Hi Andrew,
I'm thinking it may stay latched. I admit I haven't played with it. When I get a unit in, I measure for shorts before applying power. I never really see the circuit in operation.
I think you have a good grasp on how it works. There is a little delay in operation and it is possible to overheat the outputs as well. Output failure may be caused by a combination of high temperature and current spikes, exceeding SOA momentarily. Bang!, we have wire.
There isn't very much that is blow up proof. Outputs will go, sometimes the driver goes first. Just depends on what is happening dynamically. The more you know, the more you just accept that there are things you don't know.
-Chris
I'm thinking it may stay latched. I admit I haven't played with it. When I get a unit in, I measure for shorts before applying power. I never really see the circuit in operation.
I think you have a good grasp on how it works. There is a little delay in operation and it is possible to overheat the outputs as well. Output failure may be caused by a combination of high temperature and current spikes, exceeding SOA momentarily. Bang!, we have wire.
There isn't very much that is blow up proof. Outputs will go, sometimes the driver goes first. Just depends on what is happening dynamically. The more you know, the more you just accept that there are things you don't know.
-Chris
Hi Shawn,
Allow me to apologize to you. "Verbal shorthand" for terms is always the most difficult for anyone to learn. Same for software and telephone systems. The same idea has different names, so I can understand you. BTW, I'm far from the level that some of these guys are at! I still have to struggle to understand some concepts, and that's the beauty of electronics. You are always learning.
So if you look at the combination of Q11 and Q13, that circuit provides a relatively constant current draw the the differential pair, Q3 and Q5. If you were to turn on Q15, that would remove base current from Q11. That shuts everything down. All the other circuits, from Q7 and Q9 on, depend on Q3 and Q5 to draw current. So there is no base drive for the outputs if the current sink has been shut off. That's as long as no components have become defective.
-Chris
Allow me to apologize to you. "Verbal shorthand" for terms is always the most difficult for anyone to learn. Same for software and telephone systems. The same idea has different names, so I can understand you. BTW, I'm far from the level that some of these guys are at! I still have to struggle to understand some concepts, and that's the beauty of electronics. You are always learning.
So if you look at the combination of Q11 and Q13, that circuit provides a relatively constant current draw the the differential pair, Q3 and Q5. If you were to turn on Q15, that would remove base current from Q11. That shuts everything down. All the other circuits, from Q7 and Q9 on, depend on Q3 and Q5 to draw current. So there is no base drive for the outputs if the current sink has been shut off. That's as long as no components have become defective.
-Chris
anatech said:
I take my visiting family to the airport tomorrow AM, after a little afternoon nap I'll try to digest this info. Thanks for the expanded version, I need it.
I want to move into assembly mode first and then try some extended protection, I guess it will happen at the same time.Shawn.
P.S. I'm populating these Quasi boards and I look at the silicon count on the output...damn 10 IRFP450's per channel could deliver a tremendous amount of current on a bad day! I have 927KVA transformers, this thing will rock! Now I really need some good sounding speakers with POOR
efficiency.
TomWaits said:I look at the silicon count on the output...damn 10 IRFP450's per channel could deliver a tremendous amount of current on a bad day! I have 927KVA transformers, this thing will rock! Now I really need some good sounding speakers with POOR
....or at your next bash, connect to lots of speakers (2 ohms) and party party party.
Miodrag,
I am still on my backup system (long story) so the links I have accumlated for balnced line drivers and recivers is not available. I assume you are aware of the balanced line drivers via Rod Elliot's ESP site:
http://sound.westhost.com/project51.htm
http://sound.westhost.com/project87.htm
Of course these are not the only circuits for balanced lines about. I know there are a few projects about on diyAudio as well as some good circuits about the wen if you search and screen out the usual noise factors of seach and projects you find.
Balanced line drivers is also one of the add on for my amps as well, and how to add cleaning externally to the existing commercial equipment I have that one cannot even DIY.
I would be interested in what circuit you finally decide on and the reason(s) why over the otehr shortlisted circuits you considered.
Regards,
John L. Males
Willowdale, Ontario
Canada
28 May 2006 18:43
28 May 2006 18:44 Typo correction
I am still on my backup system (long story) so the links I have accumlated for balnced line drivers and recivers is not available. I assume you are aware of the balanced line drivers via Rod Elliot's ESP site:
http://sound.westhost.com/project51.htm
http://sound.westhost.com/project87.htm
Of course these are not the only circuits for balanced lines about. I know there are a few projects about on diyAudio as well as some good circuits about the wen if you search and screen out the usual noise factors of seach and projects you find.
Balanced line drivers is also one of the add on for my amps as well, and how to add cleaning externally to the existing commercial equipment I have that one cannot even DIY.
I would be interested in what circuit you finally decide on and the reason(s) why over the otehr shortlisted circuits you considered.
Regards,
John L. Males
Willowdale, Ontario
Canada
28 May 2006 18:43
28 May 2006 18:44 Typo correction
This is the shopping list I used when I searched for suitable transistors;
2SC2546, 2SC2547, 2SC1841, 2N5550, 2N5551, 2SC1845, 2SC2003, 2SC2784, 2SC2362, 2SC1775, 2SC2856, 2SD755, 2SD756.
