Hi-Voltage JFET's


Current regulating diode=Constant current diode

A normal PN-junction diode is included in series with the JFET to protect the transistor against damage from reverse-bias voltage, but otherwise the current-regulating facility of this device is entirely provided by the field-effect transistor.



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how about clicking the ´English´ button in the menu of the Site?


The funny thing is that КП926А(Б) are in production as we speak... ТО-3 BTW
NOS are $10 apiece
I've talked to the manufacturer just lately. Moreover there are lower voltage parts...
Attached is current datasheet
P.S. There is nothing in english version of site


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Hi Alex,

I´m very much interested in those parts, but totally lack russian language capabilities. Still though I mangaed to track the devices to a company that might be the manufacturer, but this companießs Website doesn´t tell anything about them manufacturing SITs. I asssume there´s no english translation of the Datasheet and some more infos available/possible? Do You happen to know a company or distributor contact?

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but it seems like does not need gate positive voltage biasing,
which reminds biasing of tubes and njfets,
so what that it is not jfet when it acts like jfet? maybe slightly different transconductance curve which is more like pentode...:confused:
anyway I am going to build Aikido with them:cool:
The "KeyPi"926 is SIT(static induction beast) like a SS triode
simple JFET is a SS "pentode"
Deplition mode MOSFET has particular input capacitance "feature" dissimilar to one of junction based devices
Lateral MOSFETS are better then "standard" vertical double diffusion MOSFETs
The "KeyPi"926 is SIT(static induction beast) like a SS triode
simple JFET is a SS "pentode"
Deplition mode MOSFET has particular input capacitance "feature" dissimilar to one of junction based devices
Lateral MOSFETS are better then "standard" vertical double diffusion MOSFETs

but vertical types are used in many good amps
and of course if you do not like them
do not use them;)
I will:cool:
They're HERE!
SiC Transistors | Semisouth Laboratories, Inc. :D

(It is interesting to compare the characteristics of V-JFET and SIT - SIT is more triode-like and uniform.)
SIT Power Amplifier - this page starts with readers' complain about the difficulty of finding the 2SK180 (in Japan!). Again, the B2B sites will tell you, if it still available...
As it was mentioned before (on this forum and elsewhere), there are several companies working currently on the development of Silicon Carbide SIT. Yes, the interest is there. But, it will take time...
It is also looks like the memory of HV/Power JFETs of the '70's is not going away:). Those were Vertical JFETs with output characteristics of "triode" type (very low output impedance), as opposite to all other JFETs and MOSFETs with "pentode" type characteristics (high output impedance).
Those compl. pairs are:
2SJ18 - 2SK60, ~63 W, 170 V, Sony,
J19 - K69, 800 mW (at 150°C), 140 V, TO-5, NEC
J20 - K70, ~100 W, 100 V, NEC
J21 - K71, 15 W, 160 V, TO-66, NEC
??? - K75, TO-66, Yamaha
J26 - K76, ~100 W, 200 V, Yamaha
J27 - K77, ~100 W, Yamaha
J28 - K82, ~100 W, 240 V, Sony
J29 - K89, ~100 W, 110 V, Hitachi
J38 - K98, from Yamaha, used in their organs, so organ repair services may have it. (I hope, they are complimentary).

There was a complementary of the Yamaha K75, J25. It's not actually not truly complementary, rather a P-ch part with the same basic voltages and currents but lower mu.
I think, it will be a good idea to modify the list in my post #26 to include the following changes:

??? next to K75 need to be replaced with J25, to form a pair,
Add line: J24 - K78, TO-39, Yamaha -right before that pair, naturally.
The entry for J19... need to be modified as: TO-39 (metallic bottom), not TO-5.
Entry for J27... need to be corrected as: 200 W.

Also I will mention two curious facts of the V-FET story.

Several years ago someone in Europe was offering on E-bay 2SK69 (NEC parts) marked as
Toshiba (in italics), just like we have seen so many real Toshiba old metallic parts were marked!
While Toshiba did have cooperation with NEC in the different areas of business at that time,
and did make several NEC transistors, marked as TEC (=Toshiba), and having help from NEC
in the V-FET development, some things I have found questionable:
The surface of their TO-39 cases instead of having smooth and shiny surface actually had
grainy spots.
Very suspicious that Toshiba QC would let these defective parts out the door.
In our communication with the seller he even stated:
"My wife is Chinese and she say that these transistors are genuine".
I have found his attitude not being trustworthy, and that was the end of the story...

Another similar story: long lost Japanese picture of a bunch of the Sony V-FET (K60 or J18? -do
not remember exactly) having a few among them marked as Hitachi, and having distinctive
Hitachi case (slightly spherical top), and nothing suspicious.

Go figure...