Farnell G24-10A PSU - current-limit modification

[Edenyard]

I have an old Farnell G-series switched-mode PSU, type G24-10A (240
watt, 24V 10A) and it shuts down completely when the current drawn
from it reaches the limit threshold. The original spec sheet for the
PSU suggests that the normal behaviour is to enter a constant-current
mode when the current-limit is reached. I seem to remember that there
was a modification that could be done to these units to select whether
they shut down or gave constant-current but I can't find any reference
to this anywhere. I no longer have any instruction manual for the
unit, either.

Can anyone think back a few years to remember anything about this and,
more importantly, how to change the current-limit mode? Thanks!

 

[Jules]

... I seem to remember that there
was a modification that could be done to these units to select whether
they shut down or gave constant-current but I can't find any reference
to this anywhere. I no longer have any instruction manual for the
unit

If it's like the 120W units, there's an option to shut down after 200ms of
overload (option C). To disable this, fit a link across C5/R7 (22µ/56k on
the 120W) on the output board. Hope this applies to your unit.

 

[Edenyard]

If it's like the 120W units, there's an option to shut down after 200ms of
overload (option C). To disable this, fit a link across C5/R7 (22µ/56k on
the 120W) on the output board. Hope this applies to your unit.

Many thanks for that. The 240W unit doesn't have component references
C5 or R7 on the control PCB, but there's a 56K (R27) in parallel with
a 22u 16V tantalum (C12), so I tried linking across that and hey
presto! No more shutdown.

Thanks again,

Ed.