US 12,324,067 B2
Lamp driver with voltage sensing
Tijmen Cornelis Van Bodegraven, Eindhoven (NL); and Reinhold Elferich, Aachen (DE)
Assigned to SIGNIFY HOLDING B.V., Eindhoven (NL)
Appl. No. 18/017,747
Filed by SIGNIFY HOLDING B.V., Eindhoven (NL)
PCT Filed Jul. 26, 2021, PCT No. PCT/EP2021/070812
§ 371(c)(1), (2) Date Jan. 24, 2023,
PCT Pub. No. WO2022/023243, PCT Pub. Date Feb. 3, 2022.
Claims priority of application No. 20188108 (EP), filed on Jul. 28, 2020.
Prior Publication US 2024/0015867 A1, Jan. 11, 2024
Int. Cl. H05B 45/382 (2020.01); H05B 45/00 (2022.01); H05B 45/10 (2020.01); H05B 45/3725 (2020.01); H05B 45/385 (2020.01)
CPC H05B 45/382 (2020.01) 10 Claims
OG exemplary drawing
 
1. A lamp driver comprising:
a transformer;
a primary side circuit including a primary side winding of the transformer; and
a secondary side circuit including a secondary side winding of the transformer, isolated from the primary side circuit, the secondary side circuit for delivering an output voltage and an output current to a lamp load,
wherein the primary side circuit comprises:
a half bridge circuit having a high side transistor and a low side transistor with a node between them;
a controller for controlling the switching of the high side and low side transistors; and
a sensor circuit for measuring a conduction time or switching frequency of the high side transistor or the low side transistor,
wherein the controller is adapted to derive an estimate of the output voltage from the measured conduction time or switching frequency,
wherein the controller is adapted to derive the estimate of the output voltage using a pre-determined transfer function relating the conduction time or the switching frequency to the output voltage together with the output current and/or a supply voltage (VBUS) within the primary side circuit.