I have been meaning to make one of these clocks for a while now but still haven't done it yet despite getting some VFDs from eBay and most of the other parts a while ago.. even got a couple of MAX6921s from a very kind member on this forum
Now I just need the boards, and a case, and the switches..
Question 1: I saw in another post that the transistor Q3 was changed from a 2N2907 to a MOSFET of some kind - what is the part number of the new transistor? It does not appear to be specified in the parts list (which just says P channel MOSFET)
Question 2: The Diode part numbers in the parts list and schematic are not consistent - which one is correct?
Question 3: I am trying to decide between buying a PCB or making my own (of my own design)... If I was to attempt my own PCB, are there any areas in which the layout is critical for proper operation? Note that I would be trying a single-sided board.
Ice Tube Clock: PCB layout and Q3 \ Diode Questions
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
the parts list is what is in the kit. you can use any P mosfet
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
So which MOSFET do you ship with the kit now? Just anything you have on hand?
- stinkbutt
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
http://www.ladyada.net/make/icetube/parts.html
They use a Vishay IRFD110PbF.
Dunno what a HEXFET is but I suspect it's just the brand name they use for their power FETs.
They use a Vishay IRFD110PbF.
Dunno what a HEXFET is but I suspect it's just the brand name they use for their power FETs.
- mitpatterson
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
@ stinkbutt They where talking about Q3
P-channel MOSFET Which doesn't have a link to a part number or anything RTFT
P-channel MOSFET Which doesn't have a link to a part number or anything RTFT
- mitpatterson
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
@ agent24 i just looked on my Icetube clock( about 2-3 months old) and it is the PN2907A transistor, the same as is on the picture next to Q3 on the parts list(its hard to read in the pic):
Here is a link to one at mouser:
http://www.mouser.com/ProductDetail/Cen ... P39bjOo%3d
And at Digikey:
http://search.digikey.com/scripts/DkSea ... 07ATACT-ND
Now to note the PN2907A is getting a bit hard to find at times, as i belive one of the manufacturer (either On-Semi or Fairchild, i can't remember and can't find it right now) has put it at the end of life, if you have trouble finding these in a week or what ever(they are in stock right now) let me know and i'll find the replacement, it has a direct replacement, can't recall the part number off hand
Here is a link to one at mouser:
http://www.mouser.com/ProductDetail/Cen ... P39bjOo%3d
And at Digikey:
http://search.digikey.com/scripts/DkSea ... 07ATACT-ND
Now to note the PN2907A is getting a bit hard to find at times, as i belive one of the manufacturer (either On-Semi or Fairchild, i can't remember and can't find it right now) has put it at the end of life, if you have trouble finding these in a week or what ever(they are in stock right now) let me know and i'll find the replacement, it has a direct replacement, can't recall the part number off hand
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
The v1.1 schematic I downloaded shows Q3 as a 2N2907.mitpatterson wrote:@ agent24 i just looked on my Icetube clock( about 2-3 months old) and it is the PN2907A transistor, the same as is on the picture next to Q3 on the parts list(its hard to read in the pic):
Now to note the PN2907A is getting a bit hard to find at times, as i belive one of the manufacturer (either On-Semi or Fairchild, i can't remember and can't find it right now) has put it at the end of life, if you have trouble finding these in a week or what ever(they are in stock right now) let me know and i'll find the replacement, it has a direct replacement, can't recall the part number off hand
However, I noticed in this thread: that someone had an issue with their clock, and the fix was to replace Q3 with a P-channel MOSFET.
The reply was:
His problem appeared to have been fixed by the change in Q3, but there was no mention of the new part number.adafruit wrote:oh you have an older kit. we're not shipping with a different part, email support@adafruit to get the replacement that works better
By the way, what is the replacement for the 2N2907? I would certainly like to know for future reference.
Obviously a lot of people are using the 2N2907 just fine, but then the parts list doesn't say that anymore. Is that because it's EOL?
I am just confused, should I get a 2N2907 (or the replacement) or a MOSFET?
