quick Transformer question.

[HerbertMunch]

Hi,
i have bought (**broken link removed**).

The datasheet says that the secondary winding is 9v+9v, and there are two sets of - and + pins on the transformer.

Can anyone tell me why this is? Do i need to connect both sets?

Many thanks,
chris.

 

[Brian Hoskins]

Basically you've got two sets of secondary windings on there. You can connect it in centre tap mode to get +9V - 0V - -9V if you want to, or you can use the windings in parallel for +9V at double the current, or +18V in series.

You don't need to use both secondaries if you don't want to, but you'll get double the current (@9V) if you use both in parallel.

Brian

 

[HerbertMunch]

nice one brian.

thanks for the quality explanation.

 

[Brian Hoskins]

I'm always happy to help if I can - hopefully it goes someway to paying back the help I ask for myself!

Bear in mind that if you're planning to full-wave rectify the output you're not going to get +9V D.C. The output of the transformer will be 9V R.M.S (A.C.) and so when you convert it to D.C. you get closer to the peak value (because your reservoir cap discharges from the peak downwards).

Brian

 

[HerbertMunch]

Ok thanks very much.