which is controlled by a switch (Tr6) operative during the stand-by state, a low-frequency burst mode is maintained during this state in which the switch of the supply circuit conducts a number of consecutive times and subsequently becomes non-conductive during a given period. As a result the dissipation in the circuit is reduced.