how can we convert 220v AC to 15v and -15v in DC.

 

With a bipolar power supply.

 

how can we convert 220v AC to 15v and -15v in DC.

To put it simply, you need a Transformer to step down 220V AC to 15 V AC. You will need Rectifiers to convert the AC to DC and reduce the ripple using Capacitors. You may also need Voltage Regulators.

If you can tell us more - Purpose, Required Current, How steady the Voltage needs to be, etc; more advice can be given.

Ramesh

 

no matter about current. the main purpose is to get 15v and -15v in one curcuit.

 

no matter about current.

Well, good luck then.

 

no matter about current. the main purpose is to get 15v and -15v in one curcuit.

Here you are.

Ramesh

 

Here you are.

Ramesh

That circuit will give you +21V/-21V under no load, and will drop to +15v/-15V only under some undetermined full load.

Ken

 

True. Better to use a center tapped 24V transformer for an unregulated job like this.
Use the center tapped 30 volt if you are going to add regulator chips.

 

If you want to stay real cheap, then use something like this:

You would want a 220VAC:12VAC transformer.

This (or the full-wave version above with a 24V centertapped) will give you about 17V under no load but that will drop as you load it.

Just saying you want ±15VAC with no current level and no other information to go on makes doing anything more that something real rough difficult.