Fuses...what's the deal?

evanc · 23rd January 2011, 12:47 AM

So I'm putting my preamp into its chasis today and I get to the fuse holders for the wall current. I'm hooking up 12ga from the wall and fairly large wire to the transformer and than there are the fuses. I installed 2amp glass tube fuses. the wire in it is tiny......Is this something that is considered? Is there a certain type that is better than another?

mashaffer · 23rd January 2011, 01:16 AM

It has to be that way to work. The total resistance of a wire is a function of diameter and length anyway. A 1/4" length doesn't have to be nearly as big as a 25' length. Don't worry about it.

boywonder · 23rd January 2011, 02:19 AM

Quote:

Originally Posted by evanc

Is there a certain type that is better than another?

Slo-blo fuses will survive high in-rush currents where fast blow types of the same current rating will pop. If you have lots of power supply capacitance, you can have high in-rush current.

Ty_Bower · 23rd January 2011, 02:34 AM

?

aardvarkash10 · 23rd January 2011, 02:41 AM

tomchr · 23rd January 2011, 05:10 AM

Take the VA rating and divide it by your nominal mains voltage. Multiply by 1.33. That's your fuse rating. Use a slow-blow fuse. If the fuse still blows on turn-on, install a soft-start circuit.

So for, say a 200 VA transformer running on a 120 V system, the appropriate fuse would be: (200/120)*1.33 = 2.22 A. So use a 2 A or 2.5 A fuse (standard values).

~Tom

evanc · 23rd January 2011, 12:21 PM

Thanks for the replies. I use a soft start...no blown fuses. I was more thinking about the bottleneck of the tiny wire in the fuse. Slo-blo fuses look to have a longer length of tiny wire coiled up in them. Thanks again...Evan

DF96 · 23rd January 2011, 02:42 PM

The electrons might slow down at the bottleneck, but they will cope. Electrons are very flexible like that.

mastodon · 23rd January 2011, 02:48 PM

For a moment, I thought this thread was going to be about which type of fuse makes for the best sound.

CopperTop · 23rd January 2011, 02:54 PM

Quote:

Originally Posted by mastodon

For a moment, I thought this thread was going to be about which type of fuse makes for the best sound.

It is, isn't it? The suggestion is that you use massive solid platinum cable to wire up your amp to the mains, then pass the current through a filament as thick as a human hair. Why use the massive mains cable at all?

23rd January 2011, 12:47 AM	#1
evanc diyAudio Member Join Date: Sep 2009 Location: New Jersey. About 1 hour from NYC and 1 min. from the beach	Fuses...what's the deal? So I'm putting my preamp into its chasis today and I get to the fuse holders for the wall current. I'm hooking up 12ga from the wall and fairly large wire to the transformer and than there are the fuses. I installed 2amp glass tube fuses. the wire in it is tiny......Is this something that is considered? Is there a certain type that is better than another?

23rd January 2011, 01:16 AM	#2
mashaffer diyAudio Member Join Date: Jun 2004 Location: Indiana	It has to be that way to work. The total resistance of a wire is a function of diameter and length anyway. A 1/4" length doesn't have to be nearly as big as a 25' length. Don't worry about it. __________________ mike - www.keepingsundayspecial.org

23rd January 2011, 02:41 AM	#5
aardvarkash10 diyAudio Member Join Date: Mar 2007 Location: Auckland, NZ	__________________ Yes, conservatism thrives on low intelligence and poor information. But the liberals in politics... continue to back off, yielding to the supremacy of the stupid. It's turkeys all the way down. - George Monbiot, guardian.co.uk, 6 Feb 2012

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
looks like a deal to me	ZippyTs	Car Audio	6	8th February 2010 07:55 PM
What a Deal!	jkeny	Tubes / Valves	3	25th March 2009 09:36 PM

23rd January 2011, 02:34 AM	#4
Ty_Bower diyAudio Member Join Date: Mar 2007 Location: Newark, DE	?

23rd January 2011, 05:10 AM	#6
tomchr diyAudio Member Join Date: Feb 2009 Location: Greater Seattle Area	Take the VA rating and divide it by your nominal mains voltage. Multiply by 1.33. That's your fuse rating. Use a slow-blow fuse. If the fuse still blows on turn-on, install a soft-start circuit. So for, say a 200 VA transformer running on a 120 V system, the appropriate fuse would be: (200/120)*1.33 = 2.22 A. So use a 2 A or 2.5 A fuse (standard values). ~Tom

23rd January 2011, 12:21 PM	#7
evanc diyAudio Member Join Date: Sep 2009 Location: New Jersey. About 1 hour from NYC and 1 min. from the beach	Thanks for the replies. I use a soft start...no blown fuses. I was more thinking about the bottleneck of the tiny wire in the fuse. Slo-blo fuses look to have a longer length of tiny wire coiled up in them. Thanks again...Evan

23rd January 2011, 02:42 PM	#8
DF96 diyAudio Member Join Date: May 2007	The electrons might slow down at the bottleneck, but they will cope. Electrons are very flexible like that.

23rd January 2011, 02:48 PM	#9
mastodon diyAudio Member Join Date: Jan 2011	For a moment, I thought this thread was going to be about which type of fuse makes for the best sound.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read