Help to identify this transformer (Algemeen)
door edison 
, Aveiro - PORTUGAL, 30.03.2020, 20:00 (1699 dagen geleden)
Hi.
I need help to identify this transformer. I think is a output transformer.
Please see the pictures.
![[image]](images/uploaded/202003301756585e8232ea7d52e.jpg)
![[image]](images/uploaded/202003301757425e823316beb08.jpg)
Many thanks.
Vriendelijke groeten,
Carlos
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From PORTUGAL, with regards
Carlos
Help to identify this transformer
door soundman2 , Wouw, 30.03.2020, 20:18 (1699 dagen geleden) @ edison
Seems to be an impedance transformator, used e.g. in 100 or 70 volt loudspeaker distribution systems.
Today power selection is choosen at the primary side with only a few speaker impedances at secondary e.g. 4 and 8 Ohms. In early systems power selection was done in secondary circuit.
Help to identify this transformer
door gertjanrhe , Gooi, 30.03.2020, 20:42 (1699 dagen geleden) @ edison
turn ratios between the several connections can be calculated by putting an AC voltage (e.g. 6.3V of a filement winding) to one of the high ohmic coils. Simple measure the voltage over the other connections. The ratio is the ratio of in- (6.3V) and output-voltages.
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De techniek was in de jaren 40 veel verder dan menigeen zich bewust is
Help to identify this transformer
door edison , Aveiro - PORTUGAL, 31.03.2020, 23:31 (1698 dagen geleden) @ gertjanrhe
Hi.
Many thanks, to both, for the answers.
I put 10 volts in the the winding of lower resistance and got the following results.![[image]](images/uploaded/202003312129535e83b651c6b28.jpg)
Can you help me to calculate the ratio.
Many thanks.
Vriendelijke groeten,
Carlos
--
From PORTUGAL, with regards
Carlos
Help to identify this transformer
door gertjanrhe , Gooi, 01.04.2020, 22:48 (1697 dagen geleden) @ edison
The ratio of turns is identical to the ratio in voltages.
I.e. a voltage ratio 100V to 10V means a turns ratio of 10 to 1.
For the impedance transformation you have to calculate the square of the turns ratio.
I.e a turns ratio of ten means an impedance ratio of 100.
Given the ratios you measured I think it is right to say it is line transformer for 70/100V public address (PA) systems![[image]](images/uploaded/202004012047575e84fdfdb5c67.jpg)
.
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De techniek was in de jaren 40 veel verder dan menigeen zich bewust is
Help to identify this transformer
door edison , Aveiro - PORTUGAL, 05.04.2020, 19:10 (1693 dagen geleden) @ gertjanrhe
Hello.
Many thanks for your help.
The explanation is very good and now I understand perfectly.
Best regards.
Carlos
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From PORTUGAL, with regards
Carlos