US Patent No. 10,602,594

DRIVE CIRCUIT FOR A FLASH TUBE AND A METHOD FOR CONTROLLING THE DRIVE CIRCUIT


Patent No. 10,602,594
Issue Date March 24, 2020
Title Drive Circuit For A Flash Tube And A Method For Controlling The Drive Circuit
Inventorship Johnny Svensson, Sollentuna (SE)
Assignee PROFOTO AB, Sundbyberg (SE)

Claim of US Patent No. 10,602,594

1. A drive circuit for a flash tube comprising:a capacitor;
a first inductor switch group comprising a first inductor and
at least one first switch connected in series with each other, the first inductor switch group being configured to be connected in series with the flash tube and the capacitor;
a control unit comprising receiving means for receiving at least one input parameter related to a desired flash characteristics; and
a second inductor switch group comprising a second inductor and a second switch connected in series with each other,
the second inductor switch group being configured to be connected in series with the flash tube and the capacitor, and being connected in parallel with the first inductor switch group,
wherein the control unit is configured to control the first and second inductor switch groups separately based on the at least one input parameter to obtain the desired flash characteristics, and
wherein each inductor switch group is associated with a preset maximum current, the control unit being configured to, based on the input parameter:
determine a flash current required to be fed to the flash tube in order to achieve the desired flash characteristics,
determine, based on the determined flash current, a switch algorithm used to ensure that no individual inductor switch group has to carry an electric current exceeding the preset maximum current of that inductor switch group, and
use the determined switch algorithm to feed the flash current to the flash tube.