Users Manual & Installation Guide
PV- 5127:
Power supply module with UPS
Page 12 of 31
System temperature
The PV-5127 has a temperature measuring circuit that can control an external fan and heater, and
prevent the CPU from starting if the temperature is too low or too high. It monitors the system
temperature as long as +5V STB is on.
As system temperature sensor, you can use the onboard sensor, or an external sensor of type
Infineon KTY 11-5 connected to J2 (labelled “Ext. sensor”). If you don’t want any temperature
control, you can also configure it to a simulated 10°C, which effectively disables the temperature
control.
The circuitry checks for four different temperature ranges:
too cold
,
cool
,
warm
, and
too hot
.
Range
Thresholds
Too cold
Below (0°C, 3°C)
Cool
Between (0°C, 3°C) and (15°C, 18°C)
Warm
Between (15°C, 18°C) and (47°C, 55°C)
Too hot
Above (47°C, 55°C)
There is hysteresis when moving between the ranges. The notion (0°C, 3°C) denotes the lower and
upper hysteresis levels, so that the change from
too cold
to
cool
happens when the temperature rises
above 3°C, but to change from
cool
to
too cold
, the temperature must fall below 0°C. Similarly for
the threshold between
cool
and
warm
(at 15°C and 18°C), and between
warm
and
too hot
(at 47°C
and 55°C).
For testing purposes, the
too cold
and
too hot
ranges can be simulated. To simulate
too cold
, mount
a jumper on J2 instead of a sensor. To simulate
too hot
, leave both J2 and ST3 unconnected.
The temperature ranges are used for these functions:
Range
CPU start
allowed
Heater
Fan
Critical alarm
Cold
LED
Hot
LED
Too cold
No
On
Off
No
Flashing
Off
Cool
Yes
Off
Off
No
Off
Off
Warm
Yes
Off
On
No
Off
Off
Too hot
No
Off
On
Yes
Off
Flashing
