Abstract: The invention is directed to a switching power supply with a primary switched-mode direct-current converter, in which the conductivity of a transistor (2) driving the base of a switching transistor (1) is operated on by the sum of two control signals. The sum of these control signals is generated by two low-resistance voltage sources in series arrangement, the sources being proportional to the emitter current and the input voltage, respectively.

Abstract: A DC-DC converter for supplying DC power to a load comprises a transformer, a switch, a current detector, a bias voltage adjusting circuit, and a control element for the OFF control of the switch. The transformer has primary and secondary windings for supplying power to the load and also a tertiary winding for driving the switch. The control element is controlled by sum of the variable bias voltage obtained from the bias voltage adjusting circuit and the current detection voltage obtained from the current detector. The switch is converted from the ON state into the OFF state when the control element is turned on.

Abstract: A DC-DC converter for supplying stabilized DC power to a load comprises a transformer, a switch, a starting circuit, a resistor, a capacitor, a control circuit, and a rectifying and smoothing circuit. The transformer has a primary winding, a secondary winding and a tertiary winding. The primary winding of the transformer is connected in series to the switch. The secondary winding of the transformer is connected to the rectifying and smoothing circuit, and the tertiary winding is connected to a control terminal of the switch so as to drive the switch by positive feedback voltage. The capacitor is charged and discharged in response to the ON/OFF operation of the switch. The control circuit converts the switch from the ON state into the OFF state in response to the voltage of the control circuit. The power loss of the DC-DC converter is little.

Abstract: A DC-DC converter for supplying stabilized DC power to a load comprises a transformer, a switch, first and second capacitors, a control circuit, and a rectifying and smoothing circuit. The transformer has a primary winding, a secondary winding and a tertiary winding. The primary winding of the transformer is connected in series to the switch. The secondary winding of the transformer is connected to the rectifying and smoothing circuit, and the tertiary winding is connected to a control terminal of the switch so as to drive the switch by positive feedback voltage. The first and second capacitors repeat charge and discharge periodically. When voltage of the first capacitor attains to the threshold voltage of the switch, the switch is converted from the OFF state into the ON state. When voltage of the second capacitor attains to the prescribed value, the control circuit converts the switch from the ON state into the OFF state. Circuit parts of the DC-DC converter is small in number.

Abstract: A power converter, particularly adapted for supplying high voltage power for a CRT, for converting an unregulated level of input power to a regulated level of output power is described. The power converter includes a self-excited sinusoidal power oscillator comprising a transformer which has a secondary winding that resonates at a resonating frequency in response to the input signal and a field effect transistor connected to operate as a Class C amplifier. The field effect transistor is connected so that both the drain and gate voltages can both be provided by the primary windings of the tranformer and oscillate at the resonant frequencies so that the positive peak gate voltage can be used to control the output of the power oscillator, which in turn controls the power output of the converter. The gate of the FET is connected to a control bus which in turn can be connected to controls for controlling the control signal in accordance with any one of a plurality of control conditions.

Abstract: A variable frequency DC to DC converter generates a pulsed, variable magnitude output voltage where the frequency of the pulsed output voltage varies with changes in the magnitude of the output voltage. An energy storage capacitor is coupled between the converter coupled inductor and strobe flash lamp or other gaseous discharge tube and is periodically discharged through the flash lamp. A variable impedance device in the form of a capacitor is coupled in series with the flow of current from the coupled inductor into the energy storage capacitor to provide a low impedance current flow path when energy is transferred from the coupled inductor into the capacitor and to provide a high impedance current flow path between the converter DC voltage input terminals and the energy storage capacitor when energy is transferred from the capacitor into the strobe flash lamp.

Abstract: Extremely high efficiency is achieved in a DC to DC converter by using a relaxation oscillator in which two transistors alternately conduct current to the primary winding of a step-up transformer. The transistors are interconnected by a resistor and capacitor in series so that when the converter is lightly loaded, the saturable reactor in the circuit will be self-resonant, so as to draw only minimal power from the battery source. The converter also includes a battery charge level monitor circuit that prevents the DC to DC converter from oscillating and thus providing power unless the battery is above a minimum charge level when its voltage is applied to the converter. In a preferred embodiment, the converter provides an output of up to 100 watts.

