View Full Version : Power Supply bone head

02-09-2006, 05:07 PM

... times up .... nuke ......................................

02-09-2006, 05:23 PM
wow thats alot of mumbo jumbo to read :p:

02-09-2006, 05:45 PM
Nobody is safe when my clown hat is on.

not even Jon;

Originally Posted by JonMarsh
Many SMPS use NTC's for inrush current limiting, but then bypass them with a relay at the end of soft start.

This is getting WAY too close to my day job!


Seems like a retarded idea. NTC + Relay

He's one of the real engineers that you can rely on for good advice, not many of those in cyberspace.
He had his hand in the Crown K series amplifier design. That thermistor bypassed with relay thing
really doesn't make sense to me and my QSC amp has it too. Thermistors usually cost more too
and since manufacturers are always looking for the 'penny solution', you'd think they use the power
resistor method, the same method that is used and have been used for decades. Maybe is the new
'glam rock' engineering methods used today... Engineers with long hair akin to 80's metal music -> bad joke

02-09-2006, 09:06 PM
Digital Switching Power Supplies are more efficient because you don’t lose as much signal or gain distortion because of induction and capacitance in the huge windings of the transformers. This means that when the current need spikes the power supply can react faster, depending on the cyclic rate of the switching. Also, from experience with the CX1202 and other “70 Volt” Line amps, which usually need a lot of raw electrical power when running on bridged mono 140V driving line level equipment, the CX1202 with the Digital Switching Power Supply doesn’t “grunt” under a heavy load if the current levels are unavailable when the amp needs them. This efficiency with the power is great because believe it or not when you tell a promoter that you need 2x 120 Volt 50 Amp circuits you sometimes get an orange extension cord ran 50 ft from a source that’s hovering about 109 and only 20 amps (extreme situation that did happen, and with some foot to *** we did get decent enough power to work with aka a generator). But the same efficiency pays off in SQ and general reliability.

02-16-2006, 01:47 PM
I'm surprised those two guys are keeping the thread alive. Perhaps it's
my high charisma for black sheep ideas. :) :fart:


This is a classic example of why good companies have only one chief engineer
and the rest ordinary engineers -- too many cooks spoil the soup -- too many
chiefs and not enough indians ...

Imagine yourself owning a company and having too many 'think tanks',
you'd never have a product to sell because they'd never reach an agreement.

02-16-2006, 10:25 PM
I just raised the stakes, see that thread I linked.