Author Topic: Good Quality Variac with Isollation  (Read 1469 times)

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Offline 2XTopic starter

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Good Quality Variac with Isollation
« on: October 14, 2023, 08:43:42 pm »
Hello,
do you know any good brand of Variac with isolation between input and output voltage? The only I found is a red one from China and I am not sure that it has isolation.

Also I found this which is a complete power supply:
https://www.peaktech.de/uk/PeakTech-P-2235-Control-isolating-transformer-1000-W-0-30-V-5-A/P-2235

MA 4804 Power supply (I asked for this in a local store and told me that is no longer in production)
https://metrel.co.za/shop/equipment-for-laboratories-and-schools/ma-4804-power-supply/

 

Online ddrl46

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Re: Good Quality Variac with Isollation
« Reply #1 on: October 14, 2023, 08:56:21 pm »
I've had good experiences with the EA-STT 2000B-4.5 from Elektro-Automatik:
https://elektroautomatik.com/shop/en/products/industrial-power-supplies/ac-sources/power-supplies-variable-and-isolating-transformer-ac-dc/232/transformer-0..260v/4.5

This unit is fully isolated, slight downside is the slow update rate on the display. This can however be improved somewhat with a slight modification.
 
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Offline johansen

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Re: Good Quality Variac with Isollation
« Reply #2 on: October 14, 2023, 10:54:50 pm »
I cant say this for certain but i have no memory of ever seeing an isolated variac, that is, a variac winding over the top of the primary coil, which is a shame because traditional variac transformers are rather inefficient by weight, due to the difficulty of getting a high copper density. It would be rather easy to fit a primary coil under the secondary variac, if the inner diameter of the core were increased a bit so that the secondary coil is a standard 2:1 inner to outer ratio suitable for machine winding a variac

I had a burned up 0-260vac 10 amp rated variac, i rewound it with 15 gauge wire and i think i can get 140vac out of it at 4 watts of no load losses.

I think the original 260vac winding was 20 gauge wire, but it might have been 18.

 
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Offline johansen

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