Trying To Understand This Transformer Schematic/Diagram - I Want To Convert 120VAC to 24VAC, or 240VAC to 24VAC

Thread Starter

Mahonroy

Joined Oct 21, 2014
396
Hello, I am interested in using this transformer in a project:

https://www.mouser.com/ProductDetail/Wurth-Elektronik/750811248?qs=J4sk5G6CMwZ3EkszqNp3lw==
https://www.mouser.com/datasheet/2/445/750811248-1724441.pdf

Here is the schematic:
1651099009775.png

I am a bit confused how to wire this for 120VAC to 24VAC. It seems like I would run 120VAC hot to pin 1, 120VAC neutral to pin 4, and then connect pin 2 and 3 together. And then on the other side, I'm not sure how to handle pins 8, 9, 10, and 11 to get the 24VAC+ and common. Would I tie 10 and 11 together for the 24VAC+, and then 8 and 9 together for the 24VAC- (common)?

And then what if I want to configure this for 240VAC to 24VAC?

Thanks and any help or advice is greatly appreciated!
 

dendad

Joined Feb 20, 2016
4,134
60-400kHz????
That looks to be very odd specs for a transformer.
If it is just a 60Hz one, for 120V, pins 1 and 2 together to Active, pins 3 and 4 to Neutral.
For 240V, Active to pin 1, connect 2 and 3 together, Neutral to pin 4.
At lest that is what I would try.
 
Last edited:

Externet

Joined Nov 29, 2005
1,846
Seems like pins 1 and 2 tied together to 120VAC phase and pins 3 and 4 tied together to 120VAC neutral yields 24 VAC output between pins 5 and 6 or between pins 8 and 10. Find the specifications or its data sheet for extra details as pins 9 and 11.

For 240VAC input; phase to pin 1 and neutral to pin 4; with pins 2 and 3 tied together. Outputs same as above.
 

ronsimpson

Joined Oct 7, 2019
2,058
Short 2-3, 10-11, 8-9
Primary (4 turns) 1-4, power secondary 9,8 --10,11, Aux power 5-6. all (1 turn)
Nor really 4:1 turns but that is the turn ratio.
For switching power supply. Not for 60hz.
1651101535280.png
I will try to find a circuit to drive the transformer is you are interested.
ronsimpson
 

Dodgydave

Joined Jun 22, 2012
10,301
Hello, I am interested in using this transformer in a project:

https://www.mouser.com/ProductDetail/Wurth-Elektronik/750811248?qs=J4sk5G6CMwZ3EkszqNp3lw==
https://www.mouser.com/datasheet/2/445/750811248-1724441.pdf

Here is the schematic:
View attachment 265972

I am a bit confused how to wire this for 120VAC to 24VAC. It seems like I would run 120VAC hot to pin 1, 120VAC neutral to pin 4, and then connect pin 2 and 3 together. And then on the other side, I'm not sure how to handle pins 8, 9, 10, and 11 to get the 24VAC+ and common. Would I tie 10 and 11 together for the 24VAC+, and then 8 and 9 together for the 24VAC- (common)?

And then what if I want to configure this for 240VAC to 24VAC?

Thanks and any help or advice is greatly appreciated!
Are you wanting to make a switchmode psu to give you 24V from mains power,? if so please note that these are designed for high frequency use in a switchmode psu not for direct connection with 50/60Hz .
 

Thread Starter

Mahonroy

Joined Oct 21, 2014
396
Thanks for all of the responses! Yeah I didn't realize the application was for 60Khz on up... I thought it was 60Hz. So I'm guessing this transformer is not going to work for me?
 

meowsoft

Joined Feb 27, 2021
549
Thanks for all of the responses! Yeah I didn't realize the application was for 60Khz on up... I thought it was 60Hz. So I'm guessing this transformer is not going to work for me?
I can't work and can blow up like a bomb if you use with 60Hz
Don't do it, very dangerous
 

MisterBill2

Joined Jan 23, 2018
11,876
60Hz to 400kHz - almost four decades of bandwidth - now that would be impressive for a transformer!
No, it is 60 Kilohertz to 400 Kilohertz. The description is rather misleading. It is an inverter transformer. Then read the resistances on the data sheet. Also note that the transformer mounts to a circuit board, while the picture of the one in post #10 looks totally different.
 

Ian0

Joined Aug 7, 2020
5,082
No, it is 60 Kilohertz to 400 Kilohertz. The description is rather misleading. It is an inverter transformer. Then read the resistances on the data sheet. Also note that the transformer mounts to a circuit board, while the picture of the one in post #10 looks totally different.
It was irony (and coppery, too)
I’d say it was a flyback transformer.
something like this
https://www.onsemi.com/pdf/datasheet/fsl156mrin-d.pdf
would control it.
 

ronsimpson

Joined Oct 7, 2019
2,058
The transformer in question is much smaller than the one in #10. The picture in the Mouser catalog is slightly wrong. This one is from Digikey. 1.2 inch 32cm Note, low frequency transformers often have a core made from layers of metal. This high frequency transformer has a ferrite core.
1651236333417.png
 
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