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.

Internal temp. rise (°C)

15

10

5

0

25

50

75

100 % of rated load

Fig 7-2: Internal temperature rise vs. load

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

7.6 Typical application diagram

A typical application is described in Fig 7-3.

PC

RS232

RS232

CABLE

RS232 TO

I2C

CONVERTOR

 

 

 

ON/OFF

 

 

 

 

CONTROL

CLOCK

SIGNAL

ON/OFF

+S

RETURN

 

 

+V

SCL

 

 

 

DATA

FPS1000

 

SDA

 

 

 

 

 

 

 

 

-V

GND

A0

A1

A2

-S

 

 

 

 

 

 

 

ADDRESS

 

 

 

 

SETTING

+

LOAD

-

Fig 7-3: Typical application of I2C interface

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TOA Electronics FPS1000-12, FPS1000-24, FPS1000-32, FPS-S1U, FPS-T1U, FPS1000-48 instruction manual Typical application diagram