hi all i need help on how to make own 5v 2000ma Vdc power supply...
What's the power source?
i had 24v 14 amps power supply and need to reduce it to 5v 2a
Google "DC-DC converter", or better still,avoid the hair loss and get one off eBay
You can use circuit like this
or you can get it from eBay for just under USD $3.0
Hi.
The Voltage into the DC-DC will be 24V(RMS) x 1.414= 33.9Vdc
Check to see if the converter will withstand that, also because the 24V is rated at 14Amps, with 3A load the 24V will be higher.
That is more than 33.9Vdc input.
The max input is 45Vdc.
Tom........ 
Are you sure zamir have AC as input?
Pelle
Pelleplutt:
Are you sure zamir have AC as input?
Tom is presuming/ suspecting it is unregulated and nominal 24V, from a transformer-rectifier-capacitor which if unloaded, will rise to the peak value.