Results 1 to 20 of 20

Thread: Question on a power supply

  1. #1
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11

    Question on a power supply

    Have a power supply out of a electric piano

    My question is for the 5 volt regulator having 2 inputs
    I want to cobble a transformer to power this circuit, being that it has a 5 volt regulator, just not sure about pins1 2 3Click image for larger version. 

Name:	kurzweil.jpg 
Views:	37 
Size:	87.8 KB 
ID:	54295
    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  2. #2
    Senior Member
    Join Date
    May 2006
    Location
    Cheshire, UK
    Posts
    2,104
    Thumbs Up/Down
    Received: 417/4
    Given: 241/0
    Rep Power
    16
    It's a full wave rectifier. It needs a centre tapped transformer winding. Something like 7-0-7 volts should do it (as the input capacitors look to be only rated at 10V). Connect the ends of the winding to 1 and 3 and the centre tap to pin 3.

    0 Not allowed! Not allowed!

  3. #3
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by Dave H View Post
    It's a full wave rectifier. It needs a centre tapped transformer winding. Something like 7-0-7 volts should do it (as the input capacitors look to be only rated at 10V). Connect the ends of the winding to 1 and 3 and the centre tap to pin 3.
    Ok did that getting intermittant DC at the back to back diode thingy( barrier diode?) Says IR81 C4P038 on it. I'm not finding anything on it anyone have suggestions?
    I included a pic.

    nosaj
    Click image for larger version. 

Name:	IMG_20190715_183312632.jpg 
Views:	12 
Size:	3.45 MB 
ID:	54342

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  4. #4
    Supporting Member The Dude's Avatar
    Join Date
    May 2010
    Location
    Sioux Falls, SD
    Posts
    6,037
    Thumbs Up/Down
    Received: 1,010/1
    Given: 785/1
    Rep Power
    16
    Can you share the entire power supply schematic? It's hard to help without knowing what you're working on. Sans that, it sounds like it's trying to start and then going in to protect- cycling. If that's the case, check secondary supply diodes. Check secondary outputs to ground and see if one of your supply lines is shorted.

    0 Not allowed! Not allowed!
    “Yeah, well, you know, that’s just, like, your opinion, man.”

  5. #5
    Senior Member
    Join Date
    May 2006
    Location
    Cheshire, UK
    Posts
    2,104
    Thumbs Up/Down
    Received: 417/4
    Given: 241/0
    Rep Power
    16
    Quote Originally Posted by Dave H View Post
    Connect the ends of the winding to 1 and 3 and the centre tap to pin 3.
    Typo, that should read centre tap to pin 2

    0 Not allowed! Not allowed!

  6. #6
    Senior Member
    Join Date
    May 2006
    Location
    Cheshire, UK
    Posts
    2,104
    Thumbs Up/Down
    Received: 417/4
    Given: 241/0
    Rep Power
    16
    Quote Originally Posted by nosaj View Post
    Ok did that getting intermittant DC at the back to back diode thingy( barrier diode?) Says IR81 C4P038 on it. I'm not finding anything on it anyone have suggestions?
    It looks like C4P03Q on the schematic which is a dual Schottky rectifier - C4P03Q.pdf

    Where exactly are you measuring?