Abstract: A ringing choke-type DC/DC converter comprising a transformer having a primary winding, a secondary winding, and a feedback winding, an input DC power source connected through a transistor to the primary winding of the transformer, a DC power output connected through a diode to the secondary winding of the transformer, a base circuit having a first capacitor and connected between the base of the transistor and the feedback winding of the transformer, a branch circuit branching from the base circuit and having a Zener diode connected in series with a second capacitor, and an impedance provided in series between the transistor and the branch circuit for preventing the transistor from intermittently operating, thereby stabilizing the DC power output.

Abstract: A transistor oscillator produces at the secondary winding of a transformer output pulses with a pulse width which is dependent upon stored charge in the base of the transistor, the collector-emitter path being connected in series with a primary winding of the transformer and a feedback winding being connected via a capacitive feedback path to the base. The output pulses are rectified and smoothed to produce an output voltage. Regulation of the output voltage is achieved either by a zener diode connected at the output or by reducing the stored charge in the base with a control transistor, which may be a photo-transistor for electrical isolation of the output, whose collector-emitter path is connected in parallel with the base-emitter path of the oscillator transistor.

Abstract: A power supply having a dual-polarity, automatically switchable high voltage output. The power supply includes apparatus for regulating low voltage including a comparator having a programming voltage input and a feedback voltage input. The low voltage is converted by low voltage dc conversion apparatus to both negative and positive polarity high voltage dc signals proportional to the electronic signal applied to the programming input. Apparatus for switching the high voltage output by remote control is provided such that in a first switching mode the high voltage output is derived from the output of the positive polarity conversion apparatus, and in a second switching mode the high voltage output is derived from the output of the negative polarity conversion apparatus.

Abstract: An improved switching power source in which the output of the DC input power source is switched off and on under control of switching elements of an oscillating drive circuit which is supplied to the primary side of a power source transformer and from which a constant voltage output is supplied from the secondary of the transformer. A saturable reactor transformer supplies an input to the control terminals of the switching elements of the oscillating drive circuit and the inductance of the saturable reactor transformer is controlled with the output voltage from the secondary of the power source transformer so as to control the oscillating frequency of the oscillating drive circuit and, thus, stabilize the output voltage at the secondary of the power source transformer so as to obtain an increased conversion efficiency, reduce the size and weight of the transformer, reduce the leakage flux, improve the control range and reduce the cost of production.

Abstract: A regulated high-voltage power supply comprising a tuned-collector type oscillation circuit (3) having an oscillation transistor (TR4), a control circuit (2) for controlling the base current of the oscillation transistor (TR4), a resistance circuit (4) for supplying the base current to the oscillation transistor (TR4) in response to the output from the control circuit (2) and a protection circuit (5) having a protective transistor (TR3) for partially receiving the output from the resistance circuit (4) to attenuate the output from the control circuit (2) when short-circuiting is caused in the area of a load (RL). The protective transistor (TR3) is made conductive upon short-circuiting in the area of the load (RL). In order to delay the oscillation starting time of the oscillation circuit (3) immediately after releasing of the short-circuiting, provided is a time-constant circuit (51) formed by a delay capacitor (C51) and discharge resistors (R51, R52) for discharging the storage charge of the delay capacitor.

Abstract: A DC-DC converter of a laminated, hybrid integrated type comprising a laminated transformer having printed conductor layers on its surface and electronic components attached to the surface. The laminated transformer is formed by alternately laminating a plurality of insulator layers and two sets of conductor layers insulated from each other. The conductor layers are connected at ends to constitute primary and secondary wirings in an inter-layer formation. The laminated transformer has a glass undercoat formed thereon or a laminated capacitor deposited on its surface to provide a base for the other electronic components.

Abstract: An electronic ballast circuit for fluorescent or other gaseous discharge lamps includes a resonant half-bridge inverter circuit. The source voltage to the inverter is a full-wave rectified line voltage together with a DC carry-over voltage for supplying power in the inter-cusp period of the recitified line voltage. A negative feedback circuit is responsive to lamp current to vary the inverter drive frequency and thereby regulate lamp current. The frequency response of the feedback loop is high enough and the gain-versus-frequency response of the inverter is such that lamp current and voltage are regulated to reduce the crest factor of lamp current to compensate for variation in the amplitude of the voltage across the semi-conductor switches.

