22
Internal temperature calculation example:
1. Hex readback: 68 (0110 1000).
2. Convert hex readback to decimal: 104
3. Calculate the measured temperature:
Temp=104*0.391=40.664oC
Fig 7-3: Typical application of I2C interface
7.5.3 Internal temperature measurement
The internal ambient temperature is measured to provide information of the safe operation of the power supply. The
internal ambient temperature is usually higher than the power supply air intake temperature due to internal power
dissipation. As the power dissipation varies with the load, the internal ambient temperature increases with the load.
Refer to Fig 7-2 for typical internal temperature rise above the air intake temperature versus the load.
Fig 7-2: Internal temperature rise vs. load
7.6 Typical application diagram
A typical application is described in Fig 7-3.
FPS1000
ON/OFF
CONTROL
LOAD
+
-
+V
+S
-S
-V
RS232 TO
I2C
CONVERTOR
PC
RS232
CABLE
ON/OFFSIGNAL
RETURN
SCL
SDA
A0 A1 A2
ADDRESS
SETTING
CLOCK
DATA
GND
RS232
Internal temp.
rise (°C)
15
10
5
0
25 50 75 100 % of rated load