Current Question

[johnsz]

OK, I have a silly question but I'm sure so one can answer the question for me.

I'm trying to make a DC-DC comverter with an Input of 34VDC rated at 2 amps, and I'm thinking of bringing that down to 5VDC. My question is that would I only still have a maximum current of 2 amps or since my voltage went down will my current go up? I'm thinking of using an LM340 or somthing simular.

Thanks in Advance.

John

 

[Sebi]

When You apply a dissipative regulator as LM340, the current of output equal to input. If the input voltage is 34V, output 5V, the difference 29V,multiple with 2A load = 58W dissipation (heat on LM340).
With switching regulator from 34V 2A input You can suck from output about 6A.

 

[johnsz]

Recommended Component

I appriciate your response. What component or design would you recommend? I'm trying to keep it as simple as possible, If thats possible.


John

 

[pebe]

This is the link to a japanese switched mode power supply. It can deliver 5V at up to 2.5A from a supply of between 7 and 40VDC.

**broken link removed**

It uses a switched mode chip and just a few other bits, so efficiency is at a max and surplus heat at a minimum.