ISO-500PP 420 watt power supply specs seem inadequate

[Bert van den Berg]

Hi all,

Recently purchased a ISO-500PP 420 watts power supply to modify for a high power battery charger project.

The ISO-500PP has the following rating printed on the case:

+3.3V 22.0A
+5V 36.0A
+12V 18.0 A
-12V 0.5A
-5V 0.5A
+5sb 2.0A

When I opened the unit to modify it to our requirements I was surprised to see that the rectifier for the +12V was a NXP BYO30E rated for only 16 Amps and that the 3V rectifier was a STPS2045 rated for only 20 amps. I could not see the numbers on the 5V rectifier but seems to me that if this unit is an indication, then this company is specifying it's power supplies above their actual ratings.

Regards,

Bert

 

[Michael Hawes]

Hi all,

Recently purchased a ISO-500PP 420 watts power supply to modify for a high
power battery charger >project.

The ISO-500PP has the following rating printed on the case:

+3.3V 22.0A
+5V 36.0A
+12V 18.0 A
-12V 0.5A
-5V 0.5A
+5sb 2.0A

When I opened the unit to modify it to our requirements I was surprised to
see that the rectifier for the >+12V was a NXP BYO30E rated for only 16
Amps and that the 3V rectifier was a STPS2045 rated for >only 20 amps. I
could not see the numbers on the 5V rectifier but seems to me that if this
unit is an >indication, then this company is specifying it's power supplies
above their actual ratings.

Regards,

Bert

You are correct. Custom PC in UK tested PSUs. Cheap PSUs were found to
struggle to acheive 75% of maximum rating for continuous operation.
Sometimes the ratings on the label are Peak, not continuous, which would
agree with what you have found.You will either need a cheap PSU with higher
rating, or a good quality(more expensive) 420W PSU.

Mike.

 

[larry moe 'n curly]

Recently purchased a ISO-500PP 420 watts power supply to
modify for a high power battery charger project.

The ISO-500PP has the following rating printed on the case:

+3.3V 22.0A
+5V 36.0A
+12V 18.0 A
-12V 0.5A
-5V 0.5A
+5sb 2.0A

When I opened the unit to modify it to our requirements I
was surprised to see that the rectifier for the +12V was a
NXP BYO30E rated for only 16 Amps and that the 3V rectifier
was a STPS2045 rated for only 20 amps. I could not see the
numbers on the 5V rectifier but seems to me that if this unit
is an indication, then this company is specifying it's power
supplies above their actual ratings.

Wow. Even the worst PSUs I've seen had components that were
adequately rated, including one with steel heatsinks. Is the power
transformer also small for a 500W PSU?