6
not, the batteries need to be changed,
or recharged if they are NiCd/NiMH
types. When running on internal bat-
teries, the borderline between the red
and green zones is at about 7 Volts; at
this level the “LOW BAT” LED begins to
flash. With high-capacity rechargeable
batteries (1300 mAh) there should be
approximately a 10-minute interval
before the unit shuts itself off automat-
ically.
External powering
When the unit is externally powered
(and only then!) it is acceptable if the
battery indicator <12> is in the red
zone. It is calibrated for internal battery
powering, and its reading will be offset
slightly when external powering is used:
the boundary between red and green
will be at 7.5 Volts while the far end
of the green region will be at 10 Volts.
When the indicator is near the left end
of the red region the unit will no longer
function.
The “LOW BAT” LED <13> will begin
to blink at around 7,5 Volts, but can
be ignored with external powering.
3. Automatic shutoff
The unit will turn itself off if the volt-
age of the internal batteries falls beneath
the limit of proper functioning. This
avoids overly deep discharge of the
batteries, which could otherwise lead
to chemical leakage or, in the case of
rechargeable batteries, life-shortening
damage and possible cell reversal.
To turn the unit back on after an
automatic shutoff, turn the power
switch off and then on again, and/or
replace the batteries as needed.
When the unit is powered externally,
the automatic shutoff circuit is dis-
abled so that a brief interruption in
external power will not cause a pro-
longed shutdown in the absence of
internal batteries. However, a minimum
of 5.2 Volts (externally) must be sup-
plied for the unit to continue operating.
4. External powering
The VMS 5 U can be powered by
external batteries or AC power adap -
ters through a socket on the back of
the unit. The 5.5 mm/2.1 mm coaxial
power plug is a commonly available
part, and is found on AC power adap -
ters of many kinds.
We generally recommend using the
SCHOEPS mains adapter VMS 5 DC. If
another type or external batteries are
used, please note the following hints:
The voltage at the socket may be
anywhere between 5.5 and 15.5 Volts
DC.
Recommendation: voltage and current
(approximate):
6 V, 500 mA
8 V, 400 mA
9 V, 350 mA
10 V, 300 mA
12 V, 300 mA
15 V, 250 mA
Summary of Contents for VMS 5 U
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