    0 Not allowed! Not allowed!
    Last edited by Dave H; Yesterday at 03:09 AM.

  7. #7
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by The Dude View Post
    Can you share the entire power supply schematic? It's hard to help without knowing what you're working on. Sans that, it sounds like it's trying to start and then going in to protect- cycling. If that's the case, check secondary supply diodes. Check secondary outputs to ground and see if one of your supply lines is shorted.
    Sure, Just know this , the amp is in the shop the organ is at the owners house. I have a transformer rigged up to J17 which is connected to pins 1 and 3 and ct'ed to pin2 .
    I get no voltage at the fuse. Next step is gonna be just pull out the diode thingy(does anyone know what to call it?) and run solo and see what voltage if any it produces.
    Here's a link page 12 is what you want. https://elektrotanya.com/kurzweil_k1...wnload.html#dl
    Thanks,
    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  8. #8
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by Dave H View Post
    It looks like C4P03Q on the schematic which is a dual Schottky rectifier.
    Where exactly are you measuring?
    Guess an 8 and a Q are not the same.
    Black lead ground pin2 and the other at the fuse.
    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  9. #9
    Senior Member
    Join Date
    May 2006
    Location
    Cheshire, UK
    Posts
    2,104
    Thumbs Up/Down
    Received: 417/4
    Given: 241/0
    Rep Power
    16
    Quote Originally Posted by nosaj View Post
    Guess an 8 and a Q are not the same.
    Black lead ground pin2 and the other at the fuse.
    nosaj
    Looking at the picture it could be a funny Q as it's not the same as the 8 above it.
    It should measure DC there. I suppose you've checked the fuse?
    Do the diodes measure OK in the C4P03 thingy ? Vf should be lower than silicon. I've attached a data sheet above.

    0 Not allowed! Not allowed!

  10. #10
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by Dave H View Post
    Looking at the picture it could be a funny Q as it's not the same as the 8 above it.
    It should measure DC there. I suppose you've checked the fuse?
    Do the diodes measure OK in the C4P03 thingy ? Vf should be lower than silicon. I've attached a data sheet above.
    No I've not checked the fuse as the voltage wasn't making it to the fuse, just to be sure I checked both fuse connectors earlier.
    On diode test it was measuring about .123 one way and OL the other. The low number was questionable for me, but being schottkey prob ok. But it still isn't passing rectified voltage. On pins 1 I get 12vac pin3 12vac pin2 0 So I'm getting input voltage to c4p03q.

    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  11. #11
    Supporting Member The Dude's Avatar
    Join Date
    May 2010
    Location
    Sioux Falls, SD
    Posts
    6,037
    Thumbs Up/Down
    Received: 1,010/1
    Given: 785/1
    Rep Power
    16
    That diode package is just 2 schottky diodes in one package. You should be able to just check them as 2 separate diodes- low resistance one direction and high the other. Is there AC all the way to the diode package (eliminate a connection issue). Is the fuse good? The smoothing cap(s) is/are on the other side of the fuse, so there will be a higher AC content at the diodes with the caps basically disconnected (if the fuse is open).

    0 Not allowed! Not allowed!
    Last edited by The Dude; Yesterday at 04:52 AM.
    “Yeah, well, you know, that’s just, like, your opinion, man.”

  12. #12
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by The Dude View Post
    That diode package is just 2 schottky diodes in one package. You should be able to just check them as 2 separate diodes- low resistance one direction and high the other. Is there AC all the way to the diode package (eliminate a connection issue). Is the fuse good? The smoothing cap(s) is/are on the other side of the fuse, so there will be a higher AC content at the diodes with the caps basically disconnected (if the fuse is open).
    Fuse is good. i used a dc regulated supply about 8v clipped on diode side of fuse holder. Checked voltage at the 5v regulator looks shot also I see 8 volts on all 3 terminals.

    Customer complaint was kids were having a hard time getting it to start and would rock the power switch several times to get it to go until it finally stopped responding over a week.

    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  13. #13
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by nosaj View Post
    Fuse is good. i used a dc regulated supply about 8v clipped on diode side of fuse holder. Checked voltage at the 5v regulator looks shot also I see 8 volts on all 3 terminals.

    Customer complaint was kids were having a hard time getting it to start and would rock the power switch several times to get it to go until it finally stopped responding over a week.

    nosaj
    Is there an alternative for a 3052v regulator? i could only find 10 pcs for $17 kinda steep.

    Thanks,
    Jason

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  14. #14
    Supporting Member The Dude's Avatar
    Join Date
    May 2010
    Location
    Sioux Falls, SD
    Posts
    6,037
    Thumbs Up/Down
    Received: 1,010/1
    Given: 785/1
    Rep Power
    16
    Is there a substantial enough heatsink that you could just use a TO220 5v reg? If so, I don't see why that wouldn't work as long as current capability is at least 2 amps like the original part. You'd probably have to run wires from legs to board, but the basing diagram will be different anyway.

