Power supply
Strato Pi UPS can be powered with DC voltage only:
✓
DC: nominal voltage range 9.0V to 28.0V.
Respect the correct polarity shown in the schematic diagram (+ -). The power supply
circuit implements reverse polarity protection using an auto resetting fuse and surge
protection up to ±1000V/2ohms 1.2/50
μ
s.
A blue on-board LED, also visible through the front panel of the DIN-rail case, is lit when
power supply is available.
When a Strato Pi UPS board is used, never connect the Raspberry Pi micro-USB power
plug.
The Strato Pi UPS power supply stage is optimised to deliver up to 4A at 5V to the
Raspberry Pi. Because Strato Pi has a 2.2A resettable fuse (polyfuse) on the power supply
line, the maximum current that its regulator can deliver is also limited by this fuse, and
depends on the input voltage. The following table lists the typical measured output current
of the power supply stage at different input voltages and the corresponding input current.
STRATO PI UPS POWER SUPPLY STAGE TYPICAL IN/OUT VOLTAGE AND CURRENT
9V
12V
24V
Iout
Vout
Iin
Iin
Iin
0.1
5.09
0.13
0.10
0.08
1.0
5.05
0.71
0.52
0.28
1.3
5.04
0.91
0.67
0.35
1.5
5.03
1.05
0.76
0.39
1.8
5.01
1.27
0.91
0.46
2.0
5.00
1.42
1.01
0.51
2.5
4.98
1.80
1.27
0.64
2.7
4.97
1.94
1.38
0.68
2.8
4.96
FUSE
1.43
0.71
3.0
4.95
1.54
0.76
3.5
4.92
1.88
0.89
3.7
4.91
FUSE
0.94
4.0
4.90
1.02
4.2
4.88
1.08
4.3
4.85
1.10
4.4
REG
14
Strato Pi UPS User Guide
