V
OLTECH
AC
I
NTERFACE
U
SER
M
ANUAL
98-072
ISS
7
PAGE
17
1.6. O
PERATING
D
ESCRIPTION
The basic power circuit of the AC Interface provides connections on 4mm sockets for the output of the chosen
source, a series current sensing device and output to the winding under test.
Test current flows from the external source into the fixture and out to the winding under test via an isolation
relay.
The current returns through the fixture via another relay and a current sensing transformer or shunt that must
be fitted to the interface.
A standard 1:20 current transformer is supplied with each interface which should be suitable for most
applications.
The
’CT Input’
sockets on the fixture should be connected to the secondary of the current transformer, so that
the AT3600/AT5600 can measure the current in the winding under test. When a resistive shunt is used, the
'Shunt Sense' sockets provide a voltage output that is proportional to the current. These terminals must be
connected to nodes 17 and 19 of the AT3600/AT5600 if a resistive shunt is used.
The
’AT Transformer Drive Output’
sockets are used to drive a step-up or step-down transformer when that
type of source has been chosen.
The cable fitted to the
’AT Peripheral Port’
gland must be fitted to the peripheral port of the AT3600/AT5600.
This port supplies power and control signals to the AC Interface.
Control signals for an external source are available on the connecter next to the gland marked
’To AC
Source.’
Full details of each function are contained in the technical information section of this manual
Input from
External
Source
Output to
Winding
Under Test
Current Transformer (CT) or
Shunt
i