Abstract: In a self-oscillating type switching power supply in which an input source, a primary winding of a transformer, and a switching element are connected in series, and a constant output is supplied to a load from a secondary winding of the transformer by the operation of the switching element, in order to obtain a signal to turn off the switching element, a sense circuit for detecting the output of the switching power supply is provided, and the analog signal from the sense circuit is inputted to one winding of a saturable reactor, and at a time point when the switching element is to be turned off, the analog input signal is converted into a pulse signal insulated from the analog input signal, and the pulse signal is outputted from another winding of the saturable reactor. By such a system, a switching power supply having a very simple circuit arrangement and high output voltage precision can be achieved.

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: In a signal transmission system whose transmission line (16) is connected to a line side component (66, 68) of a respective transmitter (12) and receiver (14) and is electrically isolated from the operating side, the line side component (66, 68) of the respective transmitter (12) and receiver (14) is powered from the operating side over through an isolating DC/DC-transducer (10).

Abstract: A switched-mode power supply circuit 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.

Abstract: A self-oscillating power supply circuit for charging a battery in which energy is stored in a transformer (Tr) during the so-called forward intervals. This energy is applied as a charge current to the battery (6) during the flyback intervals. To prevent overcharge of the battery, the circuit includes a battery voltage protection circuit (10) receiving its power supply from the battery. A fraction of the battery voltage is applied to this circuit by means of a voltage divider (R.sub.3, R.sub.4) connected across the battery by means of a switch (S.sub.1) during the flyback intervals. To prevent the voltage drop across the internal resistance of the battery from influencing the measurement of the battery voltage, the battery voltage is measured after the end of a flyback interval and before the commencment of the next forward interval. This is achieved by short-circuiting the inputs (11, 12) of the protection circuit (10) by means of two diodes (D.sub.1, D.sub.2) during the flyback intervals.

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 translator 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 base voltage 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. A negative drive circuit is coupled between the feedback winding and the base of the switching transistor and supplies a constant negative bias voltage to the transistor base as energy is transferred from the inductor into a load.

Abstract: A single-ended, zero-current switching, forward converter circuit converts power from a current source to a voltage load in a succession of energy transfer cycles using a transformer constructed to have an effective leakage inductance L.sub.1e, a capacitor (C) in series with the primary winding of the transformer, a switching device also in series with the primary winding, a unidirectional conducting device connected in series with the secondary winding in an orientation to conduct when the switching device is conducting, and a controller that selectively closes and opens the switching device to transfer energy from the capacitor via the effective primary leakage inductance to the load during an energy transfer cycle having a characteristic time scale determined by L.sub.1e and C.

Abstract: A switched power supply has a rectifier arrangement for generating a DC voltage from an input AC voltage. A converter arrangement thereof has a switching transistor and a transformer. The converter arrangement is designed as a free-running flow converter wherein the switching transistor is switched on in a current-free condition. A secondary side of the converter arrangement comprises a secondary switch controller which is synchronized by the transformer and which regulates an output DC voltage.

Abstract: A switched power supply has a rectifier arrangement for generating a DC voltage from an input AC voltage. A converter arangement in the power supply has a switching transistor and a transformer. The converter arrangement is designed as a free-running flow converter, whereby the switching transistor is switched on in the current-free condition. A control stage with an electrically separated control loop is provided at the secondary side, whereby the control stage acquires the deviation of an output DC voltage from a prescribed value and sets the pulse duty factor for the switching transistor via the control loop.

Abstract: A power supply for an electrostatic air cleaner incorporates a high frequency oscillator and a step-up transformer. The transformer includes a primary winding in series with a transistor, a secondary winding which cooperates with a voltage multiplying means to produce a desired output voltage for energizing the cell, and a feedback winding. The feedback winding is connected in circuit with the emitter-base circuit of the transistor and is responsive to voltage induced therein for effecting repetitive conduction and non-conduction of the transistor. The feedback winding is further connected in circuit with circuit means for adjusting and limiting the biasing of the transistor.

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 DC-DC converter having a high conversion efficiency and stable output voltage. A constant current supply circuit, located between the output terminals of the converter, make it possible for the source current to decrease as a function of battery output voltage, resulting in lower current requirements for a lower required voltage boost and hence increased efficiency.

