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Thread: +/- 24volts for galvos

  1. #21
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    and it also seems way overpriced!! 57 euros for 2 caps, a pcb and the bridge rectifiers?? and the caps are not even audio grade

    anyway, i chose the analog way, one heavy 2x18 transformer is sitting on my desk alongside two 10.000uF capacitors and this will power the galvos only, so i'm golden

    thanks to bart and sbk for the input on that "strange railsplitter" chip
    "its called character briggs..."

  2. #22
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    Yes I believe that as usual, a big part of the price is going to the "engineering" (not really difficult though), PCB manufacturing and benefit for HB
    Anyway your transformer will work just fine. 10.000uF caps are a bit overkill but if you have enough space that can't be bad at all

    On my side I found and buyed this one, which is an audio grade SMPS and seems great quality especially for the price. Will test it as soon as I receive my EMS7000 scanners

  3. #23
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    @*^&%&*%^!!!
    Still waiting for my SMPS300R's ....

  4. #24
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    Quote Originally Posted by sbk View Post
    On my side I found and buyed this one, which is an audio grade SMPS and seems great quality especially for the price. Will test it as soon as I receive my EMS7000 scanners
    I looked at this one too but ditched it due to the lack of specific data like ripple @ rated power, rise time and such and due to it being a Chinese build.

  5. #25
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    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    I use massive unregulated linears with crowbar circuits. If something does go wrong, the crowbar kills the power to the amps in about 20 nanoseconds (no, I'm not kidding, moderate size SCRs are fast, and they short the rail till the fuse blows) This is the classic, preswitcher way to power Cambridges, and I use 2 transformers with my choice of 19 or 27 V taps, the transformers are so massive as to be self regulating, I'm no where near core saturation.

    Before you scoff, I've had to replace switchers more often then I'd like, if my projector is on switchers, TWO spare switchers travel with me. I hate them. A well designed linear will out live me.

    BTW, there are 5 amp versions of LM317, and you can add booster transistors to the LM317 or LM338, just look at the ap note. However do not forget to add the 3 reverse protection and clamping diodes when you do the boost circuits. Some people have published the boost circuits with the diodes removed, this is wrong in so many ways.

    Steve
    Last edited by mixedgas; 12-27-2011 at 05:37.

  6. #26
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    Quote Originally Posted by mixedgas View Post
    I use massive unregulated linears with crowbar circuits. If something does go wrong, the crowbar kills the power to the amps in about 20 nanoseconds (no, I'm not kidding, moderate size SCRs are fast, and they short the rail till the fuse blows) This is the classic, preswitcher way to power Cambridges, and I use 2 transformers with my choice of 19 or 27 V taps, the transformers are so massive as to be self regulating, I'm no where near core saturation.

    Before you scoff, I've had to replace switchers more often then I'd like, if my projector is on switchers, TWO spare switchers travel with me. I hate them. A well designed linear will out live me.

    BTW, there are 5 amp versions of LM317, and you can add booster transistors to the LM317 or LM338, just look at the ap note. However do not forget to add the 3 reverse protection and clamping diodes when you do the boost circuits. Some people have published the boost circuits with the diodes removed, this is wrong in so many ways.

    Steve
    That’s a good idea, since I’m going with a home built unregulated linear PSU and haven’t built them yet this will be a good feature to add to protect them EMS7000s there. The extra parts is penny shit!

    Thanks for the heads up Steve.

  7. #27
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    I believe that it's supplying 50-60 Hz half wave to each rail rather than the full wave bridge capable of 100-120 Hz requiring less filtering and smoother DC output, if I'm looking at this correctly.
    -edit- (oops-didnt see page 2 before posting this ..)
    this was in response to posts 19 and 20.. lol I need to wake up.
    Last edited by steve-o; 12-27-2011 at 06:56. Reason: getting coffee now

  8. #28
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    Quote Originally Posted by -bart- View Post
    @*^&%&*%^!!!
    Still waiting for my SMPS300R's ....
    They have been really slow with my order too, also for answering my requests. But it arrived finally so no worries...

    Quote Originally Posted by Solarfire View Post
    I looked at this one too but ditched it due to the lack of specific data like ripple @ rated power, rise time and such and due to it being a Chinese build.
    Yes no data yet, I can measure these but not before I have access to an oscilloscope at my workplace in two weeks.

    But looking at the components used, the overall quality of the board and the few tests I made, I can already tell that they are not even remotely close to lower quality computer SMPS or so Furthermore they are "audio grade" power supply (manufacturer is in fact an enthousiast member on diyaudio.com, and this is not its daytime job but an hobby, he is actually R&D engineer), thus *should* be better quality than standard SMPS.

    Have a look at the discussion about these power supplies : http://www.diyaudio.com/forums/conne...lies-smps.html

  9. #29
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    Quote Originally Posted by sbk View Post
    They have been really slow with my order too, also for answering my requests. But it arrived finally so no worries...



    Yes no data yet, I can measure these but not before I have access to an oscilloscope at my workplace in two weeks.

    But looking at the components used, the overall quality of the board and the few tests I made, I can already tell that they are not even remotely close to lower quality computer SMPS or so Furthermore they are "audio grade" power supply (manufacturer is in fact an enthousiast member on diyaudio.com, and this is not its daytime job but an hobby, he is actually R&D engineer), thus *should* be better quality than standard SMPS.

    Have a look at the discussion about these power supplies : http://www.diyaudio.com/forums/conne...lies-smps.html
    Thanks for the link, sounds like a usable alternative. Let me know how these work out. How long was shipping?

  10. #30
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    Paid on 6th November, received on 1st December.

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