Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: rafe on October 20, 2019, 02:21:31 pm

Title: Flea Market Variac
Post by: rafe on October 20, 2019, 02:21:31 pm

I just picked this variac up {untested} (same model) It is missing the back panel cover with the fuse,socket and on off switch . However it is wired up . It has a three prong female and a two prong male.    female is hooked  to 2

and 3(no ground) male is hooked 2 to 4

. It has 1~5 available connections with 2 more unnumbered under them(Switch?)          It appears to be in good condition aside from the male cord having a lot of exposed copper along its length. I saw a thread on here about adding a meter on one. I paid $15 for it and I'd like to get it working safely if possible !Thanks in advance. 

 

Title: Re: Flea Market Variac
Post by: rafe on October 21, 2019, 12:17:40 pm

I don't think it is wired correctly from watching a couple of videos ,and the information on those was a little sketchy. I think the first one I watched was the correct wiring ,the second one started off with an 18v wallwart as a power source I think as long as I do that I can figure it out relatively painlessly.I am not sure about the switch or fuse.

This is the diagram on the variac I am going to try it with the same hook-up that is on it now. the two commons on #2 the black on 4 and the output on 3. I am thinking that the fuse and switch (10amp?) should go between the hot line and the variac .

Title: Re: Flea Market Variac
Post by: pompeiisneaks on October 21, 2019, 02:47:58 pm

I'd not plug it in until you can verify.  Get a few well lit high rez photos and post here so people can peek at it.

I probably am not the person to answer, just that there are others that will need to see what's wrong or right visually.

~Phil

Title: Re: Flea Market Variac
Post by: rafe on October 21, 2019, 04:30:44 pm

How is this ….camera is down . That is a drawing of  the hookup options on the variac and how it was wired(Picture would look the same but the details would not show)                I am thinking it is most likely correct. I will ground, fuse and switch it after I determine it functions .I will get to it later in the week if it works as it should I'll mount it to a bigger board and put a fuse,switch and outlet next to it and cover over the exposed terminals . I looked around to see if the part was available ,No luck with that!

Title: Re: Flea Market Variac
Post by: shooter on October 21, 2019, 06:03:22 pm

Quote

I will get to it later

you may not be here  :icon_biggrin:

ALWAYS assume a catastrophic fail for all unknown endeavors
at least plug into a sacrificial fused buss strip with switch
maybe look for a 6-12VAC wart n do math

Title: Re: Flea Market Variac
Post by: rafe on October 21, 2019, 08:04:12 pm

maybe look for a 6-12VAC wart n do math
Yup, that was the plan if it starts going too high on the meter I'll know . Hey I hope i'll be here; maybe I should  get a helper to do the actual test. Safety First.
"

the second one started off with an 18v wall wart as a power source I think as long as I do that I can figure it out relatively painlessly."