Abstract: A switched-mode power supply circuit for converting a d.c. input voltage into a d.c. output voltage. The circuit includes a controllable power switch (Tr1) connected in series with the primary winding (L1) of a transformer (T). This winding forms part of a resonant circuit. To reduce the power losses caused by turning on the switch, the drive path of the switch incorporates a delay network (R11, C9) for each time delaying the turn-on until an instant which is substantially half a cycle of the resonance frequency later than the initial instant of the decrease of the voltage across the switch during its previous cut-off time.

Abstract: A switch-mode power supply has a rectifier for producing a small d.c. voltage from an input a.c. voltage, and a converter which comprises a switching transistor and a transformer. The converter arrangement is a free-running conductive converter and the switching transistor is switched on in the currentless state.

Abstract: Apparatus for transferring electrical power between a power supplying apparatus and power consuming apparatus and having a separable high frequency transformer with a primary permanently mounted to the power supply apparatus and a secondary mounted about the power consuming apparatus. A charging control circuit mounted on the consuming apparatus, e.g. a mobile vehicle includes means for detecting current and voltage delivered through the transformer, and also for monitoring storage batteries within the vehicle. The power supply apparatus includes a power supply circuit comprising a ferrite core transformer and capacitor forming a parallel resonant circuit. The primaries of the transformer are alternately driven by a driver about opposing polarities. The drivers are controlled by a voltage-controlled pulse-width modulator which provides a square wave input to the drivers to cause them to alternatively energize the ferrite core transformer.

Abstract: A circuit for energizing a load (10) with different input voltages comprises a transformer (6), having a primary winding (n.sub.1) in series with a switching transistor (T.sub.1) the load (10), and a current sensing resistor (R.sub.2) between the input terminals. The secondary winding (n.sub.2), in series with a diode (D.sub.1) connected is in parallel with the load. A starting resistor (R.sub.1) starts the circuit oscillating via a positive-feedback loop comprising, in series, a first resistor (R.sub.4), a capacitor (C.sub.1) and a second resistor (R.sub.5). This feedback loop is coupled between one end of the secondary winding and the base of the switching transistor. A control transistor (T.sub.2), whose base is connected to the current-sensing resistor (R.sub.2), turns off the switching transistor as a function of the primary current. The energy stored in the transformer is then delivered to the load by an output current in the secondary winding.

Abstract: A power supply with automatic arcing control and overload protection includes an electronic switch in an oscillator circuit with a primary winding of a step-up transformer. A high voltage, secondary winding of the transformer is loosely magnetically coupled to the primary winding. The frequency of oscillation of the oscillator circuit decreases as a load impedance across the secondary winding of the transformer decreases. In the case of arcing or shorting of an output circuit of the power supply the frequency of oscillation decreases below a pass band of the output circuit, thereby reducing the output current of the power supply.

Abstract: A switching power supply has a saturable transformer provided with first to fourth windings. The first winding is inserted in series in a first path from a DC power source to a primary winding of a power transmitting transformer. A main switch is inserted in series in the first path and controlled by an output of the second winding. The operation of the main switch is positively fed back through the saturable transformer. A capacitor is connected in parallel to a series circuit consisting of the main switch and the first winding. An auxiliary source for generating a predetermined direct current output is provided to drive the third winding by a polarity opposite to that of the first winding. An auxiliary switch is inserted in series in a second path from the auxiliary source to the third winding and controlled by an output of the fourth winding. The operation of the auxiliary switch is positively fed back through the saturable transformer.

Abstract: A power source for a developing bias comprises an input power source, a standard voltage generating means which generates standard voltage employing the input power source, a pulse transformer on which the standard voltages are impressed as a direct current voltage to be switched on and off, clock pulse generating means which generates clock pulses with a fixed cycle and fixed duty ratio, and switching means driven by the clock pulses for switching the pulse transformer to provide a regulated output voltage. The circuit of the invention eliminates the need for a feedback loop to compensate for load variations.

Abstract: A self-oscillating circuit particularly adapted for driving the deflection yoke of a cathode ray tube (CRT) or a high voltage pulse transformer is disclosed. The circuit includes an NPN transistor, to the collector of which is coupled a direct voltage source and a first inductance and to the base of which is coupled a second, grounded inductance. Following transistor turn-on, the collector current ramps up in storing energy in the first inductance. With the transistor base drive removed, a voltage spike appears on the transistor's collector to which is coupled a grounded capacitor. The LC network comprised of the first inductance and the grounded capacitance attempts to resonate, with the collector voltage clamped by the transistor collector-base junction.