Or do I only need the MOSFET if the clock has the issue as the other person had (I don't even know what the cause of that issue is, either)
- mitpatterson
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
its not a 2N2907, its a PN2907 I guess it was on semi that was EOLing it, it appears Fairchild has not EOL'ed it yet, but for On-semi there replacement product is MPS2907AG and here is a mouser link:
http://www.mouser.com/ProductDetail/ON- ... jLNA%3d%3d
and for reference here is On's EOL notice that show the replacement on page 5:
http://www.onsemi.com/pub/docs/pcn/PD16155.pdf
http://www.mouser.com/ProductDetail/ON- ... jLNA%3d%3d
and for reference here is On's EOL notice that show the replacement on page 5:
http://www.onsemi.com/pub/docs/pcn/PD16155.pdf
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
I said 2N2907 as that's what the schematic said. Although after some looking around it seems the 2N is the metal can TO-18 version and PN is the plastic TO-92 version.
Am I right in thinking that they are the same save for the package?
I found the replacement also at Farnell (now element14) http://nz.element14.com/on-semiconducto ... =MPS2907AG
I can't buy from Mouser\Digikey (while I would like to, you need over $200 order for free shipping, and shipping is too much when it's not free)
Am I right in thinking that they are the same save for the package?
I found the replacement also at Farnell (now element14) http://nz.element14.com/on-semiconducto ... =MPS2907AG
I can't buy from Mouser\Digikey (while I would like to, you need over $200 order for free shipping, and shipping is too much when it's not free)
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
see the parts list for the MOSFET currently used.Agent24 wrote:So which MOSFET do you ship with the kit now? Just anything you have on hand?
please note that "DIY" kits are completely unsupported, we only provide support for purchased kits, thanks!
if you enjoy our free kit designs and forum, please help us by purchasing one of our fine products
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
But the parts list does not specify any number for the "P Channel MOSFET" which is what Q3 is described as.adafruit wrote:see the parts list for the MOSFET currently used.Agent24 wrote:So which MOSFET do you ship with the kit now? Just anything you have on hand?
please note that "DIY" kits are completely unsupported, we only provide support for purchased kits, thanks!
if you enjoy our free kit designs and forum, please help us by purchasing one of our fine products
I know you said in the first reply that "You can use any P MOSFET" but I would rather use whichever one you used, then I know it will work.
As mitpatterson said, the photo shows a 2907A but that is obviously not a MOSFET.
I know you don't provide support to DIY builds and I am not asking for that (or am I?)
Just want to know the part number and if the MOSFET is an official new part or if it's only for people who have certain issues with their clocks...
I do very much appreciate the designs and the forum but I already have most of the parts, so it would be a waste of money for me to buy the complete kit. (Doesn't help that I also find it more fun to try to do things all my own way)
I may still buy the board and box yet, though, if trying to design my own board gives me too much of a headache
- opossum
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
2N4403 can usually be used in place of 2N2907/PN2907 and 2N3906.
You don't have to use the ZVP3306A MOSFET. Just cut the trace between the transistor and the AVR, and use a 470 ohm resistor to limit the base current to a safe level.
You don't have to use the ZVP3306A MOSFET. Just cut the trace between the transistor and the AVR, and use a 470 ohm resistor to limit the base current to a safe level.
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
ZVP3306A! It has a name! So this is the replacement sent to those with problems?oPossum wrote:2N4403 can usually be used in place of 2N2907/PN2907 and 2N3906.
You don't have to use the ZVP3306A MOSFET. Just cut the trace between the transistor and the AVR, and use a 470 ohm resistor to limit the base current to a safe level.
Why does this issue not affect everyone? (or does it?)
What is the issue? Q3 drawing too much current from the AVR causing damage?
For the modification, I take it the 470 ohm resistor goes between the AVR and the base of Q3?
- opossum
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Re: Ice Tube Clock: PCB layout and Q3 \ Diode Questions
It does. They all could fail.Agent24 wrote: Why does this issue not affect everyone? (or does it?)
Yes. Damage or unreliable operation.What is the issue? Q3 drawing too much current from the AVR causing damage?
Yes.For the modification, I take it the 470 ohm resistor goes between the AVR and the base of Q3?
Please be positive and constructive with your questions and comments.