Which standard deals with SMPS output overvoltage?

[cupoftea]

Hi,
Googling this just reveals the standards for transient overvoltages.
Do you know which EN standard deals with the smps output overvoltages which happen when the feedback loop components go open circuit?
(pertaining to offline isolated SMPSs).

You would think output overvoltage detection would need
to result in latched shutdown, since if hiccupping, and on
no-load, then every hiccup_ON poors a bit more charge into the output
caps and they go higher and higher in voltage...as such danger ensues.

..so which standard tells that Latched shutdown is needed in case of feedback loop open circuit?...(which results
obviously in output overvoltage)

 

[Easy peasy]

The only standard I am aware of is an old telecom standard that required a latch off for Vout exceeding 65VDC for 100mS

 

[multipla]

Vout exceeding 65VDC for 100mS

what does overvoltage protection have to do with conductance?

 

[GreenTech0621]

Hi,
Googling this just reveals the standards for transient overvoltages.
Do you know which EN standard deals with the smps output overvoltages which happen when the feedback loop components go open circuit?
(pertaining to offline isolated SMPSs).

You would think output overvoltage detection would need
to result in latched shutdown, since if hiccupping, and on
no-load, then every hiccup_ON poors a bit more charge into the output
caps and they go higher and higher in voltage...as such danger ensues.

..so which standard tells that Latched shutdown is needed in case of feedback loop open circuit?...(which results
obviously in output overvoltage)

BS 7671 EN 60335 for SELV, foldback or Latch, hiccupping might increase the voltage spike specially if PSU is loaded.

 

[Easy peasy]

what does overvoltage protection have to do with conductance?

what does conductance have to do with this thread ?

--- Updated Sep 10, 2024 ---

It makes sense to stop your converter for excessive Vout - especially for charging Li-Fe-PO4 batteries - where overcharging can lead to fires.

We routinely put two OVLO ckts in our designs to avoid just this.

Just the other day there was a mobile home fire in the newspaper - traced to a faulty charger, charging a battery un-attended.

Most chargers should have a time-current monitor that stops them after a certain amount of A-hrs - it's just good commercial, and common, sense - as well as good basic engineering.

 

[multipla]

what does conductance have to do with this thread ?

I don't know, you mentioned it first, that's why I'm asking...

 

[KlausST]

Hi,

what does conductance have to do with this thread ?

The problem is caused in post#2

exceeding 65VDC for 100mS

mS --> milliSiemens = conductance
but it should be:
ms --> milliSeconds = time

Klaus