The invention relates to a resonant converter (200, 300). The resonant
converter (200, 300) consists of a first circuit, primarily a DC circuit
(201, 301) connected to a resonant circuit (207, 307) which is further
connected to a switch/filter circuit (212, 312) which is connected to a
second circuit, primarily an AC circuit (219, 319). The proposed resonant
converter (200, 300) is unique in that the resonant converter (200, 300)
contains a direct connection between a voltage center (203, 303) in the
DC circuit (201, 301) and a voltage center (209, 309, 325) in the
resonant circuit (207, 307), and that the resonant circuit (207, 307)
contains at least one transformer having at least two windings (223, 224, 331,
332, 333, 334), wherein there is a connection from the windings (223, 224,
331, 332) of the transformer to at least first and second switches (215,
216, 315, 316, 328, 329), wherein activation of the switches (215, 216,
315, 316, 328, 329) forms a connection to at least a first node (214, 314,
327), wherein a voltage center (203, 303) in the DC circuit (201,
301) is also connected to the first node (214, 314, 327) by activation
of at least a third switch (213, 313, 326). This results in a resonant converter
(200, 300) wherein there are just switches (213, 215, 216, 313, 315,
316, 326, 328, 329) in the switch/filter circuit (212, 312) so that
the number of switches (213, 215, 216, 313, 315, 316, 326, 328, 329) with
power loss is as low as possible. The resonant converter (200, 300) moreover
has the advantage that there is a direct connection from the center (203, 303)
of the DC circuit (201, 301) to the load (219, 319), without this
current path running through the coil (217, 317, 330) to the resonant circuit
(207, 307). This minimizes the current load of the coil (217, 317, 330)
and hereby the influence on the frequency of the resonant converter in case of
a short-circuit on the output of the resonant converter (200, 300) where
a great output current is to be provided, while the output voltage is close to
zero volt. The reason is that a switch (213, 313, 326) in the switch/filter
circuit (212, 312), which is connected to a voltage center (214, 314,
327), will conduct for by far the greatest part of the time at an output voltage
close to zero volt, and that this current path bypasses the resonant circuit (207,
307). In addition, reduced switching across the switches (213, 215, 216,
313, 315, 316, 326, 328, 329) is achieved.