584,841 active members*
4,608 visitors online*
Register for free
Login
IndustryArena Forum > OpenSource CNC Design Center > Open Source Controller Boards > Open Source Boards Available, Stepper Drivers and Break Out Boards
Page 23 of 39 13212223242533
Results 441 to 460 of 763
  1. #441
    Join Date
    Aug 2004
    Posts
    170
    Phil:
    I saw your Optp-isolators. They have much "legs" to me, why not try the 4N25 ones? Just 6 legs (4 useables) ! I think it´s possible on one sided...

  2. #442
    Join Date
    Jun 2003
    Posts
    3312
    4N25's might work, but the problem I have is the might portion. There are some spec issues that concern me driving straight from a parallel port.

    Phil

  3. #443
    Join Date
    May 2004
    Posts
    13

    Transistor Subs for Chopper Adapter

    Hi evreryone, sorry to barge in on this thread, but I would like to build tachus42's Chopper Adapter and am having trouble getting a hold of the small signal transistors. I was wondering if anyone could help me with a substitution?

    I need a substitute for the PNP trnsistor: BC556
    and for the NPN transistor: BC546B

    Also, I think that the 10V zener (D6) should be at least 1W type.

    Lastly, theIRF9540 costs $4 each ($CDN). Could I substiture a IRF 9530 (only $1.50 each). I think the main diff between the two is that the 9530 canonly do 12Amp, while the 9540 can do 23Amp. I don't plan on anything more than 3amp motors at most.

    Thanks in advance for any help.

  4. #444
    Join Date
    Jun 2003
    Posts
    3312
    Heyarnold,
    This thread is open to all who have questions or want to use the boards. Off the top I don't see anything that would be an issue with th 9530. Subs for the BC series, you might look through past postings, seems like this came up before. Tachus43 really should answer that one.

    Phil

  5. #445
    Join Date
    May 2004
    Posts
    13

    Transistor Subs for Chopper Adapter

    Hi Phil,

    Thanks for you reply, you were right. I did find the post with the BC transistor subs. I pasted it below for reference. I think that I will build the chopper board with 2N3904 and 2N3906 transistors and use the IRF9530 FET as well. I have these in stock!

    My plan is to use the chopper with the kitsrus stepper kit #179, which uses the IRFZ44 FETs to drive the motor. I have had this kit for a long time and it works well. I think it will be all right with the chopper board.

    Thanks for you help!


    Posted by: tachus42 on 08-29-2004, 11:16 AM

    The transistors are not critical, most small signal transistors in a

    to-92 should be ok.Just check the pinout on the datasheet. For the

    NPN BC546,547,548,549 A,B or C will all work. Like wise for the PNP

    556,557,558,559 are ok. NPN 2n3904 PNP 2n3906 would be another

    choice.

    Oh and i don't think the power rating of the Zener was specified on

    the schematic. It should be 1 Watt.

  6. #446
    Join Date
    Apr 2004
    Posts
    169
    heyarnold the 9530 will be fine, but due to it's higher on resistance compared to the 9540 it will get a bit hotter and will probably require a small heatsink.
    The kits r us board is very similar to the "open source" design and should work fine with the chopper.

  7. #447
    Join Date
    Apr 2004
    Posts
    169
    I haven't looked at the spec sheet for the 4n25 lately but it is a pretty slow device. It is for instance useless as a isolater transmitting Midi data at 19200 baud - I tried that and failed!
    So I think apart from the current transfer ratio it would be to slow for a Bob.

  8. #448
    Join Date
    Jun 2003
    Posts
    3312
    tachus42,
    Yes the 4n25's are slow, that was one of my issues. They get slower as you reduced the led current. I believe 6n138's are a better choice. Know of any others? There used to be some dual channel hpcl's in an 8 pin pack, but I can't find a source to purchase.

    Phil

  9. #449
    Join Date
    Oct 2004
    Posts
    21
    Look another gecko look alike... has anyone seen these?
    http://www.linengineering.com/our_products/r701.htm

  10. #450
    Join Date
    Jun 2003
    Posts
    3312
    Kinda looks that way, wonder what they cost.

