SCHOEPS VMS 5 U - Manual (Page 7)

7
0.5 A fast-blow fuse will burn out. It is
accessible through the battery com-
partment; a spare fuse is provided
within the unit. The locations of both
the actual and the spare fuse are shown
in the drawing on the inside of the bat-
tery compartment lid. A pair of regular
pliers (not "needle-nose") can be used
to facilitate changing the fuse.
By maintaining separate grounds for
audio signals and for powering, the
supply regulation circuitry of the
VMS 5 U permits the sharing of a com-
mon power source with other equip-
ment, without the risk of ground loops.
Notes on operation with an AC
power supply
Any AC power supply that will deliver
at least 7 V at 500 mA in actual use
and an open-circuit voltage of no more
than 16 V will be suitable. For exam-
ple, the SCHOEPS AC power supply
VMS 5 DC (input = 230 VAC, equipped
with "Euro plug") delivers a stabilized
12 Volts DC.
Please note: Different countries use
different AC voltages. Always make
sure that your power supply is appro-
priate for the AC voltage where you are.
Notes on operation with exter-
nal batteries
The batteries should have a nominal
voltage of 6 to 12 Volts and a capacity
of at least 500 mAh. A 6-Volt set of
gelled lead-acid rechargeable batteries
Note the polarity of the DC power
connector: the positive pole of the
power supply must be connected to
the center contact of the external
powering socket (<18> on page 3).
The unit will not be harmed by reverse
polarity, but will not operate; a protec-
tive diode will prevent current from
flowing.
If a sufficient external DC voltage is
connected to the external powering
socket of the unit, the "EXT" LED (<13>
on page 3) will light, even if the unit is
turned off; it is strictly an indication of
available powering, not of the unit’s
on/off status. In this mode of opera-
tion, any batteries inside the unit will
neither be charged nor discharged.
If for any reason the external power-
ing should drop below the minimum
required voltage (e.g. loss or reduction
of AC power), the unit will immediately
switch over to battery power, assum-
ing of course that batteries of sufficient
voltage are in the unit; the yellow LED
will then go out. This automatic switch-
over will occur without any disturbance
in the audio signal.
The “LOW BAT” LED <13> will blink
when the input voltage is less than or
equal to about 7.5 Volts, but this can
be ignored unless the battery indicator
is at the low end of the red region.
The meter is calibrated with reference
to internal batteries and will “under-read”
slightly with external power sources.
If too high a voltage is applied to the
external powering socket, the internal