[Guide] Graceful shutdown switch without Pololu [RETIRED]

[Camble]

@RxBrad Same thing happened to me, man. But I was able to get them to work by switching the Source/Drain.

[RxBrad]

@Camble I actually just read a discussion on Reddit today about how a lot of Chinese eBay/AliExpress FETs are either counterfeit or totally different components with the info sanded off and different identifiers silkscreened on.

Maybe I'll luck out and it'll be a different FET that works.

[Camble]

@RxBrad That would explain a lot...

[Quatrerwin]

Are official Fairchild JFETs a problem then with the original schematic? I was reading the datasheet for their JFETs and it says the source and drain are interchangeable.

[Camble]

@Quatrerwin I've read that too, but looking at the datasheet I can't tell if it's just the surface mount version that applies to. Anyway, I've got Fairchild JFETs working with the source and drain reversed.

[Quatrerwin]

I will be trying it either way! I got a few different brands of JFETs on the way to test. Looking to make a few pcbs that include this plus a few other features to save some space.

[RxBrad]

So, I tried the latest batch of Fairchild 2N5460 FETs I got a couple days ago. They work exactly as advertised. So, apparently the 2N5460 and 2N5461 FETs I ordered from Jameco here in the US were fakes.

Photos below. The working FET is the one on the right in both pictures. Fakes are the two on the left.





Grrrrr..

[WoodMill]

Went to Fry's with a shopping list of stuff, and of course they didn't have those FET's, or whatever they are called.

I've got your PCB pre-ordered. I think I bought it without knowing all about it. Now that I've gone through and understand more, am I just assuming it's the board, and doesn't come with any components other than the switch? With how hard these FET's seem to be to find, any chance you could throw one of those in so that we don't have to spend $8 just to get one shipped?

*Edit* And sorry if this was mentioned. I didn't go through all 22 pages to find if it was talked about.

[Camble]

@RxBrad Good to know though!

@WoodMill Unless you've asked ordered a pre-assembled one, all you'll need to do is solder the switch to the board (which is included). Everything else is ready to go. The board will also accept your original DMG-01 power switch, if you'd prefer to use that.

[spoiler="See here"][/spoiler]

[WoodMill]

@RxBrad Good to know though!

@WoodMill Unless you've asked ordered a pre-assembled one, all you'll need to do is solder the switch to the board (which is included). Everything else is ready to go. The board will also accept your original DMG-01 power switch, if you'd prefer to use that.

[spoiler="See here"][/spoiler]

Okay. Cool! I can do that. After I looked back at the thread, I was reading it as something similar to what Helder did with his Low Pass Audio board and low light indicator board. Where you just get the board with easy to follow placements of the parts, which you'd have to get yourself.