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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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17th Aug 2016, 12:11 pm | #1 |
Heptode
Join Date: Aug 2004
Location: Woodbridge, Suffolk, UK.
Posts: 501
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IC polarity
I feel stupid asking, but I am struggling to get a fluorescent power meter to work on a amplifier.
Pin 1 is the one on the left? Pin 1 is the one marked on the board? I have power to the IC. Signal to the IC. However voltage at power pin is full VCC, 45v, its dropped via a 1.8K which is fine. It seems the IC isn't drawing any current to drop the voltage. This is the second IC. Just making sure it is in correctly. Thanks |
17th Aug 2016, 12:17 pm | #2 |
Heptode
Join Date: Jul 2008
Location: Selby, North Yorkshire, UK.
Posts: 979
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Re: IC polarity
Usually pin 1 is marked by a dot or a missing corner. So yes - I would assume that pin 1 is the one on the left in your photo.
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17th Aug 2016, 12:28 pm | #3 |
Rest in Peace
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
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Re: IC polarity
DIL ICs, such as that one,have pin 1 to the front LH side when viewed from above. As richrussell says, there is usually an ident such as a dot close to pin1, or often a small notch between the two end pins at the pin 1 end.
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17th Aug 2016, 12:48 pm | #4 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,527
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Re: IC polarity
But that looks like a SIL IC......
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17th Aug 2016, 12:50 pm | #5 |
Banned
Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
Posts: 3,897
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Re: IC polarity
So it does, in which case pin one is the left hand end, with the corner clipped. Duff batch or counterfeit chips?
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17th Aug 2016, 12:51 pm | #6 |
Heptode
Join Date: Mar 2016
Location: Essex, UK.
Posts: 602
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Re: IC polarity
This might help.
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17th Aug 2016, 12:52 pm | #7 |
Octode
Join Date: Feb 2006
Location: Bristol, UK.
Posts: 1,030
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Re: IC polarity
Reading the number as TA7318. AllDatasheet.com gives this PDF
http://www.alldatasheet.com/datashee...A/TA7318P.html Malcolm |
17th Aug 2016, 12:59 pm | #8 |
Heptode
Join Date: Aug 2004
Location: Woodbridge, Suffolk, UK.
Posts: 501
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Re: IC polarity
Hya thanks all, yes it's a sil. I did look at the data sheet too, but thought maybe i was missing something.
Just wanted to make sure I hadn't woken up a bit more barking mad. Thanks |
17th Aug 2016, 1:38 pm | #9 |
Heptode
Join Date: May 2015
Location: Bradford, West Yorkshire, UK.
Posts: 510
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Re: IC polarity
I see pin 1 as ground and pin 9 as Vcc
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17th Aug 2016, 4:50 pm | #10 | |
Guest
Posts: n/a
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Re: IC polarity
Quote:
Last edited by Guest; 17th Aug 2016 at 4:52 pm. Reason: Using works keyboard for ages, different spacing from the laptop, this edit explanation took ages to get right too! |
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