US 6,285,566 B1 · RCC power supply with remote disabling of oscillation frequency control

Abstract

A self-oscillation switching power supply apparatus of the ringing choke converter type comprises a transformer T including a primary winding N1, a secondary winding N2, and a feedback winding NB; a switching transistor Q1 which oscillates in a self-oscillating fashion in response to a feedback signal from the feedback winding NB thereby turning on and off the current flowing through the primary winding; a rectifying and smoothing circuit connected to the secondary winding; an oscillation frequency control circuit including a control transistor Q3 for controlling a control signal input to the switching transistor Q1 thereby controlling the control transistor Q3 so as to extend the off-time in the self-oscillation period of the switching transistor Q1; and an oscillation frequency control disabling circuit for disabling the control of the control transistor Q3 in accordance with a remote signal.

Claims18

Dependent claims

A self-oscillation switching power supply apparatus of the ringing choke converter type comprising:

a transformer including a primary winding, a secondary winding, and a feedback winding;
a switching transistor which oscillates with a self-oscillation period so as to have an on-time and an off time in response to a feedback signal from said feedback winding thereby turning on and off current flowing through said primary winding;
a rectifying and smoothing circuit connected to said secondary winding;
an oscillation frequency control circuit including a control transistor for controlling a control signal input to said switching transistor and a capacitor to be charged by a voltage induced across said feedback winding, the oscillation frequency control circuit controlling said control transistor in response to discharge of the capacitor so as to extend the off-time in the self-oscillation period of said switching transistor;
and
an oscillation frequency control disabling circuit for disabling the control of said control transistor in accordance with a remote signal.

3 more elements

A method of controlling a self-oscillation switching power supply apparatus of the ringing choke converter type wherein the switching power supply has a transformer including a primary winding, a secondary winding, and a feedback winding;

a switching transistor which oscillates with a self-oscillation period so as to have an on-time and an off-time in response to a feedback signal from said feedback winding thereby turning on and off current flowing through said primary winding;
and a rectifying and smoothing circuit connected to said secondary winding;
the method comprising steps of:
providing a further control of said switching transistor by providing a control signal to a control input of said switching transistor from an oscillation frequency control circuit including a capacitor to be charged by a voltage induced across said feedback winding;
controlling the control signal input to said switching transistor in response to discharge of said capacitor so as to extend the off-time in the self-oscillation period of said switching transistor;
and
selectively disabling the further control in accordance with a remote signal.

4 more elements

Dependencies are inferred from the claim text.

RCC power supply with remote disabling of oscillation frequency control

Life of this patent

RCC power supply with remote disabling of oscillation frequency control

Life of this patent

Abstract

Claims18