4.7.1
Isolation Tranformer and Power Supply
The Isolation Tranformer and Power Supply are
mounted at the base of the trolley.
The Line and Neutral mains entering the inlet are
fused with F1 and F2, followed by a double pole
on/ off switch “S1”. Two 2R5 inrush current
suppressing thermistors TH1 and TH2 are used in
line to limit the high initial current drawn by the
torroidal isolating transformer.
The toroidal transformer “T1” has an inbuilt
over-temperature cutout switch, which will reset
once the tranformer has cooled.
The mains input Voltage selector switch “S2”
switches the pair of primary windings in series for
200V-240V and in parallel for 100V-120V
operation.
The outputs of the pair of secondary winding is
passed through filters FM1 and FM2.
The mains ouput Voltage selector switch “S3”
switches the pair of secondary windings in series
for 200V-240V and in parallel for 100V-120V
operation.
The terminal block TB2 also provides isolated
mains voltage to the eight outlets.
Terminal block TB2 provides isolated mains
voltage to the three power supply modules. The
table below gives the voltages and maximum
output currents, the voltages can be measured at
connector 15 way D type socket K30.
DC PSU
VOLTS
OUTPUT
K30
PIN No.
AMPS
PSU1
+12V
7, 14
1A
0V12
3, 11
-12V
2, 10
1A
PSU2
+24V
8, 15
2.5A
0V24
6
PSU3
-24V
1, 9
1A
0V24
13
Six 100nF 63V ceramic capacitors decouple the
DC outputs close to connector K30.
TECHNICAL OVERVIEW
Issue A May 1998
Synergy Mobile Workshop Manual
Chapter 4 Page 13
Isolated mains
outlets
PSU 2
Filters for isolated mains
L L L N N N
Fuses
Isolating
transformer
Termistors
Mains On/Off
and inlet
Mains selectors
PSU 1
PSU 3
DC outputs
K29
K25
K27
-24V
+24V
+12V
-12V
15way D
type socket
Terminal block
for isolated mains
Figure 4-9 Interal layout of the Isolation Transformer and Power Supply