I have transformer which input AC 220V (50-60Hz) and output voltage is 48V DC 130 Amp. Could I use this transformer in my 5V DC 2Amp device? For your information I use another circuit for downgrade voltage from 48V to 5V DC. I can't downgrade the Amp. Have there any option to downgrade this 130 Amp to 2 Amp?

 

Yes you can downgrade the voltage to 5V using a regulator or buck converter like L7987, the current will limit itself.

 

Yes you can downgrade the voltage to 5V using a regulator or buck converter like L7987, the current will limit itself.

I am already downgrade my voltage 48V DC to 5V DC. But I am aware of Amperage (130A). Where my devices need 5V DC and 2A. With downgrading the voltage what happen the current (Amperage)?

 

Your circuit will only draw what current it needs,

you cannot force current into a load with a fixed voltage.

 

I am already downgrade my voltage 48V DC to 5V DC. But I am aware of Amperage (130A). Where my devices need 5V DC and 2A. With downgrading the voltage what happen the current (Amperage)?

Apply Ohm's Law:

I = V/R

V = 5V
What is the resistance of the load?
If the resistance is 2.5Ω
I = 5V/2.5Ω = 2A

That is the amount of current the 5V power supply will have to deliver. The 48V supply will adjust its current automatically to provide this amount of power, with its efficiency taken into consideration.

 

Apply Ohm's Law:

I = V/R

V = 5V
What is the resistance of the load?
If the resistance is 2.5Ω
I = 5V/2.5Ω = 2A

That is the amount of current the 5V power supply will have to deliver. The 48V supply will adjust its current automatically to provide this amount of power, with its efficiency taken into consideration.

 

Thank you so much. Let my try. Your answer is acceptable.

 

It's like you car battery.
It can deliver hundreds of amps, but each load only takes the current it needs.

 

48V and 130A? I doubt it. You could barely lift that transformer.

Reducing the voltage from 48V to 5V is not efficient. Find a more appropriate transformer.

Bob

 

Thank you Bob. This is my Sony HiFi 200watt sound system. I found there is a big and quality transformer (made in Japan). And I have 30 pcs (media converter) device which need 5 VDC and 2 Amp. Now I use separate adapter for each device. But I want to use a single AC input (200~240 VAC, 50~60 Hrtz) and I want to use >50pcs (media converter) device. I already make a drop down 48 VAC to 5 VDC circuit. But I am confuse to using this output current. If you sure that this high Amperage not effect any process, just let me know this.