29
Technical information
and start-up
BSC624-12V-B
6.4.4
HV filter concept
Component
Value
Unit
C
y1
6.6
nF
L
h
2314.0
µH
L
s
5.8
µH
C
y2
15.0
nF
C
b
16.2
µF
The HV choke located at the input is generally of the common-mode choke type (L
h
). However, it also helps to
filter the differential mode interferences by means of the existing leakage inductance (L
s
).
The wired Y capacitors (C
y2
) together with the common-mode choke (L
h
) form the common-mode filter.
In order to filter particular high-frequency common-mode interferences, Y capacitors (C
y1
) with very low
impedance are directly connected at the input.
The intermediate circuit capacitor (C
b
) together with the leakage inductance of the HV choke (L
s
) forms the
differential mode filter. Due to the high clock frequencies, the capacitor may have very small dimensions.
Thus, a rapid discharge of the intermediate circuit is possible.
