Oh s..t the link was wrong,
http://www.semicon.toshiba.co.jp/openb2b/websearch/resultDo.jsp
It is data for some audio JFET products from Toshiba and I guess that they also sell them somewhere I don't know and ask if any can give some hint where I can find them.
Kamskoma
http://www.semicon.toshiba.co.jp/openb2b/websearch/resultDo.jsp
It is data for some audio JFET products from Toshiba and I guess that they also sell them somewhere I don't know and ask if any can give some hint where I can find them.
Kamskoma
Hi,
i have few questions related the regulator that was discussed in this thread (made by Justcallmedad)...
Mr. Curl said that every stage of the regulators is doing something....so, LM317 is doing something to the voltage being regulated, and also the rest of the regulator circuitry doing their thing...
can somebody please tell me what to do if i have to use higher voltage than LM317 is supporting - if i need for example +/-45V out of the complete regulator....??.... should i stick to the LM317 or change to something else - maybe series regulator or something???
also - second question - would it not be better to substitute JFET ccs's with bjt ccs's??....maybe parts are easier to find ???
thanks for any replies...
sunny
p.s. sch attached again
i have few questions related the regulator that was discussed in this thread (made by Justcallmedad)...
Mr. Curl said that every stage of the regulators is doing something....so, LM317 is doing something to the voltage being regulated, and also the rest of the regulator circuitry doing their thing...
can somebody please tell me what to do if i have to use higher voltage than LM317 is supporting - if i need for example +/-45V out of the complete regulator....??.... should i stick to the LM317 or change to something else - maybe series regulator or something???
also - second question - would it not be better to substitute JFET ccs's with bjt ccs's??....maybe parts are easier to find ???
thanks for any replies...
sunny
p.s. sch attached again
Attachments
now the same for serial resistance 0.01 ohm to 0.1 ohm, step 0.01ohm. From these 2 images one can see that for a given example, the best situation is for 0 ohm, then spectrum worsens for increasing resistance to 0.1ohm and then again gets better for resistance between 0.1 and 1 ohm. This is only one example and one analysis approach, but it shows that there can be not negligible difference depending on what is placed before the power supply.
Attachments
Grey,
I am sure that John will answer you. If you do not mind, I would bring my point of view:
1) there is an interference case from mains line. In consequence, every modification we make on primary side reflects at secondary side and changes conditions of self-noise of the rectifier circuit, coupled to transformer (see my plots, additional inductance brings problems similar to resistance).
2) for power amplifier, we may not "soften" the circuit, that means every real impedance in series with transformer is again best avoided.
Regards,
Pavel
I am sure that John will answer you. If you do not mind, I would bring my point of view:
1) there is an interference case from mains line. In consequence, every modification we make on primary side reflects at secondary side and changes conditions of self-noise of the rectifier circuit, coupled to transformer (see my plots, additional inductance brings problems similar to resistance).
2) for power amplifier, we may not "soften" the circuit, that means every real impedance in series with transformer is again best avoided.
Regards,
Pavel
Just look to the power line itself. That is enough to see that a 10uf cap can reduce the residual garbage that it picks up from switching supplies, etc. Actually, this cap only reduces the garbage. Above 100KHz or so, the series inductance of the cap and its wiring, limits its effect at RF frequencies. However, the critical region in this case is between 20KHz and 100KHz, as this is where all kinds of new and interesting interference is being generated and picked up by the power line.
can someone please look at this post and reply if it is not a problem....
http://www.diyaudio.com/forums/showthread.php?postid=1304259#post1304259
thanks....
http://www.diyaudio.com/forums/showthread.php?postid=1304259#post1304259
thanks....
sunrise said:
LM317/337 can deliver any voltage you want as long as input/output difference is...look at datasheet
, and watch out for disipation, of course.Answer for 2nd question is no in this application, proper J-Fet wired as current source represents a (very) high impedance load which is good. Take a look at W. Jung site about CCS, most interesting reading.
kamskoma said:
Here's a source for the 2SJ74/2SK170 low noise FET compliments. I just ordered from them and all went very well.
http://tech-diy.com
Mike.
aparatusonitus said:
LM317/337 can deliver any voltage you want as long as input/output difference is...look at datasheet
Answer for 2nd question is no in this application, proper J-Fet wired as current source represents a (very) high impedance load which is good. Take a look at W. Jung site about CCS, most interesting reading.
o.k. - thanks aparatusonitus,
i understand - so in this application it is better to use JFET's....something like BF245C for example?
thank You for the infor related W. Jung site about CCS's....
regards
sunny
mpmarino said:I was about to order more when I noticed:
"Regrettably, we have had to increase the price of JFET's to pass along our higher costs. Lead times for these components, 2SK170BL and 2SJ74BL are now several months."
Wow, sorry to hear that, actually I must have recieved some of the last they had. I just ordered some a week or so back.
Does anyone know what Toshiba's minimum order amount is?
Mike.
- Status
- Not open for further replies.