u2402b ETC-unknow, u2402b Datasheet - Page 10

• Manufacturer Part Number: u2402b
• Description: Fast Charge Controller Nicd/nimh Batteries
• Manufacturer: ETC-unknow

Current Regulation Via Phase Control (Figure 8)
Phase Control
An internal phase control monitors the angle of current
flow through the external thyristors as shown in figure 2.
The phase control block represents a ramp generator
synchronized by mains zero cross over and a comparator.
The comparator will isolate the trigger output, Pin 1, until
the end of the half wave (figure 8) when the ramp voltage,
V
mains half wave.
U2402B
10 (17)
ramp,
reaches the control voltage level, V
V
(Pin 18)
sync
Internal
zero pulse
Ramp
voltage
(Pin 17
)
100mV
Trigger
output
(Pin 1)
6V
0ms
f
mains
V ö
i
= 50 Hz
Current flow angle
Figure 8. Phase control function diagram
ö
10ms
i,
within a
V ö
i
Charge Current Regulation (Figure 2)
According to figure 2 the operational amplifier (OpAmp)
regulates the charge current, I
average value. The OpAmp detects the voltage drop
across the shunt resistor (R
value. The actual value will then be compared with an
internal reference value (rated value of 160 mV).
The regulator’s output signal, V
control signal of the phase control, V
adjusted state, the OpAmp regulates the current flow
angle through the phase control until the average value at
the shunt resistor reaches the rated value of 160 mV.
The corresponding evaluation of capacitor C
operational amplifier (regulator) output determines the
dynamic performance of current regulation.
20ms
V ö
i
TELEFUNKEN Semiconductors
sh
) at input Pin 6 as an actual
5,
ch
is at the same time the
30ms
Rev. A3, 14-Nov-96
(= 160 mV / R
ö
93 7697 e
i
(Pin 4). In the
R
at the
sh
),