DC Voltage Step Up/Down Converter

[karim102]

Hi,
I want to ask if there D.c device that can step up or step down directly the Voltage. If there, can you show me and give me the design.

 

[dlgoff]

To step down, use a voltage divider. To step up, you could use an op-amp.

 

[berkeman]

Hi,
I want to ask if there D.c device that can step up or step down directly the Voltage. If there, can you show me and give me the design.

Do you mean like using voltage regulators? If so, you can step down and regulate a lower voltage using either a linear regulator or a buck DC-DC converter. And you can step up and regulate a higher voltage using a boost DC-DC converter. Info on voltage regulators can be found at the manufacturer's websites, like for Maxim and National Semiconducor.

 

[karim102]

ok, but we can use something like transformer that can step up low voltage to very high voltage "20v D.C to 3000 D.c" as same as A.c transformer.

 

[berkeman]

No, there is no such thing as a DC transformer. To step up the voltage, you have to "chop" it to AC in some way. Kind of like how a flash works on a camera -- you hear the squeal as the DC camera battery voltage is chopped to make the higher DC voltage required by the flash. Also, to get to 3000Vdc, you would probably use a flyback transformer topology boost, much like TV sets use to make the 15kVdc to 35kVdc CRT bias voltage. Be careful with high voltages like that, Karim.