Abstract: In a switching mode power supply, an input received from the secondary side of the transformer 7 and indicative of the power being drawn by the loads is used to control the timing of bursts. The input is compared with two threshold different threshold values V2, V3, and switching is enabled if the input rises above a first higher threshold value V2, and disabled if it falls below a second lower threshold value V3. A memory device FF1 controls a current limitation circuit which limits currents in the primary of the transformer when the switching mode power supply is operating in the burst mode.

Abstract: The invention relates to an actuation circuit for a switch (SW) controlling the power consumption in a switch-mode converter which has input terminals (K1, K2) for applying an input voltage (Vin) and output terminals (K3, K4) for providing an output voltage. The actuation circuit (100) comprises a first input (K11) for supplying a voltage measurement signal (Vs) which is dependent on the output voltage (Vout), an error signal generation circuit (10) which generates an error signal (S10) by comparing the voltage measurement signal (Vs) with a reference signal (Vref), a filter arrangement (20) which is supplied with the error signal (S10) and which generates a first control signal (S1), and an actuation signal generation circuit (30) which is supplied with the first control signal (S1) and which provides an actuation signal (PWM) for the switch (SW) on the basis of the first control signal (S1).

Abstract: A switched mode power supply includes a primary coil, a switch element, a secondary circuit, and a control circuit. The switch element is wired in series with the primary coil, for applying a DC voltage to the primary coil according to a control signal. The secondary circuit is coupled to the primary coil with output terminals providing an output voltage. The control circuit prepares the control signal with a feedback signal dependent on the output voltage supplied to the control circuit. The control circuit includes a signal generation circuit to create the control signal and a protection circuit. The protection circuit has the effect that no control signal is delivered to the switch element, if the feedback signal reaches the value of a first reference signal after a first period after starting the control circuit.

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

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

Abstract: A switched mode power supply includes a primary coil, a switch element, a secondary circuit, and a control circuit. The switch element is wired in series with the primary coil, for applying a DC voltage to the primary coil according to a control signal. The secondary circuit is coupled to the primary coil with output terminals providing an output voltage. The control circuit prepares the control signal with a feedback signal dependent on the output voltage supplied to the control circuit. The control circuit includes a signal generation circuit to create the control signal and a protection circuit. The protection circuit has the effect that no control signal is delivered to the switch element, if the feedback signal reaches the value of a first reference signal after a first period after starting the control circuit.