HSF (M) 600W 042315
9
3.3
KEYING
Keying of the HSF 600W is established at the factory. The output voltage determines which key
pins are installed (see Figure 3, Detail A). When the proper holes in the rack adapter are blocked
by keying screws installed by the user, only a power supply of the correct voltage can be inserted
in the rack adapter slot. Refer to the RA 19-4C Manual for rack adapter keying instructions.
3.4
OUTPUT VOLTAGE CONTROL
Output Voltage can be controlled from either the front panel (PAR. 3.4.1) or externally using a
trimpot or voltage source (PAR. 3.4.2).
3.4.1 FRONT PANEL VOLTAGE CONTROL
Output voltage can be manually adjusted with the voltage adjustment control, Vadj (see Figure 5
for location) when DIP switches SW1 and SW2 (see Figure 4 for location) are configured as
shown in Figure 6A (factory default) To adjust voltage, first place the unit under an operating load.
Then monitor the (+) and (–) test points on the front panel with a precision voltmeter and turn the
voltage control to the desired operating value. Refer to Table 2 for the recommended Output
Adjustment Range of all HSF 600W M and MZ Models.
3.4.2 REMOTE VOLTAGE CONTROL
For remote voltage control, set positions 1, 2 and 7 for SW1 and SW2 as shown in Figure 6B. This
removes control from the front panel Vadj control and allows the output voltage to be adjusted by
either an external trimmer pot (resistance) or by an external variable voltage source connected
across the rack adapter I/O connector pin 12 (RV, Remote Voltage) and pin 10 (–COM, Common)
as shown in Figure 7. At the rack adapter I/O connector use a shielded wire 6.6 feet (2M) maxi-
mum in length, for connection of REF (pin 2), RV (pin 12), and –COM (pin 10) to the trimmer con-
trol or external voltage source.
NOTE:If remote voltage control is not implemented, the factory default for positions 1, 2 and 7 of DIP
switches SW1 and SW2 must be restored (Figure 6A).
FIGURE 6. DIP SWITCH SETTINGS FOR CONTROL OF OUTPUT VOLTAGE
It is possible that overvoltage protection may be triggered if the output voltage is decreased to a low
level very quickly when the power supply is at a low load condition.
3043281
COM 7
REF 1
RV 2
1 REF
2 RV
ON
ON
USING Vadj CONTROL
FRONT PANEL VOLTAGE CONTROL
A
B
(FACTORY DEFAULT)
REMOTE VOLTAGE CONTROL
OR VOLTAGE SOURCE
USING EXTERNAL TRIMPOT
COM 7
REF 1
RV 2
2 RV
1 REF
SW2
SW1
7
7
TAB
OFF
OFF
1
1
2
2
ON
SW2
SW1
7
7
OFF
1
2
ON
1
2
OFF
