Tektronix TCP300A, Руководство пользователя

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Application Notes
High-Impedance Pulse
Sources
If the pulse source has a higher impedance of known resistance, such that the
output voltage drops as the current increases, the inductance of a coil can be
calculated by the time constant of the charge curve. The current ramp shows how
the values for the inductance formula are obtained. (See Figure 23 on page 39.)
Use this formula to calculate the inductance based on the current measurement:
where L is the inductance in henries, τ is the time required for the current to rise or
fall 63.2% of the total current value, and R is the source resistance of the pulse
generator.
Figure 23: High-impedance source current ramp
Continuity Test of Multiple-Conductor Cable
Single conductors in a multiconductor cable can be tested with the TCPA300 and
TCPA400. To check a conductor, clamp the current probe around the cable bundle
and check for a speci
fi c, known current signal. If there is no current or the current
is abnormally low, then the conductor has a continuity problem. If the current is
abnormally high, then the conductor may have a short to ground.
TCPA300/400 Ampli fi ers and TCP300A/400 Series Current Probes User Manual 39