Uni-Byte 0171 - Isolated MOSFET power DRIVER Part 1
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- เผยแพร่เมื่อ 30 ก.ย. 2024
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Two part series to design and build an optically isolated MOSFET power driver module for real world control of larger devices with digital controllers. In this part we look at the design. In part 2 we will build one and test it out!
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Part 2: • Uni-Byte 0176 - Isolat...
Nice useful little project, awesome....cheers.
Thanks 👍
Op-Amp can be used as a isolated -buffer.
An OpAMp would provide buffering, but not isolation. For proper isolation you need to have no galvanic connection between the isolated parts.
do you have any of your boards available on shared projects?
Some, which in particular were you interested in?
This video is very timely, for me. I am designing a similar project and you covered all of the design considerations that I have encountered. My design goals... To create an Individual Isolated Universal/NPN-MOSFET H Bridge Stepper Motor Driver Board. This is a big name for a small board that only contains an optocoupler and a NPN MOSFET. Meaning, I will be using NPN-MOSFETS on both the low and high side of the Stepper Motor load... To emulate the PNP for the high side, I will be adding a Boot Strap, which may be used, or left unpopulated, for NPN/Low Side use. You will recall that I am self taught... My present prototype board mistake was to configure the optocoupler to drive the MOSFET from the low side of the optocoupler transistor. And, while I know to employ a Boot Strap on the load's high side, even after watching tutorials, I really do not understand the higher gate voltage that is required, or the Boot Strap's operations. So, I look forward to the next video!
Glad I could help shine some light!
Waiting for part 2.
See you there!
Looks like a cool project buddy!
Above my scope, but will be here to watch it!
Thanks!
Interesting but MOSFET with a higher max. gate source voltage are very extremely rare so in the end you will need an other circuit. For anyone building this circuit: add a 10 V zener between gate and source to limit the gate voltage.
Yes, if you wanted to use for controlling voltages over 20V.
@@uni-byte Yes, but your explanation is that you don't need an other circuit but an other MOSFET if Vin is > 20 V which is incorrect. I also don't understand why you didn't take advantage of the opto-coupler to build a normal open circuit. The MOSFET is on when not driven... A strange choice and probably confusing for some.
@@foobarables I'll go along with that. As I said in the discussion (or maybe in part 2) this is a circuit I have used before and was designed for one of those uses. However, I have used it for multiple applications. But I guess you are correct, it might confuse some. Maybe I'll take a "Version 2" stab at this at some point. I tend to re-use things that work as long as the application is within the device/module envelope of operation. There are benefits to that philosophy that I'm currently trying to get across in some of my recent videos. Thank for your input, it's good information.