Atec Chroma-19032 - Manual (Page 2)

OSC function is used to check if the connection is open (bad contact) or short (DUT short) during the test procedure. When circuit opened during
the test, NG product will be judged as good product. When short occurred during the test, screening earlier can reduce the damage on equipment .
Generally speaking, the DUT has capacitive load (Cx) from tens of pF to several uF in normal state. A micro capacitance will occur on an open
circuit interface, once the connection is interrupted (as Cc in figure 2). In general, the capacitance is lower than 10pF ; thus the total capacitance is
far lower than the normal product. The capacitance is far higher than normal when the DUT short or close to short. Therefore, users can judge the
short problem by using the high/low limit value of capacitance change.
TWINPORT TM HIPOT & GROUND BOND TEST FUNCTIONS (USA PATENT NO.: US6504381)
FLASHOVER DETECTION
OPEN / SHORT CHECK (OSC) (PATENT 254135)
CAPABILITY OF CONTROLLING CHROMA AC SOURCE (6400 / 61600 / 61500 SERIES)
The manufacturers apply Chroma AC Source as the power supply to increase the input voltage stability for
dynamic leakage current test. The 19032 uses RS232 interface to control the AC Source related models that
make the dynamic leakage current test more convenient.
Measurement Technology
Figure 1 : Normal Leakage Current Waveform Figure 2 : Leakage Current Waveform when flashover occurred
Figure 1 : Normal Connection Figure 2 : Connection Open Figure 3 : Connection Short
The 19032 electrical safety tester has Twinport™ Technology. This patent and
unique feature are allow to test Hi-pot and ground bond simultaneously. It can
reduce half of the time on testing;so it is ideal for production test.
The 19032 has Flashover Detection as other Chroma safety test series. Flashover is electricity transient or non-sequential discharge generated by
the inner or surface of insulation component which cause DUTs to lose original insulation feature,generated carbonation electrically conductive path
and damages the product . Test voltage or shift rate of leakage current is required. As flashover cannot be detected by leakage current, Flashover
Detection is one of inevitable inspection items in HV test.
Conventional
Safety
Analyzer
19032
Ground Bond Hipot
Ground Bond
Hipot
2 Sec. 2 Sec.
10
-10
Test Voltage Waveform
Gap Discharge Voltage
180 360
Leakage Current (normal capacitive)
0
10
-10
Test Voltage Waveform
Gap Discharge Voltage
180 360
Leakage Current (abnornmal with flashover)
0
V
s
V
µA
Hi
Lo
C
x
V
µA
Hi
Lo
C
c
V
s
C
x
V
µA
Hi
Lo
V
s