hi, how are you.

I am such a beginner in electronics so I'd be very grateful if someone can help me.
I have to build a simple power supply that work with an input of 220v AC and has an output of 1A and 12V DC. I have to build the circuit in two deferent ways:
1-with transistors
2- with LM723

thank you !

 

So...what's the question?

 

can anyone help me building these circuits?

 

googling can find u lot's of circuits.
find one, post it, and then we can discuss it.
do ur home work first

 

i have google it but i did not find anything similiar.
anywhere , thank you !

 

U want a series regulator and an IC regulator.
try these for series regs

 

The first thing you need is a transformer to drop the line voltage to a safe level. And a level closer to your end result.

If you look at the datasheet for the LM723 you will find its input voltage range.

You need a transformer that will drop the voltage to about 2 volts above that number.

One of the reasons you want it a few volts higher, is you will be needing a bridge rectifier to convert the AC to DC.

Bridge rectifiers use diodes to do the work. As we all know, diodes will drop the voltage a certain amount. So, you have to be sure the starting voltage on the secondary of the transformer is high enough.

 

Hello,

Perhaps this circuit will interest you:
http://www.zen22142.zen.co.uk/Circuits/Power/723psu.htm

It is a link from this EDUCYPEDIA page on powersupply links:
http://www.educypedia.be/electronics/circuitssupplies.htm

Bertus

 

thank you very much to everyone )

 

Basic Bench Top Power Supplies

 

The first thing you need is a transformer to drop the line voltage to a safe level. And a level closer to your end result.

If you look at the datasheet for the LM723 you will find its input voltage range.

You need a transformer that will drop the voltage to about 2 volts above that number.

One of the reasons you want it a few volts higher, is you will be needing a bridge rectifier to convert the AC to DC.

Bridge rectifiers use diodes to do the work. As we all know, diodes will drop the voltage a certain amount. So, you have to be sure the starting voltage on the secondary of the transformer is high enough.

thanks v much for such brief explanation