FirstWatt J2

[Magura]

Originally Posted by Nelson Pass

I've been clear on this - the schematics of the J2 will be
released when production ceases. I'm tired of the
commercial clones using my trademarks, claiming to be
accurate reproductions.

In the meantime, you should have enough smarts to cobble
together your own versions based on the simplified
schematics. Much more fun that way.

Quite understandable, no-one should put up with that.

And we will supersede you anyway


Magura

[mos57]

Hello, please sign me in this group buy also.

Francesco.

[NihonJR06]

Me too

Please sign me in this group buy

Domo arigato
Sensei PASS

[Magura]

Originally Posted by NihonJR06

Me too

Hold your horses boys.....I have some crying and threatening to do tomorrow



Magura

[zhoufang]

Originally Posted by Magura

I tried that, but they are not sharing well. I have a test setup where this was supposed to bring some fun.
No fun so far, just blown devices.


Magura

How close did you match your device?
How close were the parallel devices thermally coupled with one another? (the thermal resistance between mounted devices)
Maybe the device's Id just increase too much for the same Vgs with increasing temperature (which is likely, as it is a very high gm device), thus easily go into thermal runaway.
I have no idea how bad is the thermal run-away tendency, as the datasheet does not include Id vs Vgs graph for different temperature, and I do not have a single device on hand to test it myself.

BTW, count me in if there is a GB.

[Magura]

Originally Posted by zhoufang

How close did you match your device?
How close were the parallel devices thermally coupled with one another? (the thermal resistance between mounted devices)
Maybe the device's Id just increase too much for the same Vgs with increasing temperature (which is likely, as it is a very high gm device), thus easily go into thermal runaway.
I have no idea how bad is the thermal run-away tendency, as the datasheet does not include Id vs Vgs graph for different temperature, and I do not have a single device on hand to test it myself.

BTW, count me in if there is a GB.

They were matched within 10mV, mounted on a copper bar.....trust me, we have the same idea, I just had it a while ago

Thermal runaway just seems hard to control with those critters.


Magura

[Tea-Bag]

Magura, Good luck,
If there is a GB count me in.

[Magura]

Originally Posted by Tea-Bag

Magura, Good luck,
If there is a GB count me in.

There is for sure


Crying may not do, but the threats....oh boy


Magura

[Melon Head]

Well, I am a sucker for a group buy. So put me in the list too.
It is going to be expensive though. I suspect at the very least $30 each, and how many do we need to get nice matched pairs.

[Tea-Bag]

Originally Posted by thanh1973

Well, I am a sucker for a group buy. So put me in the list too.
It is going to be expensive though. I suspect at the very least $30 each, and how many do we ned to get nice matched pairs.

Do we need matched pair in Mu follower design?