I've been looking online for a 20amp variac and I see Amazon has them for about $100 and Ebay has them for about $70. They all look the same but I'm wondering if there is any real difference between them? They all list brand names that are odd like vevor and others. Any advice would be appreciated. Thanks.
Variac 20 amp advice?
Collapse
X
-
Re: Variac 20 amp advice?
No there is no real difference in the ones that have a red outer case
The voltage meters are crap but you can do a modification to it and have a very good setup the meter that fit it also needs a modification for it be very useful
If you buy one and you want to do a modification to meter just let me know and will find the post where I did the modification to it and what type of meter that will fit
When I have some money to spend I going to this same setup on a 5 amp version of to be able to power LED strips to figure out what voltage the strips are ( wish list )Last edited by sam_sam_sam; 06-16-2019, 03:48 PM. -
Re: Variac 20 amp advice?
Here is the post where I talk about how I figured out how and where you have to the modifications
https://www.badcaps.net/forum/showth...to+transformer
Here is where you can get this meter at
https://www.ebay.com/itm/Digital-AC1...gAAOxygo9Q5Xoj
If you decide to get this meter and have in front of you I show you which diode that you have to remove and add a 1N4007 diode and add a piece of wire and some hot glue to hold it in placeLast edited by sam_sam_sam; 06-16-2019, 07:01 PM.Comment
-
Re: Variac 20 amp advice?
I just bought the 5 amp version of it now because it getting harder to find this version when I look 6 months ago I found more Seller selling them now I see only handful of them selling them
So I will wait until until you have all the parts and we can do it at same timeComment
-
Comment
-
Re: Variac 20 amp advice?
I fitted mine with a self-powered digital AC voltmeter which starts to display at 60V and above - any AC product would typically not work at such a low voltage.My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.Comment
-
Re: Variac 20 amp advice?
When you do the modification that I am talking about you can read the voltage down 1.0 volts
The reason they can not read voltage down that low has do with the voltage divider to read voltage
You also have voltage reducer for the meter controller
In order for you to read voltage down that low you need to separate the meter power supply from the meter reading voltage divider circuit when you do this then the meter can read voltages that low
The meter that I have a link to can easily done you just have to —>
( remove one diode )
or
( cut the trace where this diode connects to the voltage input terminal block *** you have remove the top board of the meter controller in order to cut the trace you can also recap the board while you have it separated ***)
—> reroute the meter voltage divider circuit and hook it up to the outlet on the Variac
The meter power supply is hook to ON / OFF switch which now the meter is not powered by output of the Variac supply
One note
You do need to have a meter that can read its own power supply in order for this to work
Line / Netural you breaking the line side of the meter power supply / meter voltage divider circuitLast edited by sam_sam_sam; 06-20-2019, 08:49 PM.Comment
-
Re: Variac 20 amp advice?
Here is where I got the meter for the 5 amp version that I bought the one that I used in the 20 amp version would not fit in the same space
POWER GRID volt & amp monitoring GAUGE - Digital ampmeter / voltmeter combo 2in1
https://www.ebay.com/itm/POWER-GRID-...53.m2749.l2649
I will in next few days I show how I modified this meter module this was so easy to do
The modification to this board —> it shows where the 5 volt section for powering the meter so it can read down to ( [0] volts )
The modification is not finished and that is why I not showing it yetLast edited by sam_sam_sam; 07-01-2019, 06:58 PM.Comment
-
Re: Variac 20 amp advice?
$17 is fucking robbery.
i get them here:
https://www.aliexpress.com/item/32905549312.htmlComment
-
Re: Variac 20 amp advice?
I want to have this device working for a project that I want start working on
I am going to buy some of these meters that you gave me the link to next month
I have four orders from AliExpress that I am waiting for over three weeks for and still have not gotten here yetComment
-
Re: Variac 20 amp advice?
For my variac project, I took apart that mini voltmeter and brought out the Vsense wire, so it's three wires now. It's powered off the input mains but measures the variac output, so I can dial down to a few volts AC. No <60VAC dropout of the voltmeter.Comment
-
Re: Variac 20 amp advice?
Here is the modification on this meter module that I was talking about
In the photo I show where I cut the trace so it can measure down to ( 0 ) volts
I replaced the only capacitor that is in this unit
It had a 330uf@16 volt capacitor but the same valve capacitor was to fat to fit in there that I had on hand so I use a 220uf@16 volt capacitor instead and seems to work okay with itLast edited by sam_sam_sam; 07-07-2019, 11:36 AM.Comment
-
Re: Variac 20 amp advice?
One note about this modification is that you have to cut the trace on both sides of board in the same position which I forgot to mentionComment
-
Re: Variac 20 amp advice?
You are probably right about this however there is not really a lot of trace to work with if you are putting wires to the board
I did cut a deep slot in board on both sidesComment
-
Comment
-
Comment
-
Comment
Related Topics
Collapse
-
by Petr0xHi, I would like to share with you small modification to your Bosch tool 12V and 18V chargers.
You can use it for almost all Bosch chargers what I have seen, for example part numbers GAL 18V-20, GAL 18V-40, GAL 1880, GAL 18V-160, AL 1820, AL1115CV, AL1130CV.
Bosch (today also other brands using the same system like Wurth, Fein) does not care if you destroy your batteries, because they can sell you new ones. So the marketing is telling you only about speed of the charging, so you will not wait for your batteries to charge too long. Me as a customer want the tools and batteries...05-24-2024, 01:00 PM -
by tony359Hi all,
I have an old Apple II monitor to restore and I do have a big variac. I've always wondered whether a variac is a good idea to power on equipment which has been unpowered for (likely) decades?
When it comes to analogue stuff, I suppose it's ok and I'm probably going to see the device slowly coming back to life with a lower voltage applied.
But I suppose this won't work for devices with digital components in it as they won't work unless the proper voltages are applied?
In case of an old monitor, it is safe/good for the monitor to...10-13-2023, 02:47 AM -
by Green ProbeHi, Im looking to replace some EMP21N03 mosfets on an Alienware motherboard, but I'm having trouble finding a legit supplier. The ones that are available from China have pictures with the engraved logo looking very scratchy and sketchy. Nobody in the US sells them. I'm trying to find a compatible mosfet, but I'm not well versed enough to be confident im making the right choice. Does anyone have a suggestion or advice that could help me find the right mosfet? Thanks!
-
by user234Hi all,
Recently installed a new motherboard but during the process I seemed to have damaged my Gigabyte Eagle 3060 Ti card.
My motherboard ROG STRIX B550-A is detecting an issue with the VGA (light ON)
I have attached 2 photo's of my GPU board, one above and the other is what I believe to be the 5V - as you can see, this has visual damage so looks suspicious to me.
If I replace this part what are the odds this will resolve the issue? - any additional information on where to source the parts would be much apricated too!
This is...-
Channel: BIOS & Schematic Requests!
05-10-2025, 04:25 AM -
-
by artvandalaiI bought this Chinese made step up transformer to run some 220v appliances. Some of the wires were brittle and broke off. I attempted to improve some of the wiring with spade terminals and heatshrink tubing as the wires were just soldered straight to the connectors. Any advice on how to rewire the broken wires on this step up transformer? I'm unsure how to go about rewiring this to a better safe working condition.6 Photos
- Loading...
- No more items.
Comment