|Created||December 09, 2019|
|Last modified||December 09, 2019|
|Tags||buck buck-regulator converter lm358|
Buck regulator using LM358 and MOSFETTs for switching. Includes voltage and current limit control
Provides 0v-20v DC with current limiting function from 24v and 5v DC input
M1, D1, L1 and R7 will determine the max current.
R7 is the sense resistor so should be able to handle getting hot since it can be dissipating over 10w of heat at 10a loads
D3 should give somewhat of an indication when current limiting is applied
The circuit employs M2 as a signal inverter as well to be able to drive a high power MOSFETT from a 5v signal but this also means that the switch will be normally closed if the op amp circuit fails and might cause an issue if you care about that.
The main logic of this circuit is the op-amp will turn off to raise the output voltage and turn on to lower the output voltage. This allows to combine voltage and current limiting without more logic I think. Since this circuit acts as an oscillator the frequency is limited by C3
Due to the high capacity of C2 it's possible when changing load or adjusting voltage/current that it delivers more voltage/current than desired for a short time, could probably improve on the output filtering but I opted for large capacity in cases when I wanted more current
Strongly suggest using active cooling for M1 and D1. M2 should have passive heatsink
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