Voltage source with Current rating and Current through Resistor

[Chucker]

Hi,
If I have a Voltage source 24V 500mA and have a couple of resistors in series connected to a Load, should I use the current from the Voltage Source to do calculations or should I use I=V/R formula to get the current flowing? Which is the rule of the thumb here? I am novice to practical electronics. Please help

Thanks
Chucker!

 

[Electronworks]

What are you trying to do?

The voltage at the end of your 2 resistors will be 24V until you put a load on them (I assume your load is to 0V). Then, the current flowing will be 24/(R1+R2+Rload). The voltage across your load will then be this current multiplied by Rload.

This is a poor method of regulating voltage though, because if your load changes the voltage across it changes.

 

[Chucker]

But why do they give rating on the Stepdown transoformer as 24V 500mA?
what does this current rating mean at all, if we are to calculate the Current using V/R?

Thanks in advance
Chucker

 

[mbarazeen]

your transformer is capable to deliver 500mA, thats the meaning of the curent rating. the voltage is the one you should use to do your calculation. but make sure final I (=V/Rtotal) doesnt exceed 500mA.

when your load is less ie more resistance then your load current will be less.

there are current sources (what you have is a voltage source) when you use a current source regardless of your load it will push the set current through your load (within the limit).

 

[Chucker]

Ah, Thanks for the response
Got you