current control by microcontroller

hi all

i have a simple circuit in which the light bulb intensity control is done by varying the resistance.i am using a ready module in which the input is DC and i control the current by using a 10K pot. now i want to remove the 10K pot and instead want to use a microcontroller circuit which would control the current. i know it would require DAC and all...

can some one please help me out how to proceed and how is it possible?

Easily possible, and simple to do - like you say a DAC is all you require, and you could use PWM to create one with a single resistor and capacitor, depending on the input requirements of the module.

Nigel Goodwin said:

Easily possible, and simple to do - like you say a DAC is all you require, and you could use PWM to create one with a single resistor and capacitor, depending on the input requirements of the module.

Click to expand...

i did not get you much. what will be the output of the microcontroller which i have to give to the DAC . also DAC would give me some dc voltage . how will i control the current then?

I presumed you needed a variable voltage, perhaps you should post a diagram of exactly how it's currently connected?.

Hi,

Im trying to use a current limiting circuit similar to the above (varied using a microcontroller) to simulate a PV cell.

Was wondering if the circuit you have mentioned can be modified to be used in this way (ie. as a variable resistor which gives a constant current to a certain voltage limit before the current drops away?)