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KSC-6 (COMPACT CHARGER)
Specifications
Source voltage .... 0... 0...
ee
120V/60Hz (K type)
220V/50,60Hz (M type)
120V/50,60Hz (M2 type)
0.79 Ibs (860g) : Charger
Design and specifications subject to change without notice.
Circuit description
The
KSC-6
is a compact
trickle charger for charging
KNB-3A and KNB-4 batteries.
' Charging Circuit
When a KNB-3A is connected, current flows through R8
(4782). The maximum charging current is approx. 160mA.
When a KNB-3A is connected, current flows through R8
(1002) and Q3 : 2SA1241Y. The current flow through
R6
to
the
battery
is maximum
approx.
100mA.
The
current
flow to Q3 is limited by the voltage drop across
R10, the forward voltage of diodes D4 and D5, and the
base-to-emitter
voltage
VVBE
of Q3, as given by the
following formula:
_ (Voltage across D4 and DO—VBE of Q3) _
R10
(1.2V-06V)_ 06
9
272
ra
mA
Approx.
Thus
current
flow to the KNB-4
in the completely
discharged
state
is approximately
320mA.
As charging
progresses,
the value
becomes
lower.
When
KNB-3A
or
KNB-4
is charged,
the current
limiting circuit, consisting
of Q2 : 2SA1241Y, D2 and D3 (output current approx.
160mA) is not working.
Indicator Circuit
The voltage drop across R2 and R3 turns on Q1 so
that
current
flows
to the red CHARGING
indicator
in
LED1.
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