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Author Topic: 8x8x8 multiplexed LED cube with an Arduino Mega 2560  (Read 35301 times)
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Also, do you think this power supply is good enough?
http://www.ebay.com/itm/5V-2A-DC-2-5mm-EU-Plug-Power-Supply-Adapter-Converter-Chager-for-Tablet-PC-/190705402077?pt=US_Server_Power_Supplies&hash=item2c66ed80dd
It doesn't say that it's regulated, I don't know if that matters or not...

It says it recognises a fully-charged battery and switches to a save mode, which is not what you want.

Or perhaps a 5V 3A power supply, might be good for future projects which need more juice:
http://www.ebay.com/itm/BRAND-NEW-5V-3A-AC-100-240V-DC-Switching-Power-Supply-Converter-Adapter-EU-Plug-/390494389454?pt=Multipurpose_AC_to_DC_Adapters&hash=item5aeb4784ce
This one says that it's a "Switching power supply"...

Switching power supplies are always regulated.

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Cluj-Napoca, Romania
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Thank you!
I'd rather not go into the SMD area for now, though smiley Keep it simple is my motto smiley
Is there some other normal MOSFET instead of the NDP6020P that I could use?
What do you think of the power supplies?

Thanks!
Andras
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 Here is the mosfet that I used with the 3x3x3 and I think it big enough for my 5x5x5.  It is a ZVP2106A

http://www.diodes.com/datasheets/ZVP2106A.pdf
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@Un4seen,
I selected the MOSFET I did because it was the lowest priced thru hole part at Digikey with low Rds.
I don't search on e-bay as I find it a waste of time trying to search by characteristic.

Update your profile to show a country, lets see what you have for parameter searchable sources.
« Last Edit: December 29, 2012, 11:12:53 am by CrossRoads » Logged

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 Here is the mosfet that I used with the 3x3x3 and I think it big enough for my 5x5x5.  It is a ZVP2106A

http://www.diodes.com/datasheets/ZVP2106A.pdf

The OP's schematic indicates that he needs to switch 1.28A, which implies that in order to keep the voltage drop and power dissipation low, the Rds(on) needs to be low. I suggest a maximum Rds(on) of 0.1 ohm, and that is what I looked for when I searched for suitable mosfets. The part you linked to is designed for 10V gate drive and even then it has Rds(on) of 5 ohms. So it isn't really suitable for this application.

I suggest either the mosfet that Crossroads selected, or the SMD part I linked to along with some SOT23 to DIP adapters such as these http://www.ebay.co.uk/itm/10pcs-SOT23-Dip6-Adapter-PCB-SOT-23-6-/360441877952?pt=LH_DefaultDomain_0&hash=item53ec0295c0.
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Wow,  10 pieces for $7.50  - that adds a lot to cost of the MOSFET!
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Hi guys!

I've updated my profile to show my location, sorry about not showing it before.

I live in Romania, so have 3 options:
1. Buy from local stores, which have very high prices. For the NDP6020P-ND it's not an option at all, they don't sell it here and they can't even place an order to bring it from an international supplier.
2. Buy from eBay. It's cheap and usually there are plenty of items and sellers to choose from, but delivery takes a month.
3. Order from UK online stores which ship internationally. I've never done it so far because the cost of transport was ridiculously high when I looked for some items in the past.

Every time I try to solder together some circuit, I reach the same conclusion: I should move to UK smiley-razz
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Wow,  10 pieces for $7.50  - that adds a lot to cost of the MOSFET!

Unfortunately, yes - although SMD mosfets are so cheap that it still costs less than using a TO220 mosfet (but a lot more work of course).

One day I'll get round to sending an SMD adapter design off to Itead to reduce the cost. It would be useful to have boards that take 2 or 4 SOT23 devices too.
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I live in Romania, so have 3 options:

Have you tried http://ro.farnell.com/?
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Is Farnell expensive in Romania?
For a part like this?
I don't know what this price relates to in US dollars.
http://ro.farnell.com/international-rectifier/auirf4905/mosfet-w-diode-p-ch-55v-74a-to220ab/dp/1865604
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I bought a sheet of adapters like
http://www.ebay.com/itm/SMD-CONVERTER-ADAPTER-PCB-SOT-TO-MSOP-SIP-DIP-14-/270832318388?pt=LH_DefaultDomain_0&hash=item3f0edd37b4
Probably had like 20 each of the different adapters on it.
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I have just tried Farnell. They sell it for about 2.5$, same as the Chinese eBay seller (which could be fake). They say it's coming from UK, so it would probably take less time. The problem is however, that they haven't got a user-friendly site and I just can't figure out how much the transport to Romania would be without trying to actually buy the stuff smiley
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Is Farnell expensive in Romania?
For a part like this?
I don't know what this price relates to in US dollars.
http://ro.farnell.com/international-rectifier/auirf4905/mosfet-w-diode-p-ch-55v-74a-to220ab/dp/1865604

They sell the one you originally suggested for less, see http://ro.farnell.com/fairchild-semiconductor/ndp6020p/mosfet-p-to-220/dp/1017724?Ntt=NDP6020P-ND.

PS - 7.06 RON = 2.10066 USD according to xe.com
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I have just tried Farnell. They sell it for about 2.5$, same as the Chinese eBay seller (which could be fake). They say it's coming from UK, so it would probably take less time. The problem is however, that they haven't got a user-friendly site and I just can't figure out how much the transport to Romania would be without trying to actually buy the stuff smiley

If you go through the order placement process, I think you will find the carriage cost (if any) added on before you get asked for your credit card details. It may be free, some of the stuff I buy from Farnell gets shipped form mainland Europe and I don't get charged extra. You may find there is a minimum order, it's GBP20 here in the UK for non-business accounts.
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OK, I have figured it out smiley As I wrote, one NDP6020P costs about 2.5$ at Farnell. The transport to Romania would be 5 Euro, regardless of what is in the package. So, assuming that I'd buy 15 pieces of NDP6020P (8 for the 8x8x8 cube, 5 for the 5x5x5 cube and 2 for spares), the total cost would be around 27E or 35$. That's more than the 1000 LEDs and about 33% of the total project cost smiley I there's no other choice, I'll go for it, but if there's some more widely available, less expensive MOSFET, I'd prefer that smiley
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