Cosel CHS200, Инструкция по эксплуатации

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Voltage bVOUT and -VOUT should remain within the
output voltage adjustment range.
¡
If the sensing patterns are short, heavy-current is drawn and the
pattern may be damaged.
The pattern disconnection can be prevented by installing the pro-
tection parts as close as possible to a load.
¡
Output voltage might become unstable because of impedance of
wiring and load condition when length of wire exceeds 40cm.
4.6 Adjustable voltage range
(1) To adjust output voltage
¡
Output voltage is adjustable by the external potentiometer.
¡
When the output voltage adjustment is used, note that the over
voltage protection circuit operates when the output voltage is set
too high.
¡
If the output voltage drops under the output voltage adjustment
range, the Low voltage protection operates.
¡
By connecting the external potentiometer (VR1) and resistors (R1,
R2), output voltage becomes adjustable, as shown in Fig.4.4.
Recommended external parts are shown in Table 4.2.
¡
The wiring to the potentiometer should be as short as possible.
The temperature coefficient could become worse, depending on
the type of a resistor and potentiometer. Following parts are rec-
ommended for the power supply.
Resistor............. Metal film type, coefficient of less than ±100ppm/
C
Potentiometer.... Cermet type, coefficient of less than ±300ppm/
C
¡
When the output voltage adjustment is not used, open the TRM
pin respectively.
¡
The change speed of the TRM voltage should be less than 0.15V/
ms, when changing output voltage to less than 90% of the rated.
VR1
5k
W
+
+S
+VOUT
TRM
-S
-VOUT
1.225V
R1
RA
5.11k
W
RC
5.11k
W
R2
Control Amp.
of rated
voltage
Fig.4.4 Output voltage control circuit
Table 4.2 Recommended value of external potentiometer & resistor
No. VOUT
Output adjustable range
VOUT ±5% VOUT ±10%
R1 R2 VR1 R1 R2 VR1
1 3.3V 2.2k
W
68k
W
5k
W
2.2k
W
33k
W
5k
W
2 5V 4.7k
W
68k
W
5.6k
W
33k
W
3 10V 15k
W
68k
W
15k
W
33k
W
4 12V 18k
W
68k
W
18k
W
33k
W
5 15V 22k
W
68k
W
22k
W
33k
W
(2) To decrease output voltage
¡
By connecting the external resistor (RD), output voltage becomes
adjustable to decrease.
The external resistor (RD) is calculated by the following equation.
RD= -10.22 [k
W
]
Δ=
V
OR
-V
OD
V
OR
5.11
Δ
V
OR
: Rated output voltage [V]
V
OD
: Output voltage needed to set up [V]
RD
+VOUT
-VOUT
+S
-S
TRM
Fig.4.5 Connection to decrease output voltage
(3) To increase output voltage
¡
By connecting the external resistor (RU), output voltage becomes
adjustable to increase.
The external resistor (RU) is calculated by the following equation.
Δ=
V
OU
-V
OR
V
OR
RU= - - 10.22 [k
W
]
5.11
X
V
OR
X
(1+Δ)
1.225
X
Δ
5.11
Δ
V
OR
: Rated output voltage [V]
V
OU
: Output voltage needed to set up [V]
+S
-S
TRM
RU
+VOUT
-VOUT
Fig.4.6 Connection to increase output voltage
CHS-25
DC-DC Converters Bus Converter.Power Module Type
Instruction Manual