inrush current - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 3rd September 2007, 08:22 PM   #21
aandy is offline aandy  United Kingdom
diyAudio Member
 
Join Date: Mar 2007
Location: in UK unfortunatly
the tools to make EI's are a tool for spinning a bobin eg motor lathe and a counter and you can do this by hand as well keeping count.
so any one can do the EI's
the toridal needs 30k usd off tools, magazens and tape heads, gear heads.
there is no cheap option.
andy
sed me your email
i can send you some pics
  Reply With Quote
Old 3rd September 2007, 08:26 PM   #22
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
I use big UI core, have you tried those, should work in a similar way like c-core, with seperate coils
  Reply With Quote
Old 3rd September 2007, 08:42 PM   #23
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Hi Andy,
Quote:
the carver amp uses a c core tx in near saturation mode,
Yes, this was the staple power supply for most of their amps. What ever he did, those "transformers" would draw excessive current with a sine wave input. We got many ordered by technicians that we wouldn't take back (after warning them first). I ran the Canadian factory warranty service center and parts depot.
Quote:
this is not a high frequency power supply,but uses a triac as a light dimmer!
True, I was including the PM 2.0 which is a switcher, around 2 KHz I think it was.
As far as the light dimmer is concerned - a gross simplification. The on time had to be carefully balanced. By the time the M1.0 came out he had that licked. Before that time, the triacs would fire inconsistently at no low. This produced a "ticking" sound.

The last design used a regular EI transformer that created high rails of 125 VDC each. This was reduced by a high frequency switching "down converter" that simply varied the duty cycle. Very nicely done too!

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 3rd September 2007, 08:51 PM   #24
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Hi Andy,
Quote:
i am working on hipower smps at the moment for my amplifiers.
Eva seems to be very well versed in these also. She certainly knows her stuff. This type of design makes far more sense at high power levels.

Quote:
the toridal needs 30k usd off tools, magazens and tape heads, gear heads.
I can understand that for sure. Even the winding for EI types should use more than a drill and counter.
Quote:
i have also managed a winding dept for EI txs 18years ago.
Now that is nifty! My interests and knowledge run more to analog circuits. You are way beyond my skill level here. I just sniff for that unmistakable burnt - sweet smell. You know the one.
Quote:
sed me your email
Sure, bhomester at gmail dot com. Thank you.
Quote:
it is quite likely you have had junk toridals, there are a lot about.
I am afraid that you are probably correct there. Manufactures of consumer gear normally do not use the best parts available. I would normally turn to Hammond or <forgot the other one> as they are both located in Ontario where I live. I actually did get to meet Fred Hammond before he died. He was a super guy, very helpful.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 3rd September 2007, 08:54 PM   #25
aandy is offline aandy  United Kingdom
diyAudio Member
 
Join Date: Mar 2007
Location: in UK unfortunatly
I am currently re doing my 3kw H class amp.
with smps would like to do down converter but time is to valuble to me.
have you worked on the crest amps?
andy
  Reply With Quote
Old 3rd September 2007, 08:57 PM   #26
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Hi Andy,
Quote:
have you worked on the crest amps?
Yes, but I sold my company about 10 years ago. So I haven't seen one for a long time now. I had more fun with lower powered good consumer amplifiers.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 3rd September 2007, 09:02 PM   #27
aandy is offline aandy  United Kingdom
diyAudio Member
 
Join Date: Mar 2007
Location: in UK unfortunatly
Have you heard of Bowers and Wilkins loud speakers and Aura where you are?
andy
  Reply With Quote
Old 3rd September 2007, 11:04 PM   #28
fotios is offline fotios  Greece
diyAudio Member
 
fotios's Avatar
 
Join Date: Feb 2007
Location: Δραμα - North Greece
Sorry for my intervention in this battle of Titans. In Greece there are 2 very serious workshops of transformer construction. The first be found in Thessalonika and made only EI transformers in verry high prices. The second be found in Athens and made only toroidal transformers in some lower prices. For toroidals i am a little reserved (because the solidity of their core depends on how much tight it is the winding of wires around the core and because the under layer of primary it is from thicker wire than the secondary then the strong tightening has some limit to not broken the primary wire) then i gave a special order as follows: 1) After the core formating and before the winding procces to dipped in enamel and left to dry. 2) During winding the wire dipped in enamel separatelly 3) Finally the whole construction fixed in a metal box with the use of epoxy resin. This extra work, it cost more 25euros per xformer. Finally when i deliver the xformer i left it in the shelf for 10 days to dry very well everything. Of course a such type xformer due to its metal case probably it has the most possible little electromagnetic radiation around it. Yet with so much care (i don't believe there is nothing furthermore of this) a verry little cracking of 50Hz heared from the core if you touch your ear on the case. Why this? Therefore it is worth the extra cost for a such type fortification of xformer?
I quote bellow a picture to view the construction

Click the image to open in full size.

Fotios
  Reply With Quote
Old 3rd September 2007, 11:29 PM   #29
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Hi Andy,
Quote:
Have you heard of Bowers and Wilkins loud speakers and Aura where you are?
Bowers and Wilkins yes, Aura no. Not unless the trade name is different here (eg. Crown and Amcron).

Hi Fotios,
Quote:
Sorry for my intervention in this battle of Titans.
No battle here. Also, you are not interrupting.

I am afraid we are straying from the main topic though. Comments on build quality of transformers are weakly on topic though.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 5th September 2007, 06:14 AM   #30
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
The classic soft-start power resistors in aluminium case bypassed by a relay can cause a lot of trouble when the relay fails to close. They don't go open until the temperature is enough to cook everything around them.

Also, in order to be reliable, the resistor and relay approach requires the amplifier circuit to be muted and put in standby mode (no bias) until the relay closes. Furthermore, the control circuit must ensure that the relay closes even in low line conditions.

An alternative approach is to place one or more low value power NTCs in series and bypass them with a relay. When placed in the primary side, this gets rid of both transformer flux imbalance inrush and capacitor bank inrush. I find this way more reliable, and it results in lower cost and a more compact layout.

In general, I find most people in this forum very reluctanct to any new ideas, circuits or working principles not matching the common practices of the past 30 years. The fact that a circuit hasn't been used for the past 30 years doesn't make it a bad circuit.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Using Inrush Current Limiters hollowman Power Supplies 6 16th June 2012 09:27 PM
5Z4 inrush current too high Craig405 Tubes / Valves 10 3rd September 2007 07:58 PM
inrush current Jules Tubes / Valves 8 26th December 2003 05:38 AM
inrush current limiters colden Parts 9 17th October 2003 09:43 PM
About Inrush Current JDeV Parts 0 2nd December 2002 06:40 AM


New To Site? Need Help?

All times are GMT. The time now is 06:06 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2