I don't know how to use a buck converter....

[David lopez]

you are suppose to be able to vary the output current of a buck converter. how do i vary the output current of a buck converter? i am just trying to make sure i know how to use a buck converter.

 

[davenn]

you are suppose to be able to vary the output current of a buck converter

no, not if it isn't designed for that purpose

how do i vary the output current of a buck converter?

Unless the buck or boost converter specifically has a current limiting circuit as part of it,
most don't, the output current will be determined by the load

 

[davenn]

i am just trying to make sure i know how to use a buck converter.

so what buck converter IC have you chosen to use ?
Have you looked at the datasheet and determined how it is used ?

 

[David lopez]

so i connect the buck converter to a load, which means it has resistance, and the resistance of the load determines output current?

 

[davenn]

so i connect the buck converter to a load, which means it has resistance, and the resistance of the load determines output current?

Yes
So, it is then important that the load will not try to draw more current than the converter (buck or boost)
is capable of supplying, else you will let out the "magic smoke"

 

[David lopez]

so what buck converter IC have you chosen to use ?
Have you looked at the datasheet and determined how it is used ?

i didn't settle on any particular model. instead i looked at different models. the seller listed the specs. for example he stated input voltage, output voltage, output current. the seller always gave me a range of current values. so i wondered how do i adjust output current.

 

[David lopez]

have any of you used prebuilt buck converters?

 

[alan123hk]

how do i vary the output current of a buck converter?

What does it mean to vary the output current of a buck converter?

If you use a prebuilt buck converter with a fixed output voltage, the only way is obviously to change the load resistance as long as the output current is still within the rated range.

Also for regulated voltage output converters, the specified current should be the rated maximum output current, rather than supplying a specific amount of current to the load.

 

[davenn]

have any of you used prebuilt buck converters?

yes, pretty much the only way I use them. Is extremely rare that I will build one up from scratch
it's just too much work when they are so cheap on ebay and other places

 

[davenn]

What does it mean to vary the output current of a buck converter?

If you use a prebuilt buck converter with a fixed output voltage, the only way is obviously to change the load resistance as long as the output current is still within the rated range.

Also for regulated voltage output converters, the specified current should be the rated maximum output current, rather than supplying a specific amount of current to the load.

Yup, I covered all those points

 

[alan123hk]

Yup, I covered all those points

I know, I'm just trying to repeat basically the same content in slightly different styles.

 

[David lopez]

What does it mean to vary the output current of a buck converter?

If you use a prebuilt buck converter with a fixed output voltage, the only way is obviously to change the load resistance as long as the output current is still within the rated range.

Also for regulated voltage output converters, the specified current should be the rated maximum output current, rather than supplying a specific amount of current to the load.

when i look at buck converter being sold, the specs show a range of different input voltages, a range of different output voltage and a range of different output currents. according to the specs the buck converter can receive different input voltages, can have different output voltages, and can have different output currents.