New Module by Lars Clausen

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#141
Lars,

Do your modules/PSU allow for momentary push button type switches? ie. a latched relay type operation or similar?

Here's the switch I'll be using:
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=4303076&N=0

And the datasheet:
http://www.farnell.com/datasheets/36350.pdf

I believe Hypex has a softstart module that allows the use of one of these push buttons:

http://www.hypex.nl/docs/softstart.pdf

Also do you have a delay to avoid turn on/off thumps? I plan on running active so the last thing I want is a nasty turn on transient making its way to a tweeter.

Thanks
Ant
 
#142
ShinOBIWAN: I am sorry, at this point i don't have a soft start circuit in my programme, so nowhere to connect the pushbutton.

But the modules will accept a soft start circuit with no problems.

There are no start / stop bumps from the amplifiers, only a very small 'click' when the microprocessor turns the amplifier on.
 
#146
I have already made it a note in my calendar, AND my task board, where it will not disappear from, until i manually delete it. 😀

Just tonight i have been working through the protection system, and made very hard stress tests to a module. And i must say the 'full software control' has proven very helpful, and even more worthy than i had expected. Anyway it's incredible how much abuse the modules will take, i tested repeated peak currents of about 150 Ampere, every 3 seconds for half an hour.
Even at artificially elevated temperature of 90 deg. C on the output stage, it survived the stress test without a glitch.
(The module got 90 deg hot producing 100 Watts in 4 Ohms for about 20 minutes, without any heat sink connected to it). (Not recommended operation condition!)

During the whole stress test so far, i didn't burn out a module even one single time. (Pure Luck! 😀)
 
#152
I like the softstart, just to control the in-rush to the power supply.
Keeps the power supply from drawing large amounts of current just to charge the caps.

Maybe for home use this isn't that important, but for portable field use it can be a problem.
 
#154
Hi Gary

The modules have to comply with CE regulations for RF emission, (EN-61000 limits) meaning almost no emission is allowed between 1.5MHz and 1GHz (airborn with wires connected) and 0.15 - 15MHz wire carried. So if you follow the instruction provided with the modules, you shouldn't worry about any disturbances.

Furthermore it's a big day today, 🙂 the first module passed all 21 points in the safety test, without a glitch. And through the entire safety test work, though stressed out and abused, :smash: no modules were injured or damaged. 😎 It's stable...

You can see the safety test [Here]
 
#156
Lars Clausen said:

Furthermore it's a big day today, 🙂 the first module passed all 21 points in the safety test, without a glitch.
Click to expand...

Congratulations!! That is very impressive, and good news indeed.

If I can find a way to deal with the low input impedance, I'm just going to have to jump in and give these a try.

Thanks,
Gary Dahl
 
#157
Anzgar said:
I don't think it's important to include a soft start in an amplifier that draws nearly zero current in the start moment.In a class A amp that has an initial current of several amps it's otoh definitely valuable.
Click to expand...


Seriously, look around the forum, it's been debated to death, there's a need for them, especially with larger toroidal transformers, plitron would recommend one at anything above 300VA.
 
#159
Yes, very much!

The inrush problem stems from toroidal construction with its severe limits on magnetic flux density at saturation, in other words a brick wall and no more magnetic energy can be stored. Inductance drops drastically at saturation leaving only the very low primary DC resistance to limit current. Actually this is not true as house wiring and such does pose limits. I don't know about you but I would feel better not having my house wiring be what sets this limit!
With high power toroids there is another problem relating to residual magnetism being left in the core. This can cause very high inrush currents even with no load. I see and hear it with my variac all the time.
Roger
 
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