Yes the 2n5551 is in there but was not my first choice although I would have used it if I had to. The pinouts are different though so take care with that. Try to find some of the others and have a look at the data sheets first. Look for low noise, a Vce of 90 - 120v.
The IRF9510 and 9620 are P-channel FETs and cannot be used. You neeed N-channel FETs in a TO-247 / TO3P case. Suitable FETs are IRFP 240, 250, 350, 450 or similar.
Look for Vds of 200 volts or more, current (Id) between 10 and 20 amps, and power dissipation of 180 watts or more at 25 degC.
Cheers
2SC2546, 2SC2547, 2SC1841, 2N5550, 2N5551, 2SC1845, 2SC2003, 2SC2784, 2SC2362, 2SC1775, 2SC2856, 2SD755, 2SD756.
Yes the 2n5551 is in there but was not my first choice although I would have used it if I had to. The pinouts are different though so take care with that. Try to find some of the others and have a look at the data sheets first. Look for low noise, a Vce of 90 - 120v.
The IRF9510 and 9620 are P-channel FETs and cannot be used. You neeed N-channel FETs in a TO-247 / TO3P case. Suitable FETs are IRFP 240, 250, 350, 450 or similar.
Look for Vds of 200 volts or more, current (Id) between 10 and 20 amps, and power dissipation of 180 watts or more at 25 degC.
Cheers
Sorry I did not make myself cleared,
I don't mean using P-channels for the outputs. In the 8pcs output version, (I don't think you had post the schematic for 10pcs output version, have you? ), there are 2 pcs of IRF9620 used and I happen to have IRF9510 at hand, just wondering if I can use them in place for IRF9620.
Now the replacement list for 2sc1845 is longer, I might be able to find other Jap's transistor locally. Like I said, if I source them abroad, the S&H is really crazy. I will be careful when I am using 2n5551, I am aware of the different pin outs. I should be re-laying the boards anyway (using yours as a guide line) so that I can get more control of it when I want to change something. To be frank (and sorry, no hard feeling please), I don't like the way the 5W resistors are. I want them lying down instead of pointing up like that: should some part of my body be doing that instead of they....just kidding.
Tks for the clear instruction for how to find the replacement. This way I should not be raising my hands again (for this purpose)
I don't mean using P-channels for the outputs. In the 8pcs output version, (I don't think you had post the schematic for 10pcs output version, have you? ), there are 2 pcs of IRF9620 used and I happen to have IRF9510 at hand, just wondering if I can use them in place for IRF9620.
Now the replacement list for 2sc1845 is longer, I might be able to find other Jap's transistor locally. Like I said, if I source them abroad, the S&H is really crazy. I will be careful when I am using 2n5551, I am aware of the different pin outs. I should be re-laying the boards anyway (using yours as a guide line) so that I can get more control of it when I want to change something. To be frank (and sorry, no hard feeling please), I don't like the way the 5W resistors are. I want them lying down instead of pointing up like that: should some part of my body be doing that instead of they....just kidding.
Tks for the clear instruction for how to find the replacement. This way I should not be raising my hands again (for this purpose)
Aaah now I see where the confusion is. I think you are talking about the other amp in the thread "Another quasi-complimentary design".
http://www.diyaudio.com/forums/showthread.php?postid=595571#post595571
A version of this amp uses the IRFP9620 in the second stage as part of a cascode. The main thing you need to worry about this FET is the Vgs which must be 200v or more. The IRF9510 is only rated at 100v so it is not suitable.
Cheers
http://www.diyaudio.com/forums/showthread.php?postid=595571#post595571
A version of this amp uses the IRFP9620 in the second stage as part of a cascode. The main thing you need to worry about this FET is the Vgs which must be 200v or more. The IRF9510 is only rated at 100v so it is not suitable.
Cheers
!
Maybe this link will help...
http://217.26.67.168/uploads/9/3/937415/tecton-MK2sema.pdf
I have in mind too built this amplifier with power supply +/-75V DC,power around 300W 8ohm and 600W 4ohm.
Maybe this link will help...
http://217.26.67.168/uploads/9/3/937415/tecton-MK2sema.pdf
I have in mind too built this amplifier with power supply +/-75V DC,power around 300W 8ohm and 600W 4ohm.
Hi viktor1986
This is what I get by clicking on the link
403 Forbidden
You must supply a local referer to get URL '/uploads/9/3/937415/tecton-MK2sema.pdf' from this server.
Anything you can do about this? Tks
AndrewT
I know their specs are not close (they are not equivalent) but they may be able to swap in for this circuit (alternative). Sorry if I am confuse you.
This is what I get by clicking on the link
403 Forbidden
You must supply a local referer to get URL '/uploads/9/3/937415/tecton-MK2sema.pdf' from this server.
Anything you can do about this? Tks
AndrewT
I know their specs are not close (they are not equivalent) but they may be able to swap in for this circuit (alternative). Sorry if I am confuse you.
