Friwo Mobile Power Gmbh

Power Systems Technologies Gmbh

Flextronics Ap, LLC

Flextronics Gmbh & Co Kg

Ralf Schröder Genannt Berghegger

Reinhold Schulz

Florian Schäfer

Systems and methods ('utility') are provided for reducing the no-load (standby) power of power devices such as chargers for electronic devices and power converters for electronic devices. The utility may include a controllable switch that is operative to decouple circuitry of the power device from a power source under certain no-load conditions. In one embodiment, the utility provides a switch control module that is operative to sense when an electronic device is coupled to the power device, and in response, to control the switch to couple the power device to the power source. The switch control module may also be operative to detect a condition when the electronic device is no longer drawing power from the power device, and in response, to control the switch to decouple the power device from the power source.

Techniques for reducing no load power in electronic devices

A power converter with reduced power dissipation at light loads and method of operating the same. In one embodiment, the power converter includes an opto-isolator circuit configured to produce an output signal dependent on an output characteristic of the power converter. The power converter also includes a controller configured to control the output characteristic to a first regulated value when the output signal is greater than or equal to a threshold level, and control the output characteristic to a second regulated value less than the first regulated value when the output signal is less than the threshold level.

Power converter with reduced power dissipation

The present invention relates to a trigger circuit for a switch in a switching power supply, especially in a primary-side, triggered switching power supply. The trigger circuit here comprises a feedback signal terminal for detecting an auxiliary voltage induced on a primary-side auxiliary winding of a transformer of the switching power supply, a supply voltage terminal for supplying the trigger circuit with a supply voltage, and a ground terminal for connecting the trigger circuit to a ground potential, wherein the feedback signal terminal is formed by the supply voltage terminal and the auxiliary voltage is superimposed on the supply voltage. Alternatively, the voltage of the auxiliary winding could be superimposed on the voltage on an additional pin that is used for detecting the primary peak current.

Simplified primary triggering circuit for the switch in a switched-mode power supply

A control circuit and method for controlling the output voltage and/or the output current of a switching power supply. The control circuit includes a transformer with a primary-side and a secondary-side main winding and a primary-side switch for switching on and off the primary current through the primary-side main winding in response to a control signal of the control circuit. The control circuit also includes a primary-side auxiliary winding operable to induce a voltage pulse after the primary-side switch is turned off, and a sample and hold device for sampling and storing a level of the voltage pulse for generating a control variable.

Control circuit for current and voltage control in a switching power supply

This invention relates to a control circuit for the closed-loop control of an output voltage of a primary-controlled switched-mode power supply as well as an associated method. The switched-mode power supply comprises a primary-side switch and a transformer with at least one auxiliary winding in which an auxiliary voltage is induced after opening the primary-side switch. The voltage induced in the at least one auxiliary winding provides the basis for the measurement voltage passed to the control circuit and for the supply voltage of the control circuit. The invention also refers to an associated switched-mode power supply. In order to overcome the problems of known control circuits and to provide an improved control circuit for a primary-controlled switched-mode power supply, which can be constructed with increased control accuracy, but nevertheless with a small size and low component costs, the control circuit comprises a measurement voltage connection for connection to the measurement voltage and a supply voltage connection separate from same for connection to a supply voltage which is produced from the auxiliary voltage.

Switched mode power supply having a control circuit for setting the switching frequency of the primary side switch in a linear relationship to a measurement voltage produced from the auxiliary voltage

The present invention relates to a method for controlling the output voltage of a primary-controlled switched-mode power supply unit having a primary-side switch and a transformer with an auxiliary winding in which an auxiliary voltage which images the output voltage is induced after the primary-side switch is opened. The voltage induced in the auxiliary winding is fed to a control circuit as the control variable. The present invention also relates to a control circuit for performing such a control method and to an associated switched-mode power supply unit. To adjust the output voltage and the output current in the simplest and most economical way while minimizing the cost of the components needed, the switching frequency of the primary-side switch is so adjusted in dependence on the auxiliary voltage in the present invention that the output voltage and the output current of the switched-mode power supply unit adopt values in accordance with a predetermined output characteristic. This may be a linear output characteristic.

Primary-controlled SMPS with adjustable switching frequency for output voltage and current control

This invention relates to a primary-controlled switched-mode power supply of the type of a free-running flyback converter, which comprises a transformer with a primary-side winding, a secondary-side winding and at least one auxiliary winding. The switched-mode power supply comprises a primary-side switch, which is connected to the primary-side winding, in order to interrupt a current flow through the primary-side winding, a freely oscillating circuit for the generation of switching pulses, which drive the primary-side switch, and a circuit for generating an image voltage between the terminals of the auxiliary winding, in order to generate an image voltage, which on the primary side forms a voltage to be regulated on the secondary side. In order to provide a switched-mode power supply of this type, which with reduced complexity enables an improved control characteristic and an increased flexibility with regard to the operating parameters, the switched-mode power supply further comprises a time control unit, which is coupled to the primary-side switch such that the duration of a turn-off period of the primary-side switch can be adjusted within a switching cycle.

Simple switched-mode power supply with current and voltage limitation

A control circuit for controlling the output voltage of a primary-controlled switched mode power supply. The switched mode power supply includes a primary-side switch and a transformer with a primary winding, a secondary winding and a secondary-side auxiliary winding. The control circuit is connected to the auxiliary winding and a voltage tapping point between the secondary winding and the auxiliary winding. The control circuit includes a secondary-side switch and an RC element. The secondary-side switch short-circuits the connection between the output terminal and the voltage tapping point and the RC element provides positive and negative control pulses having a predefined time constant.

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Glandorf, Germany

Ralf Schröder Genannt Berghegger