Nano Power Inverter - Roll Your Own Style

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Joined: 21/06/2018
Location: Australia
Posts: 951
Posted: 06:15am 22 May 2019      

Ok now for some transformer discussion on my ebay purchase. The ad reads "5000W 240AC to 38V 80A toroidal transformer" 2 available. Here is a picture from the AD.

Other text from the ebay posting read:
Transformer removed from working device (LF 10000W off-grid inverter).
230VAC to 32VAC/80A
240VAC to 38VAC/80A
32VAC to 230VAC/16A
38VAC to 240VAC/16A

Size: D170 x H100 mm

Weight: 10 kG

I emailed him suggesting there is an issue with the text in the ads.
There are 2 wires for primary and 2 for secondary - no taps.
It cant be 230-32 & also 240 - 38, they are different ratios. I also pointed out that ot cant be 5kW and also 32V x 80A as that is only 2.56kW. Also 230 x 16A = 3.6kW.

The transformer finished dimensions are actually closer to OD 160mm, ID 55mm, H 90mm.
Weight is ~ 9.7kG

Compared to an Aerosharp I have is OD 195mm x ID 55mm x H 70mm. weight 11.2 kG.

I suggest that the sticker is either 5kW for both transformers or a peak value for 1 transformer it just doesnt feel like a 5kW toroidal. The cost was $180 for the 2 delivered.

I ask for comments, the transformers arrived yesterday I brought 2 hoping for the 10kW in the AD but I have a gut feel these are only good for 2 - 3 kW each. I will post the test data soon which is excellent. But do I complain about them or just let it slide and accept them for what they are ? I am disappointed but also know the value I paid is probably about right even if they are only good for say ~ 6kW in parallel ? Test data posted shortly.

Edited by wiseguy 2019-05-23
If at first you dont succeed, I suggest you avoid sky diving....
Cheers Mike