    1 Not allowed! Not allowed!
    “Yeah, well, you know, that’s just, like, your opinion, man.”

  15. #15
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by The Dude View Post
    Is there a substantial enough heatsink that you could just use a TO220 5v reg? If so, I don't see why that wouldn't work as long as current capability is at least 2 amps like the original part. You'd probably have to run wires from legs to board, but the basing diagram will be different anyway.
    Not sure how I'd mount it. Here's some pics of board and heatsink. Put an apple phone charger on board for size reference.
    nosajClick image for larger version. 

Name:	IMG_20190716_192132151_HDR.jpg 
Views:	8 
Size:	3.31 MB 
ID:	54355Click image for larger version. 

Name:	IMG_20190716_192225522.jpg 
Views:	4 
Size:	3.52 MB 
ID:	54356

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  16. #16
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by nosaj View Post
    Not sure how I'd mount it. Here's some pics of board and heatsink. Put an apple phone charger on board for size reference.
    nosajClick image for larger version. 

Name:	IMG_20190716_192132151_HDR.jpg 
Views:	8 
Size:	3.31 MB 
ID:	54355Click image for larger version. 

Name:	IMG_20190716_192225522.jpg 
Views:	4 
Size:	3.52 MB 
ID:	54356
    Some reason I was thinking t03 instead of to220. i found this regulator L78S05CV and do 2amps.

    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  17. #17
    Supporting Member The Dude's Avatar
    Join Date
    May 2010
    Location
    Sioux Falls, SD
    Posts
    6,037
    Thumbs Up/Down
    Received: 1,010/1
    Given: 785/1
    Rep Power
    16
    Just pay attention to the basing diagram.

    0 Not allowed! Not allowed!
    “Yeah, well, you know, that’s just, like, your opinion, man.”

  18. #18
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by The Dude View Post
    Just pay attention to the basing diagram.
    Yea i pulled those up, flying leads it will be.

    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

  19. #19
    Don't forget the joker g1's Avatar
    Join Date
    Feb 2010
    Location
    Canada, somewhere north of Fargo
    Posts
    11,405
    Thumbs Up/Down
    Received: 1,351/21
    Given: 3,337/8
    Rep Power
    22
    While you're in there, how's that ni-cad holding up?
    Used to be we would disconnect the charging circuit and put a lithium coin cell in when they needed replacing.

    0 Not allowed! Not allowed!
    Just because they don't have tubes doesn't mean they don't have feelings! - glebert

  20. #20
    Master Destroyer nosaj's Avatar
    Join Date
    Sep 2011
    Location
    Pace, FL
    Posts
    3,054
    Thumbs Up/Down
    Received: 968/100
    Given: 139/35
    Rep Power
    11
    Quote Originally Posted by g1 View Post
    While you're in there, how's that ni-cad holding up?
    Used to be we would disconnect the charging circuit and put a lithium coin cell in when they needed replacing.
    That is actually a lithium, but since organ was made around 85-88 I intended on changing it anyways just to prevent a leakage.

    nosaj

    0 Not allowed! Not allowed!
    Binkie McFartnuggets‏:If we really wanted to know the meaning of life we would have fed Stephen Hawking shrooms a long time ago.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Power supply question
    By E biddy in forum Theory & Design
    Replies: 12
    Last Post: 06-01-2018, 01:44 AM
  2. Power Supply Question
    By Paleo Pete in forum Guitar Effects
    Replies: 8
    Last Post: 11-19-2016, 03:58 PM
  3. Power Supply Question
    By RobbieAG in forum Guitar Effects
    Replies: 3
    Last Post: 12-14-2009, 05:56 PM
  4. Power Supply Question
    By MarshallPlexi in forum Theory & Design
    Replies: 7
    Last Post: 02-06-2009, 08:32 AM
  5. Power supply question
    By bluefoxicy in forum Theory & Design
    Replies: 8
    Last Post: 04-13-2008, 10:32 PM

Bookmarks

Posting Permissions

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