    Phil

  11. #451
    Join Date
    Apr 2004
    Posts
    169
    Phil was it you or someone else who posted that they thought the need for opto's was over blown? Apart from possibly solving some noise issues it would seem the biggest danger to the PC port is ground currents. With the 10k filter resistor and 1k pullup and assuming the parallel port is ok with 5mA of sink/source above and below it's supply (safe for all logic family's I have seen) either 50 volts would some how have to appear on the hc14 input or the logic supply would have to go to +10 or -5 volts for there to be a problem - both of which seem to be unlikey.
    Some zeners, series resistors and a fused earth line should provide pretty good protection for the pc.

  12. #452
    Join Date
    Oct 2004
    Posts
    21
    OKay. The skinny on this is that they are made by gecko for Lin Engineering. I didn't inquire about the cost.

  13. #453
    Join Date
    Jun 2003
    Posts
    3312
    tachus42,
    I have made comments along those lines. As long as the grounding is treated appropriately, there really shouldn't be an issue in not having opto isolators. I suspect that people that have had problems, have their control electronics power supply floating and no reference back to the pc's parallel port gnd lines.

    Phil

  14. #454
    Join Date
    Aug 2004
    Posts
    170
    Ok i agree that we don´t need Optos, but it is a really good stuff. When everything fails, your PC still has a LPT...
    A friend, Maarten send me mail about optos, there it is:
    Indeed there are other optocouplers (~isolators) that are faster.
    The ton of the 4N25 is 5us, the toff is even 10us. This means that you need 5us to reach a full ON (= "1") and 10us to switch it off again. so the maximum frequency is much less than 66kHz (1/(10+5)us = 66,67kHz; and you need time for the pulse itself; the "1"or "0")

    There are faster ones like the 6N138 or CNX62 (3 / 3us) or PC816 (Sharp; 4 / 4).
    Also TIL111 and TIL112 (resp. 5/5 and 2/2 ) are pretty fast. But the Uce Umacx of the TIL112 is pretty low 20V.
    And the Current Transfer Ratio is low (TIL12 (atleast) 2%).
    Toshiba has a few super fast ones, like TLP 555 (<=0.4 / <=0.4us; U<=20V)

    So every part has its advantages and disadvantages...
    Maybe its best to try what best suits your needs.
    BR, Maarten.

  15. #455
    Join Date
    Jun 2003
    Posts
    3312
    Interesting,
    Maybe I looked at a 4n45, because I was thinking much slower which the 4n25 is. e. I'll look at it some more.

    Phil

  16. #456
    Join Date
    Jul 2003
    Posts
    45
    I am in the process of building my second machine, Jgro's plans only a little smaller. I was looking at the circuits and wondered which set up would be the best to use. I will be using 2A steppers.
    I could manufacture all of them, I am an electronics engineer (but not motor drivers!) and use a bungard cnc mill at work. The last circuits I used were hans wedermiers (?) 297/298 circuits which worked well although a bit noisy. What are the advantages/disadvantages of the circuits? and are the Eagle files available?

    Thanks Paul

  17. #457
    Join Date
    Jun 2003
    Posts
    3312
    Eagle files are available. Unipolar or bipolar?

    Phil

  18. #458
    Join Date
    Jul 2003
    Posts
    45
    all my motors are unipolar
    Paul

    sorry, just checked my original 3 are unipolar my spare 3 are bipolar but I can swap and change
    Paul (chair)

  19. #459
    Join Date
    Jun 2003
    Posts
    3312
    How did you run a unipokar with the L297/8 combo?

  20. #460
    Join Date
    Jul 2003
    Posts
    45
    I left the common centertaps unconnected
    Paul

Page 23 of 39 13212223242533

Similar Threads

  1. Best break out boards?
    By Nigel Tufnel in forum Stepper Motors / Drives
    Replies: 2
    Last Post: 12-27-2013, 07:12 PM
  2. Dual Break out boards
    By ynnek in forum DIY CNC Router Table Machines
    Replies: 1
    Last Post: 07-11-2013, 04:34 PM
  3. Break out boards...
    By kiwichris in forum LinuxCNC (formerly EMC2)
    Replies: 12
    Last Post: 11-06-2012, 10:20 PM
  4. Servos, drivers, break out boards
    By HereinCS in forum Servo Motors / Drives
    Replies: 1
    Last Post: 08-13-2010, 06:09 PM
  5. PC parallel port break-out boards
    By widgitmaster in forum CNC Machine Related Electronics
    Replies: 4
    Last Post: 09-20-2005, 01:47 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •