Regulated PS load step overshoot

classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view

Regulated PS load step overshoot

Hi all,

On Jan 21, Ted, KN1CBR posted regarding a suspected supply transient
problem damaging his K2.  This post encouraged me to check the response
of different power supplies to a load step from high to low load.  This
is a situation where the internal regulator in the supply can
potentially overshoot due to one or a combination of several factors:
poor regulator design, DC lead inductance, DC lead resistance and others.

The results of these load step tests are now posted on our site:
Select the 'Test Results' tab.

In general most name-brand supplies have minimal overshoot and decent
regulation, but some very inexpensive switching regulators have terrible
performance.  I would never suggest running expensive electronics on a
cheap unquantified switching power supply...or linear supply for that
matter.  A common failure mode for linear regulators when overloaded or
overheated is shorting of the pass device.  Without a crowbar circuit
installed this will of course put full unregulated voltage at the output
terminals.  Conversely, failure of a power device in a switching
regulator will cause the output to drop to zero.

Cheers & 73,

Howie - WA4PSC
Elecraft mailing list
Post: mailto:[hidden email]

This list hosted by:
Please help support this email list:
Message delivered to [hidden email]