that's not as easy as you imagine... you may need a PID algorithm (there's a library)a simple voltage divider with a big (in both senses) resistor on the upper side may work but safety remains a concernyou may need an optocoupler and a P-channel mosfet on the 130v+ line for switchingif you are trimming a solar system you are wasting a HUGE amount of precious power
a regulator without a feedback???
The thing that I am struggling with is... How can I detect the source voltage?? I know that the lowest it will ever be is 100vdc and I know the highest it will ever be is 130vdc, and it can be anywhere imbetween these two values. Please help me understand how I can get my arduino board to detect the exact voltage that the source voltage is at any time?
It makes sense, but I don't think it will work that easily. Will your LED driver tolerate 130V pulses? You can approximate a 36V supply by feeding a capacitor. But the pulse width required will vary greatly with load. Is your LED light source variable? And even if not, would you build in a way to "unload" the capacitor?
I kind of left my question vague at the start of this thread for this reason.. I really just wanted the answer to my voltage sensing question without having to explain every other detail about the system.But since I've got my answer, I guess I can humor the rest of you and discuss my whole circuit.To answer your question.. I will basically be buildling a "switching voltage regulator". In order to get my switching regulator to output the most stable 36 volts possible, I needed to know the supply voltage being fed to it. Now that I know how to accurately detect the source voltage with the arduino, I will be able to make a switching regulator that will use this information when creating the 36 volts dc.It doesn't matter weather my LED load can handle 130vdc pulses.. The load will never see those pulses. What the load sees will be a smoothed out version of the pulsed supply voltage. This will be accomplished with appropriately sized capacitors and inductors, or simply a low pass filter. Much like how an AC waveform is rectified and smoothed to create DC voltage.. The PWM pulses can be smoothed as well.
I will basically be buildling a "switching voltage regulator".
Is there a compelling reason to roll your own rather than buy one?