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RECOM pin compatible DC-DC 7805 regulator replacements

guesserguesser
edited August 2012 in Hardware
Finally got myself sorted out now. If you want to purchase chips send me an email to alistair@alistairsserver.no-ip.org with your paypal details and how many chips you want.

The final price is ?6 each plus postage.

I've replaced the regulator in my spectrum+ with one and it runs nicely, with a spectranet connected too :)
They really do run completely cold. You can put your finger on it and it's not even warm :-o
Post edited by guesser on
My rubbish website including the redrawn Amstrad schematics and the Sinclair Wiki.

Comments

  • MobutuMobutu
    edited July 2011
    What difference has with Tracopower Tsr-1 2450?
    Thanks!!
  • guesserguesser
    edited July 2011
    Mobutu wrote: »
    What difference has with Tracopower Tsr-1 2450?
    Thanks!!

    Looks more or less identical to that device.
    Datasheet here http://www.recom-international.com/pdf/Innoline/R-78xx-1.0.pdf
    My rubbish website including the redrawn Amstrad schematics and the Sinclair Wiki.
  • BloodBazBloodBaz
    edited September 2011
    Hi,

    I'm finding that running my Rubber 48K Spectrums with DivIDE Plus is suffering from heating problems that cause the "K" key (close to internal heatsink) pressing when I press keys near it. The heat can be annoying on the hand too.

    Is this regulator okay for 48K Spectrums with additional interfaces such as DivIDE?
    Do you still have some available or can you tell me where I can buy 2-3?
    Are they easy to solder out/in (and can you really run it without a heatsink?)

    Finally, do you think I should I use a modern regulated PSU or the traditional speccy ones with these regulators?

    Sorry to load you with questions!?

    Cheers, BloodBaz
  • guesserguesser
    edited September 2011
    BloodBaz wrote: »
    Is this regulator okay for 48K Spectrums with additional interfaces such as DivIDE?
    Do you still have some available or can you tell me where I can buy 2-3?
    Are they easy to solder out/in (and can you really run it without a heatsink?)

    Finally, do you think I should I use a modern regulated PSU or the traditional speccy ones with these regulators?

    Hi BloodBaz. Some answers in no particular order:

    Yes I have plenty left, send me an email alistair@alistairsserver.no-ip.org
    The 48k+ on the desk in front of me has one of these regulators and runs happily with a spectranet attached which I suspect requires more power than the divide. I run it from a normal 48k PSU, the RECOM chip works with a power supply voltage anywhere between 6.5 and 18 volts so a regulated PSU isn't necessary.

    The device is as easy/hard to solder as a normal 7805, rather depends on your skill level :)
    The RECOM chip stands upright rather than having the leads bent and the regulator flat with the board as the 7805 would.
    It really doesn't need a heatsink and there is in fact no way to affix one! You can rest your finger on the chip while the 48k and addons are running, something that would leave you with a blister if you tried it with a 7805 :)
    My rubbish website including the redrawn Amstrad schematics and the Sinclair Wiki.
  • BloodBazBloodBaz
    edited September 2011
    Cheers guesser. I have emailed you an order.
    Will be nice having a cool spectrum or two! :grin: :grin: :grin:
  • spiderspider
    edited February 2012
    Are these still available ? :)

    I don't like the way mine heats up so this would be ideal (although it is better since I noticed the bolt was a bit loose) but yes would rather have this replacement instead.
    Please visit the JetSet Willy & Manic Miner Community
  • MaccMacc
    edited February 2012
    Just like to add that I ordered two off guesser and now my speccy runs super cool!
  • guesserguesser
    edited February 2012
    spider wrote: »
    Are these still available ? :)

    I don't like the way mine heats up so this would be ideal (although it is better since I noticed the bolt was a bit loose) but yes would rather have this replacement instead.

    Yep. Drop me an email alistair@alistairsserver.no-ip.org :smile:
    My rubbish website including the redrawn Amstrad schematics and the Sinclair Wiki.
  • pkerseypkersey
    edited August 2012
    Hi, Guesser. I have read the datasheet but the output current is only 1A. Is that right? Will this work on a +2/+3?

    Is the correct component specification R-785.0-1.0?

    Thanks.
  • guesserguesser
    edited August 2012
    The 128k and Grey +2 require a higher current, these are only suitable for the 48k machines. There are RECOM chips with higher rated outputs but I only have the 1A ones.

