...
Tomorrow I will fire up the amp's PSUs for the first time and then couple them up on the bench.
Congratulations! Nice test setup! Your heat spreader designed for MODU case series "Pesante Dissipante" looks very good!
BR, Toni
Nice and compact design!... more SMD parts ...
... prototype board ready for programming...
Have fun, Toni
can u help me to add ne5532 to ltspice model please.
thank you
Your question is a bit out of topic ...
- Extract attached zip file.
- Copy "NE5532.asy" to your LTSpice symbol directory (e.g. c:\Program Files\LTC\LTspiceIV\lib\sym\Opamps)
- Start recent version of LTSpice and load the attached asc file "ne5532_opamp_sim.asc".
- Run simulation
How to add your own symbols/models: Adding a permanent component to LTspice - LTwiki-Wiki for LTspice
More libraries can be found at LTspiceIV-library Library Listing Expanded - LTwiki-Wiki for LTspice
BR, Toni
Attachments
Nice and compact design!
Thanks!
New "mains inrush control" pcb: I2C library ported to pic16f1829.
Prototype is working:
- able to detect and feed data to LCD display
- able to detect and read up to 8 additional LM75 temperature sensors
- WIP for MCP23008 and MCP23016 port expanders
Attachments
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Thanks!Very cool!
Hi Toni,
I have a "what-if" question regarding your MT2015-50W. I have seen you are running ~28VAC transformer and you have measured ~80W in 8 ohm. How much will I violate SOA I change the transformer to 33VAC?
Thanks,
Mogens
Dear Mogens,
it should be SOA save to use this transformer. This would give a maximum of +/-52V DC supply (33*1,41 + 10%).
I will drive my SA2015 4 channel amp with +/-45V DC (~ max. 50VDC).
BR, Toni
Hi Toni,
Thanks. Also, in post #1422 there is a picture where the back of the mosfets can be seen. What is the meaning of what is written on the mosfets? mA at fixed Vgs? What is your experience with matching of Mosfets from the same tube?
Sorry for all the questions.
Thanks,
Mogens
Thanks. Also, in post #1422 there is a picture where the back of the mosfets can be seen. What is the meaning of what is written on the mosfets? mA at fixed Vgs? What is your experience with matching of Mosfets from the same tube?
Sorry for all the questions.
Thanks,
Mogens
...
What is the meaning of what is written on the mosfets? mA at fixed Vgs? What is your experience with matching of Mosfets from the same tube?
...
Dear Mogens,
the numbers are the order in which they appeared out from the tubes...
As you can see, there are big distances between numbers so even from the same tube/lot you can expect big variations.
E.g. I have bought > 150 pieces each to get enough good matched devices out from. Here an example of one tube of IRFP240:
Code:
# Vgs_low V Vgs_high V
001 3.440 3.926
002 3.442 3.928
003 3.436 3.925
004 3.442 3.932
005 3.448 3.938
006 3.458 3.949
007 3.460 3.953
008 3.464 3.957
009 3.465 3.959
010 3.476 3.970
011 3.333 3.819
012 3.324 3.808
013 3.317 3.803
014 3.367 3.849
015 3.362 3.846
016 3.359 3.844
017 3.347 3.831
018 3.344 3.829
019 3.359 3.845
020 3.366 3.854
021 3.372 3.859
022 3.378 3.862
023 3.380 3.863
024 3.371 3.856
025 3.369 3.855
Code:
# Vgs_low V Vgs_high V
013 3.317 3.803
012 3.324 3.808
011 3.333 3.819
018 3.344 3.829
017 3.347 3.831
016 3.359 3.844
019 3.359 3.845
015 3.362 3.846
014 3.367 3.849
020 3.366 3.854
025 3.369 3.855
024 3.371 3.856
021 3.372 3.859
022 3.378 3.862
023 3.380 3.863
003 3.436 3.925
001 3.440 3.926
002 3.442 3.928
004 3.442 3.932
005 3.448 3.938
006 3.458 3.949
007 3.460 3.953
008 3.464 3.957
009 3.465 3.959
010 3.476 3.970
P-Channel MOSFETs (IRFP9240) are even worse.
You may need to buy 2 to 4 times more IRFs as you need for your project.
BR, Toni
...
TME seems to have them at a reasonably price.
...
Fortunately IRFP240 and IRFP9240 are really cheap compared to classical audio power transistors. Hopefully they will be available for a long time ...
Hi Toni,
Do you know if the Vishay P-channel has the same transconductance anomaly as the IRF P-channel type? I think I read a comment by Bob Cordell that the Vishay type didn't have it. But, I have not seen any tests confirming this.
Mogens
Use different source resistors value for P type, one example is here. http://www.diyaudio.com/forums/solid-state/243481-200w-mosfet-cfa-amp-92.html#post4580555
I bought IRFs from TME and they are quite good matched if from the same batch.
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