First variac  - Page 1
Forum section: electronics / beginners

author: Arkie
author_rank: Newbie
timestamp: September 09, 2023, 10:43:08 am
content: Hello does anyone know from experience if the jaycar Variac is any good?

author: Synthtech
author_rank: Regular Contributor
timestamp: September 09, 2023, 11:14:07 am
content: I have one. It’s useable but the scale on the top of the device is useless across about a third of the travel, it’s like the windings are not at all linear so you have to rely on the little meter on the front or use a multimeter to verify the actual voltage output, At some places on the printed top scale it’s up to 15V out. The other thing that I noted when I looked inside is that the internal mains connections are soldered and it is amateur tack soldering that is at best sub-standard. I do get use from it but I always verify the output with a multimeter. If you purchase one I would also advise adding a 2A fuse to the wiper output to protect it from shorts or excessive current draw from the destination device.In short they are useable but not good quality.

author: David Aurora
author_rank: Frequent Contributor
timestamp: September 10, 2023, 01:29:11 am
content: Here's the skinny on any and all Jaycar test equipment:1. If it comes from Jaycar it's almost certainly going to be junk.2. It's going to be the exact same thing you can get off Aliexpress for 1/3 of the price if you can wait 3 weeks.3. Only ever buy test equipment from there if you accept rule #1 and you don't have time for rule #2I got one of these a while back because I was out on a job and suddenly needed one, and I didn't want to run back to the workshop and get my real one (it's huge and semi-inaccessible, it has a remote so I've got it tucked away to save space). It's been used a handful of times and so far hasn't exploded, so that's good. I haven't pulled it apart but I'd absolutely believe what Synthtech has said and follow their advice if you buy one. I've never assumed I could trust the meter on it anyway so haven't even looked at it when setting up.EDIT- correction, 1/5 of the price. And now with LCD readout, so expect a new improved model coming to Jaycar in 2029!https://www.aliexpress.com/item/1005005986109233.html?spm=a2g0o.productlist.main.13.8e0c48falX2SgC&algo_pvid=d3b70b65-f618-43a8-9b36-d0f8176315af&algo_exp_id=d3b70b65-f618-43a8-9b36-d0f8176315af-6&pdp_npi=4%40dis%21AUD%2179.46%2155.62%21%21%2150.00%21%21%40210318cb16943091683587783e82d8%2112000035187897166%21sea%21AU%210%21A&curPageLogUid=k2KTlGz0vFfl

author: WimWalther
author_rank: Regular Contributor
timestamp: September 10, 2023, 04:25:15 am
content: My advice is simple: Try to find a used USA made unit. Any size 3A or greater should be fine for most anything you're likely to do. Names like Staco, Superior Electric are top quality.Now here's something to think about: Why is it that a 12A Chinese variac weighs about the same as a 5-7A US‐made unit.. when capacity comes down to hard rules of core mass and wire diameter?

author: Ian.M
author_rank: Super Contributor
timestamp: September 10, 2023, 05:30:22 am
content: Unfortunately, many US Variacs are 120V input, so are useless to most of the rest of the world. There's also the 60 Hz vs 50 Hz issue - at the lower frequency, a 60 Hz Variac that isn't dual rated will need its input voltage derated 20% to have the same margin below saturation. Variacs are also heavy and prone to damage if poorly packed, so importing a used one could be an expensive gamble if not dealing with a specialist seller.You should readhttps://www.eevblog.com/forum/beginners/shopping-for-a-variac-shopping/'tkamiya's posts there, detailing the teardown and testing of a cheap Chinese import variac are particularly noteworthy.

author: Shock
author_rank: Super Contributor
timestamp: September 10, 2023, 09:38:05 am
content: I brought a Superior Electric Powerstat 236B which is suitable for both AU and US usage, it's 240V 10A 50/60Hz with a 0-280V scale. Perhaps an overkill but I didn't want to buy twice. Quite costly new but secondhand, shipped to AU they are affordable.You can read further posts and my comments in the thread linked below. Note there was a few unhinged posts by engrguy42.https://www.eevblog.com/forum/beginners/shopping-for-a-variac-shopping/msg3065186/#msg3065186