The alternating current changes the magnetic field and is a requirement for a normal transformer to work. Alternating current in and alternating current out.


To get direct current the output of any transformer must be processed.


Now to add some clarity. There are all kinds of items available that can do whatever you want to do. Direct current to direct current. Alternating current to direct current. Direct current to alternating current.


With a lot of items today being really voltage specific you may also need to seek out a device that also gives a regulated output. Or you can damage things.


Fortunatly most of the simple needs can be serviced quite cheap with Chinese built devices on ebay.


There are several things you must know before ordering though. The expected load the device services is really an important one. Plus of course both the voltage output and input required for the device.


I keep an assortment of alternating current to direct regulated voltage units on hand. They are less than 10.00 each delivered for the lower current ones and fully regulated and protected internally.


I was thinking just the other day that I grew up in the more mechanical world than exists today. The transformer is far from obsolete but has been passed over in your application to some degree. They have always had a problem inherent with them. The amount of load determines the output voltage. For example. If you purchased a 110 to 12 volt transformer. with very light loading 15-17 volts output may be present.


What is interesting in many ways a totally uneducated English man for all practical purposes discovered most things that enabled what I grew up with to exist. Then sometime in the 1960s an electronic revolution started and seems to be continuing.


Things like cellphones than are taken for granted today are really pretty complex devices.


Back in the day when I was sitting at my bench repairing the early transistorized equipment I could not have forcast the amount of evolution that has occurred. It was so easy back then I could repair about four items an hour at times.


What is equally amazing with no electronic knowledge other than how to use a meter today. Many people can repair their flat screen televisions. At the same time periodically I open up other current electronic devices occasionally and for all practical purposes they are not repairable.