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KSC-5 (REGULAR RATE CHARGER}
Specifications
Source voltage ..........
0000 ee eee 120V/60Hz (K,M2 type)
220V /50Hz (M type)
Charging current. .........0-00
00 ee Approx. 80mA (KNB-3)
Approx. 160mA (KNB-4)
Chargetime............
00002 eee
Approx. 15 hours (at 25°C)
Ambient temperature
Dimensions (Body only)
Weight
Circuit description
The
KSC-5
is a trickle charger fot the KNB-3A
and
KNB-4 Ni-Cd batteries.
Charging Circuit
When
a KNB-3A
is connected,
charging
current flows
through
Q1
: 2SB507E. The current flow to Q1 ts limited
*
to a value
determined
by the voltage
drop across
R3,
Zener diode DZ1, and the base-to-emitter voltage VBE of
Q1, given by the following formula:
1.3
|
— = 87mA
(Approx.
ie
mA
(Approx.)
The equations above indicate that the KNB-3A charges
at a Maximum
87mA.
As charging progresses, this value
becomes lower.
re
5°C~40°C (41°F ~104°F)
ees
7.87" (200mm) W x 5.28" (134mm) D x 3.35" (85mm) H
nn
ees
1.81 Ibs (820g) (K,M2 type)
1.9 Ibs (860g) (M type)
When
a KNB-4
is connected,
charging
current
flows
through
Q1
and
Q2
: 2SB507E.
The
maximum
current
through Q1 is 87mA
as above. The current through Q2 is
limited
in the
same
way
as
the
current
through
Q1,
resulting
in the
same
maximum
87mA.
The
KNB-4
is
charged
by the
sum
of the Q1
and
Q2 currents
(max-
imum
174mA).
As charging progresses, the value becomes
lower.
Indicator Circuit
The voltage drop across the emitter resistor R3 of Q1
turns
on
Q3
2SA608E,
supplying
current
to
the
CHARGING
indicator in LED1.
105
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