Abstract: A DC to DC flyback converter for charging a capacitor in which the maximum current supplied from a battery to the converter's transformer is determined solely by the battery recovery voltage, circuit resistances, the transformer turns ratio and semiconductor junction voltages.

Abstract: This invention concerns a power supply arrangement which comprises a direct current power source circuit (A) including a battery (10), a voltage converter circuit (B) including an oscillator circuit (OC), an oscillating transformer (11) and an oscillation starting circuit (OS), a rectifier circuit (C) for rectifying said alternating current voltage to a direct current, and an oscillation stopping means (F) for stopping the current supplied from said battery to a load circuit member (D). The oscillator circuit (OC) includes an oscillating switching element (12) which has a high leak resistance, and the oscillation starting circuit includes a switch element (15) for starting the actuation of said voltage converter.

Abstract: Static inverter comprises a transformer and transistor for intermittent asymmetric energization of the transformer. The transformer includes three feedback windings which in response to saturation of a branch of the transformer core but before full core saturation discontinue regenerative feedback and then apply degenerative feedback. A fourth feedback winding in the transformer assures commutation and re-triggering of the transistor.

Abstract: An electronic device comprises an arrangement which makes it possible to power a transmitter in self-contained fashion from a pick-up without any other power source. The device comprises at least one transistor and a transformer having a high turns ratio. The primary windings are connected in series with controlled electrodes of the transistor. The secondary windings of the transformer act on the controlling electrode of the transistor and the very low voltage is applied across the primary windings and the controlled electrodes. Voltages of a few mV which are thus applied result in the appearance of voltage pulses of a usable magnitude at the terminals of the secondary winding which may be accumulated in a capacitor to feed the transmitter intermittently. This device can be used in a self-contained detector-transmitter for use as a remote fire alarm.

Abstract: In a DC-DC converter for an electronic flash unit disclosed, an npn transistor is used as an oscillating transistor. The emitter of the npn transistor is connected to a main capacitor of the flash unit at least through a secondary winding of the converter. A diode is connected between the secondary winding and the main capacitor in such a manner that the emitter current of the npn transistor can flow into the main capacitor as an charging current through the secondary winding.

Abstract: A DC-DC converter is described of the blocking oscillator type, for charging a battery from a solar cell. The use of a field effect transistor enables the oscillation to be started by the voltage from a single solar cell, even if the battery is fully exhausted. The overall efficiency of the circuit is improved by the use of the base-emitter junction of the switching transistor of the converter as rectifying element for the battery charging current.

Abstract: The converter device transforms a changing direct signal generated by a source of direct current, into a signal whose amplitude is substantially greater than that of said changing signal, at least for certain values of this signal. It comprises a first transistor, an inductance with a high overvoltage coefficient wound on a core of ferrite and arranged in the collector circuit of said first transistor, so that one terminal of this inductance is directly connected to the collector of said transistor, a second transistor of which the collector is directly connected to the base of the first transistor, a connecting capacitor between the collector of the first transistor and the base of the second transistor, and a polarizing resistance arranged between the base of the second transistor and one terminal of said source.

Abstract: A high frequency battery charger operable from a 120 volt AC line power source which is rectified and converted by a blocking oscillator into 20-200 Khz rectified output for battery charging. A sensor for determining full battery charge serves as a power cut off to the battery with provision, if desired, for continued trickle charge of the battery.

Abstract: A simple single-ended inverter circuit efficiently converts a DC input voltage to an AC output voltage. The circuit, which functions as a self-contained Class C oscillator, comprises an energy-storing inductor and an energy-storing tank capacitor in circuit with a saturable core feedback transformer operable to provide intermittent feedback current to effect periodic conduction of a single power transistor. When this transistor is non-conductive, resonant interchange of energy occurs between the inductor and tank capacitor; periodic energy transfer from the inductor both charges the capacitor and also supplies a load, and energy transfer from the capacitor to the inductor provides reset current to the saturable transformer.

Abstract: A power supply circuit for strobo unit includes a DC-DC converter which steps up a low voltage from a d.c. source to a higher voltage. The converter comprises an oscillation transformer, a PNP transistor and an NPN transistor, both of which are used to form an oscillation circuit. The circuit arrangement provides a stabilized oscillation and eliminates the likelihood of producing an electric shock.

