Electronics > Projects, Designs, and Technical Stuff

fast switching high current power supply

(1/4) > >>

vixo:
I've been tasked with building a power supply, it must be 10A, switch at 200kHz into a low resistance / inductive load and be very accurate! What existing equipment uses a power supply like this? Does anyone know resources I could look at to get me started? Playing around in ltspice I can get near but finding it hard to fulfill all criteria.

T3sl4co1l:

"Fast" -- how fast?  200kHz might be the repeat rate, but how quickly does it need to settle when switched?

"Low resistance / inductive load" -- how resistive, how inductive (range for each)?

"Very accurate" -- how much? And within what time frame?

Is it always 10.000..A exactly, or is this the maximum of a range? What's the minimum, and what error is allowed down there?

Likewise, when switched off, how fast and accurately does current/voltage need to go to zero?  What threshold counts as "off"?

This is a very unusual set of requirements, and it's likely you need something else entirely.  If you can start at the beginning -- describe what you are doing and why -- likely a better overall solution can be proposed.  For example, maybe output level doesn't need to be accurate at all, it just needs to be measured (either self-calibrated, or adjusted gradually over time as a feedback loop).  Maybe RF analysis techniques can be applied (e.g. to measure load resistance/inductance or real/reactive power), or other industrial solutions (e.g. induction heating power measurement).

Tim

Marco:
I'm going to guess you want something like this :
https://www.researchgate.net/publication/263679196_Constant_Voltage-clamping_Bipolar_Pulse_Current_Source_for_Transient_Electromagnetic_System

The Us voltage in the paper needs to be an adjustable power supply and is calibrated to set the pulse current (will drift, needs a control loop). Making it unipolar isn't too difficult.

vixo:

--- Quote from: Marco on June 19, 2024, 02:27:48 pm ---I'm going to guess you want something like this :
https://www.researchgate.net/publication/263679196_Constant_Voltage-clamping_Bipolar_Pulse_Current_Source_for_Transient_Electromagnetic_System

--- End quote ---

thanks! that's very interesting. I will take a closer look this week.

--- Quote from: T3sl4co1l on June 18, 2024, 06:23:24 pm ---Well, start with numbers.

"Fast" -- how fast?  200kHz might be the repeat rate, but how quickly does it need to settle when switched?

"Low resistance / inductive load" -- how resistive, how inductive (range for each)?

"Very accurate" -- how much? And within what time frame?

Is it always 10.000..A exactly, or is this the maximum of a range? What's the minimum, and what error is allowed down there?

Likewise, when switched off, how fast and accurately does current/voltage need to go to zero?  What threshold counts as "off"?

This is a very unusual set of requirements, and it's likely you need something else entirely.  If you can start at the beginning -- describe what you are doing and why -- likely a better overall solution can be proposed.  For example, maybe output level doesn't need to be accurate at all, it just needs to be measured (either self-calibrated, or adjusted gradually over time as a feedback loop).  Maybe RF analysis techniques can be applied (e.g. to measure load resistance/inductance or real/reactive power), or other industrial solutions (e.g. induction heating power measurement).

Tim

--- End quote ---
I can't be too specific. I'm designing a unipolar voltage controlled transconductance stage which delivers between 0 and 10A. It needs to settle within 5uS and be accurate to.. hmm lets say ideally 1ppm, with very low noise and very low drift. My colleagues would get very impatient very quickly if I start trying to come up with other ideas, I'm just enquiring in case someone case seen or has experience with something in this ball park.

Phil1977:
Laser diode controller?

Not just as a question, maybe also as an idea where to find these qualities.