Principles of Operation
The Electroding Generator is a low frequency oscillator with a sine
wave output capable of delivering up to 500mA at 500 Volts peak to
peak at any frequency from 5Hz to 99.9Hz.
The frequency is selected by
digital thumbwheel switches, Peak current is set via a front panel
rotary control.
The Current and Voltage levels are clearly displayed
on Front Panel Precision Analogue Meters.
The current waveform is controlled to be sinusoidal. The test
current has a DC bias to improve the sensitivity detection over longer
distance. The test current can be applied in either the forward
direction only or in the reverse or forward bias, as required. Longer
cable can normally be electroded by energizing in the reverse
direction. A crystal controlled oscillator ensures that the frequency
does not drift while testing is in progress.
Output connections are made by permanently connected probes, which
are fully shrouded.
A safety circuit disables the Generator output
whilst the probes are being applied to the cable under test.
A special
compartment on the rear of the instrument is provided for stowing the
output probes when not in use.
A frequency monitor point (square wave at signal frequency) is
provided on the rear on the instrument. Output level is TTL
compatible.
