S.P.L. HF-400, Руководство пользователя

Страница: 9 / 27

S.P.L.
HF-400 User manual
9
4.1 Physical fundamentals of the power measurement at electro surgery
units
Power output P
L
of electro surgery units is, as it is with all electrical generators, the
product of the voltage U
L
at the load resistor R
L
and the current I
L
by the load resistor
R
L
.
(1)
P
L
= U
L
x I
L
I
L
and U
L
are dependent, as it is shown in the alternate circuit diagram, on the
internal resistor R
i
of the surgical device and from the neutral voltage U
0
from the
HF-generator within the HF surgical device
:
(2) I
U
R R
L
i L


0
(3) U I R
U
R R
R
L L L
i L
L
  


0
If you take the right sides of the equations (2) and (3) and put them in equation (1),
then the dependence of power output P
L
from the electro surgery units on internal
resistor Ri and on the load resistor R
L
is recognizable:
(4) P
U
R R
R
L
i L
L







 
0
2
electrosurgery units
R
i
U
0
I
L
U
L
R
L