Uploaded September 2026 | Updated September 2026, 1 hour ago

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Why switching speed is important and how to improve it …
↓↓↓ Complete description, time index and links below ↓↓↓

In the last video we’ve covered the basics of solid state relays, building an AC capable one out of two MOSFETs with a gate discharge resistor and an optocoupler (link below). At the end I told you that a discharge resistor is not a good solution.

So we first have a look with the oscilloscope at the on/off switching times with that discharge resistor. Then we explore what switching losses are and how they can destroy your MOSFETs. Finally we accelerate the switching using a FET.

00:00 Intro – gate discharge resistors are not a good solution
00:32 Discharge resistor 1 – simple solution, slow switching
05:43 Switching losses – slow switching destroys MOSFETs
12:01 Discharge resistor 2 – between a rock and a hard place
12:49 Discharge JFET – much faster on, lightning fast off
24:38 Wrap-Up – next up are more details, bye

Tutorials youtube.com/playlist?list=PLwq-2MnM58FKn3920rc1V0qoTsQDheTIw
Solid-State Relays – The Basics youtu.be/pi92JhnbAkw
Solid-State Relays – The Details (2) youtu.be/RecJYUTf5-g
JFETs – The Dirty Details (1/3): Theory youtu.be/8ETFtddyfoE
JFETs – The Dirty Details (2/3): Practice 1 youtu.be/BtKWRsjCgDE
JFETs – The Dirty Details (3/3): Practice 2 youtu.be/VTT3ZEdfuhE

#mosfet #optocoupler #photovoltaic #tutorials #tutorial #how-to #robertssmorgasbord