Abstract: A switching power source circuit intermittently switches a current at a primary winding of a transformer in accordance with the repeated switching of a bipolar transistor so as to rectify and smooth a voltage induced at a secondary winding of the transformer, thereby obtaining an output voltage. A capacitor is charged by a voltage induced by a feedback winding of the transformer. The base-emitter path of the bipolar transistor is reverse biased by this charge voltage so as to perform high-speed switching, so that a compact transformer and capacitor can be used and the switching power source circuit becomes low in cost.The application of the reverse bias voltage is performed by a transistor which is turned on when an emitter (grounded through a resistor) voltage of the bipolar transistor is increased to a predetermined level (threshold). A switching period of the bipolar transistor is determined by a period determining circuit consisting of a timing capacitor and a resistor.

Abstract: A control circuit is provided for operating a power switch with an associated resistance, wherein the power switch has conductive and nonconductive conditions and is adapted to apply a driving voltage across an electric load circuit, such as a D.C. motor, when the power switch is in its conductive condition.

Abstract: A magnetically controlled switching regulator which controls an output voltage using a saturable reactor, wherein the saturable reactor is constituted by a first winding through which an output current flows and a second winding through which a reset current flows. The energy for resetting the saturable reactor is supplied from a capacitor in a smoothing circuit for an output voltage. A turn ratio between the first and second windings is set so that a sufficiently high reset voltage is obtained. Since the reset current of the saturable reactor does not flow through a transformer, the saturation of the transformer and a high increase in temperature thereof do not occur, so that the core of the transformer can be miniaturized and a high gain of the output voltage control circuit can be derived.

Abstract: A power supply for an acoustic fuel injector (18) comprises a DC to DC converter (14) for supplying a regulated voltage to a frequency-controlled oscillator (16) which drives the injector valve or valves. The converter (14) comprises a flyback oscillator (28) including a switching transistor (32) and a transformer (34, 36) for applying rectified current pulses of variable amplitude and occurrence rate to an output capacitor (42). A variable impedance transistor (50) in the input circuit to the flyback oscillator (28) is controlled by a feedback signal (68) from the output circuit (30) to vary the cycle rate of the flyback oscillator (28) to maintain output voltage at a desired value. Start up of oscillations in flyback oscillator (28) is assisted by a resistive feedback connection (56) and oscillations are maintained by a tertiary transformer winding (38).

Abstract: In a power supply having transformer coupling for regulation of voltage by a pulsing of primary current, a control circuit integrates the output voltage to obtain a measure of flux and primary current. A comparator monitors the integrated voltage to terminate a pulse of primary current prior to saturation of a core of the transformer. This insures linear operation and efficient transfer of energy from the primary to the secondary windings of the transformer. A sensor of secondary current initiates a new pulse of primary current when the secondary current has decayed to a fractional value of the peak secondary current.

Abstract: A switching control circuit has a switching control transistor between a base current path of a switching power transistor and an emitter current limiting resistor. A collector current flows through the switching control transistor in the same direction as that of an emitter current flowing through the emitter current limiting resistor when the switching power transistor is held in an ON state. The direction of a current flowing through the emitter current limiting resistor does not change even if the switching control transistor is turned on so as to turn off the switching power transistor.

Abstract: A self-oscillating power converter utilizes a MOSFET power transistor switch with its output electrode coupled to a tuned network that operatively limits the voltage waveform across the power switch to periodic unipolar pulses. The transistor switch may be operated at a high radio frequency so that its drain to gate interelectrode capacitance is sufficient to comprise the sole oscillatory sustaining feedback path of the converter. A reactive network which is inductive at the operating frequency couples the gate to source electrodes of the transistor switch and includes a variable capacitance as a means of adjusting the overall reactance, and hence the converter's switching frequency in order to provide voltage regulation. A resonant rectifier includes a tuned circuit to shape the voltage waveform across the rectifying diodes as a time inverse of the power switch waveform.

