Standby switch Q

[tubenit]

Sluckey helped me on on the Carolina SuperSonic build in understanding the rectifier and the standby switch. It worked quite well!


So now I am on another build and it is requested that this build also have a standby switch.  Can I use type  "A" for the standby switch which is prior to the rectifier  OR should I be using type B after node A on the B+ rail?


With respect, Tubenit

[sluckey]

I would not use either A or B. Drawing A won't work as drawn. Point A should be moved to after the switch in drawing B. Make these simple changes and then use whichever one you want. I'd probably choose drawing A because AC current is easier on the switch contacts than DC current.

[tubenit]

Steve,  I am super grateful for your help!  I can't count how many times I was not understanding something or headed the wrong direction and you've generously gotten me back on course!  THANK you for taking the time to explain and even draw out the schematic!   I will follow your advice on this!


Most appreciative!  With respect, Tubenit

[pdf64]

FYI international electrical equipment standards mandate that the live feed from the wall outlet / IEC inlet should hit the fuse first, then the switch.
Ideally, live and neutral should be switched.
The live feed should go to the back terminal on the fuseholder, not the side one.

[tubenit]

FYI international electrical equipment standards mandate that the live feed from the wall outlet / IEC inlet should hit the fuse first, then the switch.

I did not know that? 

with respect, Tubenit

[PRR]

...international electrical equipment standards mandate ...

Tubenit isn't international, he's Carolina or thereabouts. 120V juice and single-pole switching.

I'd think if we are catering to dummies, the switch should be before the fuse, so the fuse holder may be made dead?

I'd ask for a cite of 'standards' but I know I could not afford to see them.

[pdf64]

My key concern was that the schematics showed a single pole switch on one side of the mains, a fuse on the other. It seems that if the mains connectors are polarised, it’s best to put the fuse and switch on the live side.
I think I should have left it at that
I’ll investigate the situation regards the standards.

[sluckey]

I’ll investigate the situation regards the standards.

Please report your findings.

[PRR]

> the schematics showed a single pole switch on one side of the mains, a fuse on the other.

That's remarkably standard for 1960s USA work. It does not need a wire-nut or other splice (or a DP switch, a many-penny extravagance in US commercial thinking).

An excuse is that it should be incredibly easy to Pull The Plug before putting a sweaty finger on a fuse. If we don't listen, our fault.

[pdf64]

Hasn’t North America changed to polarised mains connectors since then though?
That seems a different scenario to it being a coin flip which side is which, as with unpolarised connectors.

[PRR]

> changed to polarised mains

Only nominally.