The scenario
A field-service technician needs a safe, battery-powered handheld tester to detect live AC wiring without making galvanic contact.
What is in this drawing
Read the decisions behind it.
01
Use a high-impedance capacitive probe input to avoid loading the circuit under test
02
Use a charge-pump detector to produce a DC level proportional to field strength
03
Use a resistive divider from the 9V battery to set three LED bar thresholds
Any non-contact live-line verification, outlet testing, or cable tracing where direct contact is unsafe or impractical.
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