Abstract: Adapter for field signals of computers, microprocessors systems or the like digital electronic circuits. The adapter receives either AC or DC signals, from external or field sources or from computers, microprocessor systems of the like digital electronic circuits, and provides AC or DC control voltages to external or field controls or to computers, microprocessor systems or the like digital electronic circuits. The adapter includes a first switching circuit which responds to the level of an input signal, and which actuates an oscillator which includes the primary of a transformer as its load. Energy is transferred by the transformer secondary to appropriate control circuits for use elsewhere. The adapter also includes a second switching circuit which also responds to a different level of the input signal, the second switching circuit diverting the input signal current into itself across an artificial load when the first switching circuit is inoperative.

Abstract: A self-excited switching type D.C. power supply for producing a stabilized output signal. The power supply is provided with a rectifier, a primary winding of a transformer, a switching transistor and a resistor connected in series with one another between first and second input terminals of the power supply. The transformer is further provided with a secondary winding, a Zener diode, a capacitor and a resistor connected in series with a photocoupler. The photocoupler is connected in series with a pair of control transistors which control the operation of the switching transistor. The switching frequency of the switching transistor is stabilized by providing a quiescent time period during which the switching transistor is disabled.

Abstract: A d.c.-a.c. inverter circuit allows a standard type fluorescent lamp to be operated from a low-voltage source of d.c. power with a high degree of efficiency attributable in part to use of lamp current as base drive current for a power transistor controlling the energization of a transformer primary winding having two mutually connected secondary windings which apply voltages across the lamp through the power transistor. Additional efficiency is achieved by use of a second transistor under time delay control for supplying preheat current to the lamp and turn-on current to the power transistor only during the starting phase of lamp operation.

Abstract: A high power efficiency drive system for a DC motor which controls the supply of power to polyphase coils has a DC-DC switching converter for changing an output voltage according to an ON-time ratio of the switching transistor, and a switching controller for controlling the ON-time ratio of the switching transistor. The DC-DC switching converter includes a switching transistor for chopping the voltage of a DC voltage source, a filter for smoothing the output voltage of the switching transistor, and a current amplifier for supplying the switching transistor with a base current pulse having a magnitude proportional to an input current. The switching controller controls the operation of the current amplifier for producing the base current pulse of the switching transistor.

Abstract: A high voltage power supply is formed by three discrete circuits (12, 14, 16) energized by a battery (18) to provide a plurality of concurrent output signals floating at a high output voltage on the order of several tens of kilovolts. Each circuit has a regulator stage (20, 28, 36). In the first two circuits, the regulator stages are pulse width modulated and include adjustable resistances (R1, R2) for varying the duty cycles of pulse trains provided to corresponding oscillator stages while the third regulator stage includes an adjustable resistance (R3) for varying the amplitude of a steady signal provided to a third oscillator stage.

Abstract: A stabilizing power-supply circuit adapted to apply the output signals of a comparison amplifier directly upon the base circuit of the oscillation transistor of an oscillating circuit through a zener diode. The oscillation is reduced to a given output voltage during the no-load thereby to protect the power-supply apparatus.

Abstract: A circuit arrangement for the controlled supply of loads, in particular portable devices, for example dry razors and electronic flash devices, or also fluorescent lamps or the like, on virtually any d.c. and a.c. systems of different frequencies and voltages, without switching over. For that purpose, the arrangement uses a blocking converter (5) which is controlled by means of two controllable semiconductor switches (T1, T2) in dependence on the current (I1) flowing through the primary winding (n1) of the converter (5) and in dependence on the input voltage (U1) of the supply, in such a way that the output power supplied follows a desired characteristic curve and in particular is constant. If the load to be supplied is an accumulator (2) with a motor (1) connected in parallel, the circuit arrangement can supply either the full motor power or, when the motor is switched off, a charging current for the accumulator (2).

Abstract: A self-referencing self-oscillating power converter is disclosed. The power converter operates in the flyback switch mode to convert a high voltage DC power source to low voltage regulated power supply voltages applied to a load. Energy is stored in a primary winding of a power transformer during energy store cycles by causing a current to flow in the primary winding. This current is interrupted and the stored energy is delivered across the transformer to the load during an energy transfer cycle. The converter includes means for sensing the current in the primary winding at low voltage potentials, and for controlling the duration of each energy store cycle in response to the level of current in the primary winding to deliver the power required to drive the load at the regulated voltages.

Abstract: A battery power indicator for a DC to DC flyback converter is responsive to the current flowing in the secondary winding of the converter's transformer. In one embodiment the power indicator is lighted when the battery is weak but not dead. If the battery is good, the indicator is bypassed and remains off. In a second embodiment, the indicator is lighted to indicate a good battery and when the power capability of the battery drops below a predetermined level, the indicator turns off.

