Adding a DMM (ammeter) to a variac

Jerry garrcia

Tele-Meister
Joined
Nov 14, 2021
Posts
442
Age
48
Location
Sweden
Hi. Have this variac and wonder if there is an easy way of connecting an DMM to the variac so I don’t have to build me a space consuming light bulb limiter. Living in an apartment with a family whom are tired of all my stuff. I have a cheap but accurate DMM an thought that there must be a way of integrate it ti the variac circuit for measuring how much amp is drawn.
Anybody has a suggestion? Preferably not to many parts and just some soldering and heat shrink if possible?
 

Timbresmith1

Friend of Leo's
Joined
Oct 1, 2010
Posts
3,449
Location
Central TX
The ammeter needs to be in series with the output to measure current (amps) and in parallel to measure voltage (measuring across the two output leads)
The one I have uses a switch to measure voltage or current- essentially switching between series and parallel.
Make sure the variac has a fuse for your protection.
 

Jerry garrcia

Tele-Meister
Joined
Nov 14, 2021
Posts
442
Age
48
Location
Sweden
this would be easy, and it is a good thing to have anyway:


So funny. Just found this one I was going to ask about. https://www.clasohlson.com/se/Elmätare-för-vägguttag/p/36-2897
Tried it and it’s almost exact. Unfortunately it’s in Swedish. Just 14.5$. Gonna try it in the variac once it’s time to power it up. Also just built a lightbulb limiter. https://www.instructables.com/DIm-Bulb-Tester-Current-Limiter/
Think I’m all set to soon power up the Charlie Cristian amp build. Since it’s a mirror build it’s been quite a hassle. My spatial thinking abilities is so and so.
0D943C64-71CE-4DD1-9C19-1FCE2A07E359.jpeg
 
Last edited:

LightningPhil

Tele-Holic
Joined
Dec 1, 2018
Posts
561
Location
Nottingham, UK
Current meter is a good idea. Built a couple of inexpensive volt meters into my one. Input and output voltages..

Any panel mount current meter would be good.
 




Top