yngndrw
New Member
Hi,
I'm interested in PSU design, well specific parts of it - Mainly the control / feedback.
As a project I'm looking at building a PIC-Controlled PSU. You set the Voltage / Current limits on a little LCD and it supplies this with a respectable accuracy. The PSU output would be based around PWM controlled directly by the PIC.
For this, what is the best way to work with the feedback. You would get the current Voltage / Current using the PIC's ADC, but then how would you use this information to manipulate the output - Especially since (In my experiance.) the PIC ADC's pickup quite a bit of noise.
Secondly (And slightly unrelated.), what are the best ways of reading a PIC's ADC to get an accurate value ? (In C using PIC 18F's, if it makes a difference.) Is it best to use an external ADC and if so, why ?
Thirdly, in a "normal" linear PSU with standard analogue components creating the feedback / control circuitry, what is the best way to combat voltage "droop" - I.e. The voltage drop that you get when you apply a large load.
Finally, again in a linear analogue PSU, what's the best way to control both voltage and current limiting while providing high accuracy, low droop and making the PSU "indestructable" ? (Able to withstand short-circuiting for an "infinate" period of time.)
In general I'm interested in design techniques and explanations, but example circuit diagrams are always helpful.
Thanks for any help.
I'm interested in PSU design, well specific parts of it - Mainly the control / feedback.
As a project I'm looking at building a PIC-Controlled PSU. You set the Voltage / Current limits on a little LCD and it supplies this with a respectable accuracy. The PSU output would be based around PWM controlled directly by the PIC.
For this, what is the best way to work with the feedback. You would get the current Voltage / Current using the PIC's ADC, but then how would you use this information to manipulate the output - Especially since (In my experiance.) the PIC ADC's pickup quite a bit of noise.
Secondly (And slightly unrelated.), what are the best ways of reading a PIC's ADC to get an accurate value ? (In C using PIC 18F's, if it makes a difference.) Is it best to use an external ADC and if so, why ?
Thirdly, in a "normal" linear PSU with standard analogue components creating the feedback / control circuitry, what is the best way to combat voltage "droop" - I.e. The voltage drop that you get when you apply a large load.
Finally, again in a linear analogue PSU, what's the best way to control both voltage and current limiting while providing high accuracy, low droop and making the PSU "indestructable" ? (Able to withstand short-circuiting for an "infinate" period of time.)
In general I'm interested in design techniques and explanations, but example circuit diagrams are always helpful.
Thanks for any help.
