Yeah, but Crystalonics only has them in TO-39 metal cans. What I find most appealing about the KP903A is that it's a stud mount.
se
Yes, TO-39 less convenient, but can also be adopted by specially designed heat sink. Surface area of even TO-39 case is enouth for dissipating 5W via thermal grease. By the way, there are also russian version of these jFETs in TO-39 case, they are noted as KP601A.
Yeah, but just drilling and tapping a hole is much simpler and elegant. 😀
Since I only need to dissipate about 2 watts, I could probably just get away with using a pair of CP650's and some clip on heatsinks.
se
Vladimir
sorry to bugging you 😉
are those КП903А or КП903Б , and what's differences between these two types ?
I'm not so good in searching Russian language sites
sorry to bugging you 😉
are those КП903А or КП903Б , and what's differences between these two types ?
I'm not so good in searching Russian language sites
Yes, the types are indicated correctly, the 903A is the best type , the 903Б has lower transconductance and higher noise, the 903B even more higher noise.
I enclose datasheet in russian, for the case if you manage to read it somehow.
I just have measured output power of this jFET buffer (with preamp connected, 20dB voltage amplification). With 7,2 Ohms resistive load it gave 4W undistorted 1kHz sine signal at the output.
Enclosed is also the sine signal at clipping condition, 1kHz frequency. There are no sharp edges.
Enclosed is also the sine signal at clipping condition, 1kHz frequency. There are no sharp edges.
Attachments
I'm sure a lot of people would be interested to try these jfets out. A group buy organized by someone in Russia/Ukraine would be nice. I'd definitely like to have a look at these devices. Thanks for showing us your circuit, Vladimir. I'm trying to get some from Russia right now... but don't know if it'll work.
Are you able to, and have you run a curve trace on these to see how linear they look?
_-_-bear
Ok, I just found the data sheet for the CP650 device, a "new" in 1976 power jfet.
The RDS on is ~5ohms.
The max vds is ~20v
The CP650 are apparently somewhat available in the USA at not so high a price... fwiw.
However these are in "T0-5" metal cans... although they rate them at 8 watts, it's unlikely that they will handle that much power for very long in that case.
Wonder if we can have a better look at the KP903's case? Maybe with something along side to see the size?
Thanks...
_-_-bear
The RDS on is ~5ohms.
The max vds is ~20v
The CP650 are apparently somewhat available in the USA at not so high a price... fwiw.
However these are in "T0-5" metal cans... although they rate them at 8 watts, it's unlikely that they will handle that much power for very long in that case.
Wonder if we can have a better look at the KP903's case? Maybe with something along side to see the size?
Thanks...
_-_-bear
Yeah? From whom?
Yeah, well the 8 watts is for a Tc of 25C.
Here's a datasheet Vladimir was kind enough to send me the other day.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
se
ummm... Mouser according to a link on the datasheet page I found, with the Mouser pricing... fwiw.
PM me if you want to maybe split an order - BUT the power handling has to be far less than the Ruskie part due to the case and pins... imo.
_-_-bear
PM me if you want to maybe split an order - BUT the power handling has to be far less than the Ruskie part due to the case and pins... imo.
_-_-bear
Sure that wasn't from back when the Mouser catalog was barely half an inch thick?
I just checked Mouser's website and the only thing "cp650" brings up is a set of pens.
And the only active producer of them according to PartMiner is Crystalonics. Crystalonics wants $17.25 a pop for 'em in 1-99 quantities and $15.25 for 100 pieces and up.
Yeah, I'm aware of that. Would really like to get the Russian part. But if the US part can be found somewhere for a reasonable price, then paralleling a couple would be a viable option.
se
I think the Mouser pricing was just some Mouser ad that cues in on part numbers.
So that leaves Crystalonics.
se
So that leaves Crystalonics.
se
Oddly, maybe, americanmicrosemi.com lists KP903A on their website:
Kp903a Spec Sheets Details Diodes, Transistors, Thyristors, Triacs, Diode Array, Integrated Circuits and Semiconductors — Product Line
But it looks like no stock and they would have to make them for you. I didn't bother requesting a quote.
Kp903a Spec Sheets Details Diodes, Transistors, Thyristors, Triacs, Diode Array, Integrated Circuits and Semiconductors — Product Line
But it looks like no stock and they would have to make them for you. I didn't bother requesting a quote.
The SITs differ from regular power Jfets in that the "linear" or "ohmic"
region extend throughout the entire load line. The regular Jfets leave
this region where Vds exceeds 2-4 volts.
Both types are a single fat Jfet with high surface area.
😎
- Status
- Not open for further replies.