Q13 is a BC550 correctly oriented. It is interesting that both channels behave the same. What is a surefire way to determine if the latfets are authentic? Any in-circuit measurements? I have additional if they need to be tested out of circuit. The power supply is +-40VDC, if that matters. Thanks!!!
k1058/j162 text is printed in light gray color. If its white and bright, then you got dummies for sure. also the original latfets that I have look old / not shiny finish.
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Double check for correct Q5 and Q8 pin orientation if you replace with bc550/560. They have different pin assignment to bc639/640.
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See which make you have
http://www.nxp.com/documents/data_sheet/BC549_550.pdf
http://www.onsemi.com/pub_link/Collateral/BC549B-D.PDF
they both have different pin orientation NXP is EBC and onsemi and others are CBE😀
reg
Prasi
no they have not.... first datasheet is bottom view and pin-numbering is different
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I always measure transistors before stuffing.
There are e.g. BC560 with different pinout
http://cdn-reichelt.de/documents/datenblatt/A100/BC559B_BC559C_BC560B_BC560C-CDIL.pdf
There are e.g. BC560 with different pinout
http://cdn-reichelt.de/documents/datenblatt/A100/BC559B_BC559C_BC560B_BC560C-CDIL.pdf
such confusion... 1 in one becomes a 3 in other... why don't these manufacturers use a universal notation and make a diyer's life easy. never used NXP myself.
CDIL should be hung, drawn and quartered for changing the BC5xx to that non standard pin out.
It could be that CDIL make hundreds of other EBC pin out To92 and can't be bothered to make a jig to put the BC5xx pins in the correct positions (CBE) ready to be moulded.
Shame on CDIL.
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I too ALWAYS check the pin out & sex of a transistor BEFORE assembly.
I also happen to record the hFE (DMM approx value) on the sch for future reference.
the fun part is that CDIL also seem to make BC560 with the usual pinout
BC560 PDF Datasheet - Continental Device India Limited (CDIL) - Datasheets360.com
It's just that Reichelt sold me the odd ones. So while you are at it, please HDQ them, too 😀
BC639 / BC640 in those positions. Only sub was 550 for 547 and 560 for 557. Thanks!!!
@ marsupialx
Measure P1 value in circuit without power, try both ways with meter leads, read both values. With power, confirm ~0.67V Vbe and measure Vce of Q13.
Most probable is either Q13 is somehow not forward biased properly or faulty P1.
Measure P1 value in circuit without power, try both ways with meter leads, read both values. With power, confirm ~0.67V Vbe and measure Vce of Q13.
Most probable is either Q13 is somehow not forward biased properly or faulty P1.
Hi all,
Here are the files for DIY for anyone willing to try. Rest assured, sch and layout are compatible. If anyone finds a problem, do let me know for correction.🙂
reg
Prasi
Here are the files for DIY for anyone willing to try. Rest assured, sch and layout are compatible. If anyone finds a problem, do let me know for correction.🙂
reg
Prasi
No comments still from designer. OK..., if anyone builds pl share your review here , I am interested to know.
reg
Prasi
Sorry prasi, I wasn't aware that you expect a comment from me.
Of course, everyone is free to make his own layout and tries to improve the one I published but please don't expect me to supervise all you guys do.
Have fun !
Of course, everyone is free to make his own layout and tries to improve the one I published but please don't expect me to supervise all you guys do.
Have fun !
I thought I said that in post #131. anyways, I have done my part here as per the request of a member.
thanks and regards
Prasi
P.S. almost defeats the ["forum"- "designer-thread starter"] concept for the benefit of others.
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Layout Software.
Hi Prasi,
Did you use Sprint-Layout or some other software for your layout?
Thanks...
Hi Prasi,
Did you use Sprint-Layout or some other software for your layout?
Thanks...