4.2 Basic Principle
Constant-current AC testing uses the normal VOCX test to control the
current and make the secondary voltage measurement.
- The current to be controlled, I, is converted to a voltage, V, by
means of a current-sensing resistor, R.
- The voltage, V, is connected to the sense terminals of the AT3600,
which would normally be used to measure the energizing voltage.
- In the PC Editor, the voltage, V, is used as the energized voltage.
- When VOCX is performed, the AT3600 will trim the source, such that
the desired current is provided, I = V / R.
- The transformer secondary voltage is measured in the normal way as
the result of the VOCX test.
- The AT3600 adjusts the source voltage to maintain a constant ac
current through resistor, R.