Abstract: A static inverter employing an inductor and an electrical gain element for intermittent assymetric energization of the inductor from a dc source is described. Reliable intermittent operation of the gain element, typically a power transistor, is achieved by use of three feedback windings which in response to saturation of a branch of the core of the inductor but before full core saturation, discontinue regenerative feedback and then apply degenerative feedback. This turn off mechanism protects the transistor from high current stresses. Passive means are provided such as a capacitor for momentarily storing the energy or diode means for coupling the energy back to the source or to the load to protect the transistor from the high voltage surge and the energy release when current flow in the inductor is interrupted. Energy stored in the capacitor may be used for transistor commutation.

Abstract: A blocking oscillator DC to DC converter includes a first transformer which is charged up and provides feedback to a switching transistor on one half of the cycle and discharges stored energy from the secondary during the second half of the cycle. To reduce switching losses the first transformer driven switching transistor is turned off by a control transistor disposed between the switching transistor base and ground, the control transistor being turned on and off according to the charge on a base capacitor charged by the first transformer. A second transformer may be included to control the power across a gap disposed to kill flying insects.

Abstract: A DC voltage converter includes an oscillator that converts a DC battery voltage to an oscillating voltage, a low voltage transformer that increases the oscillating voltage to a higher oscillating voltage, and a voltage rectifying-capacitor charging network or multiplier that increases the higher oscillating voltage to yet a higher DC voltage at an output terminal for DC high voltage utilization devices and the like. An electric control switch is selectively actuated by the user to apply the battery voltage to the oscillator, resulting in the generation of the stepped-up DC voltage at an output terminal. Another DC voltage converter has an electronic switching circuit that automatically turns the oscillator on and off and a load capacitor across the electrodes that is charged and discharged to provide a shocking voltage. Utilization devices for the voltage developed by the converter shown are a miniature animal training device and a cattle prod device.

Abstract: A power pack for a d.c. energized device, the power pack providing a predetermined d.c. voltage and being of given shape and dimensions, its output terminals having predetermined positions. This power pack includes a casing having the given external shape and dimensions and two output terminals in said predetermined positions. Inside the casing a d.c. power supply is provided adapted to deliver an on-load d.c. voltage lower than the said predetermined d.c. voltage, and a low consumption converter circuit for converting a signal from the d.c. power supply into a d.c. voltage signal of the predetermined value. The signal from the converter circuit is applied across the output terminals.

Abstract: A multiple output switching regulator power supply operates as a self-oscillating circuit with a light weight ferrite core transformer and a sense winding used exclusively for voltage regulation purposes. A power transistor switch is employed to selectively connect the transformer primary across a DC source of power to provide energy storage when the switch is closed and to provide energy transfer when the switch is open, by way of transformer flyback. The power transistor switch is controlled by a feedback circuit which includes a current sink connected to selectively divert current away from the base of the power transistor switch and a timing circuit for controlling the operation of the current sink. A capacitor, connected across the sense winding is monitored by a high gain voltage comparison circuit which activates the timing circuit in dependence on the voltage variation on the capacitor.

Abstract: A DC voltage converter includes an oscillator that converts a DC battery voltage to an oscillating voltage, a low voltage transformer that increases the oscillating voltage to a higher oscillating voltage, and a voltage rectifying-capacitor charging network that increases the higher oscillating voltage to yet a higher DC voltage at an output terminal for DC high voltage utilization devices and the like. An electric switch portion is selectively actuated by the user to apply the battery voltage to the oscillator, resulting in the generation of the stepped-up DC voltage at the output terminal. Utilization devices for the voltage developed by the converter shown are a miniature animal training device and a cattle prod device. The miniature animal training device has a pair of outwardly projecting electrodes mounted on a side at one end of the housing that is sized and shaped to fit within and conform to the palm of a hand.

Abstract: The invention relates to a power supply circuit utilizing a DC input tied to the primary windings of two transformers. A pulse source drives either primary through a selector switch which selects the desired primary to produce a pulsed transformer output of desired polarity. The transformer secondary windings produce a voltage output discharged by a load supplying capacitor. The voltage output is maintained at a desired polarity and at a peak level by periodically pulsing the load supplying capacitor with the same amount of energy taken by the load.

Abstract: A simple single-ended inverter circuit efficiently converts a DC input voltage to an AC output voltage. The circuit, which functions as a self-contained Class C oscillator, comprises an energy-storing inductor and an energy-storing tank capacitor in circuit with a saturable core feedback transformer operable to provide intermittent feedback current to effect periodic conduction of a single power transistor. When this transistor is non-conductive, resonant interchange of energy occurs between the inductor and tank capacitor; periodic energy transfer from the inductor both charges the capacitor and also supplies a load, and energy transfer from the capacitor to the inductor provides reset current to the saturable transformer.