Abstract: A power supply circuit of switching regulator type includes a converter transformer defined by a first winding for receiving input power from a DC source and second winding for producing output power. A switching transistor is connected to the first winding for alternately making and breaking electric connection between the DC source and the first winding by alternate turn on and off operations of the switching transistor, and a rectifier is connected to the second winding for rectifying the output power. A first detector is provided for detecting the rectified output DC voltage during off-period of the switching transistor and for producing an output-voltage signal representing the output DC voltage. A power supply circuit further includes a second detector for detecting the input DC voltage during on-period of the switching transistor and for producing an input-voltage signal representing the input DC voltage.

Abstract: A switched-mode self-oscillating supply voltage circuit for converting an input voltage into an output d.c. voltage which is substantially independent of variations of the input voltage and/or a load connected to the output voltage. The circuit comprises a first controllable switch connected in series with a transformer winding and a second controllable switch for turning-off the first switch. The conduction period of the first switch is controlled by means of a control voltage present on a control electrode of the second switch. The circuit can be switched-over to a stand-up state in which the energy supplied to the load is reduced to zero. A starting network is connected between the input voltage and the second switch so that the current therein flows through the second switch during the period of time this switch conducts and does not flow to the control electode of the first switch in the stand-by state.

Abstract: A ringing converter of the type having an output voltage stabilizing circuit connected on the primary side of a transformer. The converter is further provided with a circuit for detecting the primary current, which is proportional to the load current on the secondary side of the transformer. This enables detection of a change in the output voltage due to fluctuation in the load current on the secondary side, as detected by the detecting circuit. A signal indicative of the detected change is fed back to an oscillator circuit in order to stabilize the output voltage.

Abstract: A power supply circuit comprises a main transformer having a primary winding and a secondary winding, a series resonance circuit coupled to the primary winding of the main transformer, and a switching circuit for alternately supplying DC power to the series resonance circuit and discharging the energy stored therein. A current protection circuit controls the switching circuit in dependence upon the current in the switching circuit and a voltage protection circuit controls the switching circuit in dependence upon the voltage of the secondary winding of the main transformer.

Abstract: A clamp device for a switching transistor of a D.C. to D.C. converter is non-conductive when the converter is ON. When the converter is turned OFF, the clamp device is placed in a standby state that clamps off the switching transistor and draws no power from the battery. When noise occurs the clamp device momentarily enables the converter, but only while such noise is present.

Abstract: A switching regulator having a blocking oscillator including a transistor, and a transformer with primary, secondary, and positive feedback windings. A rectifying and smoothing circuit is connected to the load and includes a photodiode coupled to a phototransistor connected to the blocking oscillator transistor in the feedback path for adjusting feedback to maintain output voltage at a constant level. A second positive feedback circuit connects between the phototransistor and the blocking oscillator transistor to assure stable oscillation of the blocking oscillator.

Abstract: A battery charger includes a transistor inverter. The transistor inverter includes an oscillation transformer and a switching transistor for controlling a current flowing through a primary coil of the oscillation transformer. This current charges the battery when the transistor is on. While the switching transistor is in an off state, charging current is supplied to the battery from a secondary coil of the oscillation transformer. The period of time where the switching transistor is in an on state is controlled depending on the amplitude of a supply voltage. Accordingly, the average value of a charging current to the rechargeable battery is automatically kept substantially constant despite variations in the amplitude of the alternating current voltage supply.

Abstract: A switching regulator is disclosed which is designed so that a negative feedback is applied to the base of a transistor constituting an oscillator adapted for chopping a DC voltage, only during a period of time which is required to effect pulse width control when the transistor is switched from conduction to non-conduction. A control circuit may also be provided which is arranged to compare the output of a current detecting circuit for detecting a current proportional to a current for driving a transformer with the output of an error voltage amplifier for amplifying an output resulting from comparison of a rectified version of the AC output of the transformer with a reference voltage. The foregoing control circuit is also arranged so that when the output of the current detecting circuit exceeds the output of the error amplifier, a trigger signal is imparted to cause the oscillator to be changed from the on state to the off state.