Method and circuit arrangement for operating light-emitting means with a sudden load variation

摘要

An operating circuit for light-emitting means (18), in particular an LED string, contains an actively clocked power factor correction circuit (11), which produces a regulated output voltage (UBUS), by means of which the light-emitting means (18) are supplied directly or indirectly via at least one further converter stage (17). The regulation is performed by means of a control unit (16), which, as manipulated variable (tON), actuates clocking of a switch of the power factor correction circuit (11). The operating circuit is designed, in the event of the presence of a predefined event, for example a rapid or sudden change in the energy demand of the light-emitting means (18), selectively: —to change suddenly the value of the manipulated variable (tON) using feedforward control, and/or —to vary the time constant of the control loop of the output voltage (UBUS).

主权项

1. An operating circuit for light-emitting means (18) comprising an actively clocked power factor correction circuit (11), which generates an output voltage (UBUS) controlled using a control loop, by means of which output voltage the light-emitting means (18) are supplied indirectly via at least one further converter stage (17),
wherein the control loop has a control unit (16), which, as manipulated variable (tON), drives the clocking of a switch of the power factor correction circuit (11), wherein the control unit is configured, in the event of the presence of a predefined event selectively:
to vary the value of the manipulated variable (tON) suddenly with feed-forward control, orto vary the time constant of the control loop of the output voltage (UBUS); and wherein the control unit (16) is configured to increase the value of the manipulated variable (tON) suddenly with feed-forward control in the event of the presence of a rapid or sudden increase in the energy requirement of the light-emitting means (18), and to reduce the value of the manipulated variable (tON) suddenly with feed-forward control in the event of the presence of a rapid or sudden reduction in the energy requirement of the light-emitting means (18).