Joy-it T7 - Page 8

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7. PROBLEMS
The JT-LCR-T7 is not a professional measuring device, and due to the
wide variety of components available in the market, it cannot be
guaranteed that all components will be correctly identified.
Please note that the JT-LCR-T7 is primarily designed for small-signal
components and the maximum measuring current is usually around 6
mA. When dealing with power semiconductors, diiculties may arise in
identifying or measuring the junction capacitance due to high residual
currents. For thyristors and triacs, the trigger and holding currents are
oen not suicient, leading to misidentifications such as recognizing a
thyristor as an NPN transistor or diode. There are also instances where a
thyristor or triac may not be identified at all. Similar challenges occur
with semiconductors that have built-in resistors. For example, the
base-emitter diode of a BU508D transistor oen goes unrecognized due
to an internally parallel-connected 42Ω resistor, making it impossible to
test the transistor function. High-power Darlington transistors, which
also have base-emitter resistors, can likewise be diicult to identify,
especially given the small measuring currents used by this device.