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Old 18th January 2012, 10:07 PM   #511
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Quote:
Originally Posted by danielwritesbac View Post
BD139-8
How? Which datasheet specified the Ccb value of BD139?
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Old 18th January 2012, 11:25 PM   #512
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Quote:
Originally Posted by terranigma View Post
How? Which datasheet specified the Ccb value of BD139?
For BD139/BD140, its either Philips or grotesque.
Edit:
This problem is very misleading for post #1 and for post #504. At post #504, I had "best effort" for balanced parameters, as for sturdy parts doing what they should, but "inexpensive" is misleading since that schematic has an expensive collector's item for drivers. Sorry about that! I'll try to work up something else. I'm a newbie to discrete parts, so it takes a while. . .

Last edited by danielwritesbac; 18th January 2012 at 11:35 PM.
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Old 19th January 2012, 08:22 AM   #513
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@odysseybmx414
Did you ever try 2sd699a for Q5/Q6?
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Old 19th January 2012, 01:14 PM   #514
Elvee is offline Elvee  Belgium
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Quote:
Originally Posted by danielwritesbac View Post
Maybe also. . .
6pF for NXP BCP56, granddaughter of Philips BC639/BD139.
http://www.nxp.com/documents/data_sh...X56_BC56PA.pdf
Is this long awaited answer to a "currently produced" high performance part for Q5, Q6? .
Looks like a good candidate. At high supply voltages, care must be taken to provide sufficient PCB area for cooling (Pd=0.013*Vs)



[QUOTEP.S.
Derating, well, let's see if I got the concept:
Voltage, subtract about 16v from max tolerance or is there a rule of thumb percentage to use?
Output power, multiply datasheet brag by 0.75, like 200w output device x 0.75 = 150w useful?][/QUOTE]
Things are a bit more complicated than that.
You can find informations on this forum and on other specialized websites, like ESP.
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♫♪ My little cheap Circlophone© ♫♪
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Old 20th January 2012, 05:52 AM   #515
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Default Credit card sized Circlophone?

Well, I think I've made some progress with the layout, but I'd love to know if you see any errors except for slightly incomplete. . .
Attached Images
File Type: jpg CirclophonePhenolic.jpg (327.1 KB, 3664 views)
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Old 20th January 2012, 07:57 AM   #516
Elvee is offline Elvee  Belgium
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Looks promising, do not forget to place the bypass capacitors to the right of the board
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Old 20th January 2012, 10:29 AM   #517
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It seems Philips BD139 has 6pF level Cob which gets along with never BCP56's. Bad thing is i could only find Philips BD137's. They are at very edge with my 30V supplies.

BD139-16 & BD140-16? Anyone use these transistors?
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Old 20th January 2012, 06:38 PM   #518
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There's several pairs to use for 4 to 16pF:
2sd699a, 2sb649
NXP BCP56, BD140
2sa1358, 2sc3421
2sa1930, 2sc5171

I find it interesting that the good drivers also have complimentary partners that could work for phase inverter. In addition to new production NXP BCP56, you also have the ever expanding list of NOS Motorola that, if given a big enough list, can make it possible to shop for them. I'm currently researching to126 and to220 subs, since the larger casing has some heat sink related convenience. There's many listed, but the question is which are available, so that takes a while to research.
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Old 20th January 2012, 07:24 PM   #519
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I ordered 50pcs Philips BCX56's for good price. I will solder their collector plate to a suitable copper heatsink.

Philips NPN 80V/1A Transistor BCX56-10, SOT-89, 50pcs | eBay
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Old 21st January 2012, 12:13 AM   #520
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I did that once with some resistor packs. Dummy load...
soldered several to a big, skived, solid copper heatsink.

Easiest is with paste solder, and put the whole thing
in a reflow oven. Else the heatsink itself fights you.

Might be doable with a heatgun, if you can direct the
blast into the fins.
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