TOS3200
185
Four Principal Tests for Evaluating the Safety of Electrical and Electronic Products
Appx
Fig. A-1 Leakage current test 2
Typical example of TC measurement
Fig. B-6 Body impedance network
A body impedance network is connected in place of an actual human body, and the current
flowing through the network is measured. In some cases, the TC between the enclosure and
the power line or that between the enclosure and another enclosure is also measured in addi-
tion to the TC between the enclosure and ground.
Reference
Fig. B-7 Example of a body impedance network
N
L
PE
Z1
Z2
Enclosure
Electronic Equipment
Secondary
Primary
Power
supply
Accessible conductive part
Test not only when the PE or power line
is normal but also when it is broken.
The polarity of the power line may be
reversed in some tests.
Isolation transformer (arbitrary)
Touch current between the
enclosure and ground
A
Input A
Input B
Body impedance network
Input A
Input B
Measure voltage U across here
Calculate using touch current I = U/500
1.5 kΩ
500 Ω
10 kΩ
0.22 µF
0.022 µF
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