    The +2A/+3 have no voltage regulator at all
    My rubbish website including the redrawn Amstrad schematics and the Sinclair Wiki.
  • georgedbgeorgedb
    edited August 2012
    http://www.elektor.com/subs/coming-attractions.79089.lynkx
  • KnikKnik
    edited August 2012
    I,m using a 1.5 A Recom in a spectrum +2.
    Works very nicely.
    I reccommend them if you want a cooler system.
  • ingoingo
    edited August 2012
    I use this one http://www.ebay.co.uk/itm/270900301106 in my harlequin and in future also in my 128 k heatsink. It is reliable, cheap and small.

    Greets Ingo.
  • 1024MAK1024MAK
    edited August 2012
    There do seem to be a number of these LM2596 DC-DC step down converters on eBay

    Mark
    Sinclair FAQ Wiki
    Repair Guides. Spanish Hardware site.
    WoS - can't download? Info here...
    former Meulie Spectrum Archive but no longer available :-(
    Spectranet: the TNFS directory thread

    ! Standby alert !
    “There are four lights!”
    Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
    Looking forward to summer in Somerset later in the year :)
  • pmsrpmsr
    edited August 2012
    1024MAK wrote: »
    There do seem to be a number of these LM2596 DC-DC step down converters on eBay

    Mark

    1.06? with free shipping from China? Can that be any good?

    /Pedro
  • 1024MAK1024MAK
    edited August 2012
    pmsr wrote: »
    1.06? with free shipping from China? Can that be any good?

    /Pedro
    Well, looking at the pictures, there are a number of variations in the components used.
    The one that Ingo pointed two (also available from at least one other seller) uses three electrolytic capacitors in total, plus what looks like an extra inductor (choke) to reduce the high frequency ripple.

    Some of the boards appear to be the minimum basic circuit (like the one you are referring to).

    Some appear to have a input protection diode (to prevent damage when accidentally connected with an incorrect input polarity).

    Some have input electrolytic capacitors rated at 50V (so the max input is quoted as 40V), while some have input electrolytic capacitors rated at 35V (so max input is 35V if you dare...).

    It would help if all sellers published the performacne specifications / characteristics :evil:

    I have ordered one like that pointed to by Ingo but from a different seller (item number: 330650881112 from dailydealuk) plus two other cheep ones to see what they are like.

    In any case, they all need the person fitting them to have a good multimeter (volt meter) to set the output voltage correctly.

    Mark
    Sinclair FAQ Wiki
    Repair Guides. Spanish Hardware site.
    WoS - can't download? Info here...
    former Meulie Spectrum Archive but no longer available :-(
    Spectranet: the TNFS directory thread

    ! Standby alert !
    “There are four lights!”
    Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb!
    Looking forward to summer in Somerset later in the year :)
  • ingoingo
    edited August 2012
    1024MAK wrote: »
    In any case, they all need the person fitting them to have a good multimeter (volt meter) to set the output voltage correctly.
    Yes, and a calm and competent hand is needed, because it is very sensible to set. I plan to remove the trimmer and to use fixed value resistors to avoid any trouble. Additionally I recommend to add a suppressor diode BZW06/5.8 http://www.pr-tronik.de/fileadmin/pdf/bzw06.pdf parallel to the 5V line of the spectrum (output of switching regulator) to safe the circuitry against spikes and malfunction of the switching regulator. This diode is able to take up to 100 A if the voltage exceeds 6.8V. It can consume momentary 600W. The circuitry of my MB02+IDE has such diode and my spectrums will be saved also by such suppressor diode.

    Greets Ingo.
  • RetroTechieRetroTechie
    edited August 2012
    pmsr wrote: »
    1.06? with free shipping from China? Can that be any good?
    LM2596 is already more than that, directly from manufacturer in 1K+ quantities. Maybe these are Chinese clone parts, or a batch of them was dumped somewhere (backdoor from same factory, non-RoHS compliant, whatever). But then there's still the board, caps, coil + shipping. So I don't see how they can possibly make a profit at that price. :-?

    Probably it's just a way to lure you into their eBay store, counting on the average shopper to order more than that DC-DC converter.
  • KnikKnik
    edited August 2012
    Eqiupment directly from Asia ( manufacturer ) is cheaper, because there are no middlemen.
    And the components are often manufactured in Asia, therefore also much cheaper than they are here.
    The labour is often much cheaper also...
  • orangeorange
    edited April 2021
    are there any more options like this? both 'RECOM R-785' and 'Tracopower Tsr-1 2450' are hard to find here.

    edit:
    found these two:
    TPSM84205EAB
    MP-K7805-1000R3

    second one is quite cheap compared to others.
    are they any good?
    Post edited by orange on
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