Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on March 24, 2018, 05:44:18 pm

Title: Redundant fuse - The better use ?
Post by: kagliostro on March 24, 2018, 05:44:18 pm

I'm placing on an amp an IEC inlet, in the same unit there is a line filter, an ON/OFF switch and two fuse holders

(https://i.imgur.com/fyDPEoy.jpg)

I'll use one of the fuses for the line and I'm wondering which will be the better use for the other fuse

the other wire of the line ? - B+ protection ? - Heaters ?

Please suggestions

Thanks

Franco

Title: Re: Redundant fuse - The better use ?
Post by: PRR on March 24, 2018, 08:11:58 pm

I'd keep the wall-power module ONLY wall-power stuff.

I don't like the idea of bringing "safer" wiring on the PT secondary back next to the wall-power.

Your regulations encourage double-pole switches. Double fuses on the wall-power may be a similar thought.

Title: Re: Redundant fuse - The better use ?
Post by: kagliostro on March 25, 2018, 01:43:06 am

I forgot to say it is a 3 W  amp and  B+ is near line voltage (260v)

However I'll follow your council, as you say the switch is  DPST

Thanks

Franco

Title: Re: Redundant fuse - The better use ?
Post by: trobbins on March 25, 2018, 01:38:46 pm

K, has that really got two fused connections!
Do you have a link to part spec?

Title: Re: Redundant fuse - The better use ?
Post by: kagliostro on March 25, 2018, 03:09:43 pm

Ciao Tim

https://docs-emea.rs-online.com/webdocs/140a/0900766b8140a4e0.pdf (https://docs-emea.rs-online.com/webdocs/140a/0900766b8140a4e0.pdf)

https://uk.rs-online.com/web/p/iec-filters/8826888/ (https://uk.rs-online.com/web/p/iec-filters/8826888/)

At a Ham Fest I got 2 (new) for 5 € I was surprised when I've seen the retail price is more than 20 € each  :huh:

I've been lucky

Franco

Title: Re: Redundant fuse - The better use ?
Post by: trobbins on March 25, 2018, 04:46:52 pm

Hmmm.  So G,H,J, K terminals in datasheet connect to the two fuse terminals?


Never come across that before  :w2:

Title: Re: Redundant fuse - The better use ?
Post by: kagliostro on March 25, 2018, 06:11:42 pm

Yes, tomorrow I'll post a pair of photo

(on 21-22 april there will be one other Electronic Fier with Radioamateur Flea Market, I think I'll see the guy from which I got the inlet and I'll get some others, if he has more)

Franco

Title: Re: Redundant fuse - The better use ?
Post by: kagliostro on March 26, 2018, 06:34:50 am

Here the photo

you can see the small door and inside two sledges where you place the fuses

(https://i.imgur.com/bhpVh26.jpg)

(https://i.imgur.com/pzPdXDL.jpg)

(https://i.imgur.com/QcKDvEA.jpg)

(https://i.imgur.com/4QwogAZ.jpg)

Franco