Erbe ICC 200, Service Manual

Page: 54 / 266

1 TEST PROGRAMS AND ADJUSTMENTS 54
/ 266
Adjustment 1
Power supply unit phase relationship
Procedure
• Unplug power cable from the ERBOTOM ICC.
• Pull off the black lines on the bridge-connected rectifier BR 1 on the motherboard and connect an
adjustable isolating transformer to BR 1 in its place, the output voltage of which is adjusted to 0 V.
With well prebalanced boards, a transformer with a fixed voltage of approx. 155 V AC can also be
used.
ATTENTION !
For units which are set to 120 V, you must absolutely make certain that the Erbotom ICC is operated via an
isolated transformer. In addition, the connection between J15 and J20 on the motherboard must be removed
from J15.
• Connect 200 ohms load resistance (e.g. APM 600) to MP1 = GND and MP2 on the power module
(slot J5).
• Connect the oscilloscope to MP1 = GND and MP2 = probe on QC power stage end stage (slot J4).
• Plug the power cable for the Erbotom ICC back in and activate Test program 16, Adjustment 1.
• Activate using the yellow pedal on the footswitch (AUTO CUT).
• Slowly increase the output voltage on the isolating transformer. With a correct setting, the voltage
characteristic corresponds to the graph illustrated below, whereby the small dip (approx. 20 V) next
to the square-wave edges represent a good criterion of evaluation for this.
• Set the phase angle using TP13 (control board, slot J3). For the final setting, the square-wave voltage
must be increased to approx. ±100 V. (Display in AUTO CUT approx. 205).
• After the setting is complete, disconnect the ERBOTOM ICC from the power, remove the cable from
the isolating transformer to BR1 and connect the two black lines again to the bridge-connected
rectifier.
Fig.: Voltage characteristic of supply unit power
T
1 >
1) Ch 1: 50 Volt 500 ns