Round pin DIP socket versus non round pin DIP sockets?

Discussion in 'General Electronics Chat' started by sdowney717, Apr 29, 2015.

  1. sdowney717

    Thread Starter Member

    Jul 18, 2012
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    These are ok to use either type for a standard DIP chip?
    What is with the round, is that an advantage? better quality?

    I need to replace mosfet driver 8 pin dip chips and being they are a pain to unsolder, I want to just get some sockets.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    They are better quality and generally you pay a little more for machined pins.
    Max.
     
  3. sdowney717

    Thread Starter Member

    Jul 18, 2012
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    Thanks, so I can just plug in my rectangular DIP chips into these round sockets same as regular?
    I dont think they make round DIP chip legs, right, not that I have seen anyway.

    Do the DIP chips go in and out same or easier you think as standard sockets?

    Some of these are saying 'solder type'
    I hope they dont mean you solder the socket to board, then solder chip to socket.
    I dont have experience with these, so I need to know.
     
    Last edited: Apr 29, 2015
  4. jpanhalt

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    Jan 18, 2008
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    In my experience, regular DIP chips will be harder to remove from the round ("machined") sockets. If it is something you will be putting in and taking out repeatedly, I would use a dip socket with spring pins. You can buy them in strips and in specific sockets, such as DIP16 or DIP8.

    John
     
  5. sdowney717

    Thread Starter Member

    Jul 18, 2012
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    http://www.mouser.com/Search/ProductDetail.aspx?R=MC33152PGvirtualkey58410000virtualkey863-MC33152PG

    Seems these spring sockets have a 1 amp rating. The chip has a 1.5 amp rating.
    Any thoughts on that? Would the spring socket fail?
    Then I read the machined ones also fail, they dont like to be reinserted over and over.

    I hate the soldered in dip chip so much.
    I am even thinking of soldering 8 wires to the DIP chip and solder the wires to the board holes!

    Ok, round pin may be the way to go as they show a 3 amp rating
    http://www.alliedelec.com/mill-max-110-13-316-41-001000/70206543/
     
    Last edited: Apr 29, 2015
  6. jpanhalt

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  7. sdowney717

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    Jul 18, 2012
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  8. MaxHeadRoom

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    Jul 18, 2013
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    To me, if you want repeated or often remove and replace, I would tend to use a ZIF socket?
    Max.
     
  9. sdowney717

    Thread Starter Member

    Jul 18, 2012
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    Nice idea! I dont plan to remove these mosfet drivers unless I blow up the board again, except of course the way things happen anything is possible.
    But wont exist any in 8 pin DIP?
    http://www.diystompboxes.com/smfforum/index.php?topic=42881.0;wap2

    I cant fit a big socket, the board has these DIP chips inline right next to each other.

    I finally went with this.
    http://www.digikey.com/product-search/en?KeyWords=ED90032-ND&WT.z_header=search_go

    So many choices, this one seemed good.
     
    Last edited: Apr 30, 2015
  10. sdowney717

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    Jul 18, 2012
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    It is working once again, this '3000' watt Peak power inverter!

    Here is a pic showing the DIP sockets, they are very nice indeed.
    [​IMG]

    I put a little moly grease and they slide right in, and they come right out, no troubles.

    I am wondering about the builtin overload protection circuit, if it works.
    How can I test that, without destroying the inverter?
    It is running off a 2 amp 12vdc battery charger (switch set to 2 amps).
    I momentarily connected the 120vac output leads for less than half a second, to see if the inverter shuts down, and got quite a spark. But no, it did not shut down. I was wondering if it would error with a red led, but it stayed green.

    Do you think it is current sensing or voltage sensing overloads?
    IF It is on a 2 amp 12vdc power source and I short the output, and then turn it on, will it not start up? Will it shut down with an error? Will it continue to try to run?
    Would that test the overload protection circuit? I also wonder if that is enough power to trigger a shut down.

    Any thoughts?

    Here is the output board, that converts DC to AC. I think the large cylinder resistors are they the current sensing resistors?
    [​IMG]
     
  11. kubeek

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    You put molybdenum grease? In the contacts? That´s a terrible idea. The contacts should be bare and clean and definitely not greased.
    Not only is easy sliding in and out undesirable as the chip might eventually fall out from the socket due to thermal expansion and vibration, but also the conctact resistance will be increased as the grease will cover the surface of the contacts.

    I suggest you get new sockets and this time put the chips in without any additives.
     
  12. ErnieM

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    Apr 24, 2011
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    There is a contact lubricant that can be used. It goes by the trade name "Nygel" and AFAIK is a "grease-like silicone heavily filled with heat-conductive metal oxides."

    Works well as a guard against fretting.
     
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  13. ian field

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    Oct 27, 2012
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    Also I find the leaf contacts in the cheap ones sometimes dig into the tin plating on the pins - when you try to take the chip out, it rips out the contact leaf.

    AFAIK: the turned pin sockets provide lower thermal resistance from the chip pins to the board and copper tracks.

    There's also a maximum frequency limit for sockets - and its probably higher for the turned pin types.
     
  14. sdowney717

    Thread Starter Member

    Jul 18, 2012
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    Ok, I looked at it and it is Valvolene synthetic wheel bearing grease, not particularly moly grease.
    They went in smoothly and are tightly secured, they wont be falling out. Just a light smearing of grease only on the pins.
    I had been reading how some people bend pins and find these sockets difficult to insert chips.
    I had no troubles at all.
    The inverter is happily running. There is no additional load on a mosfet driver chip as the loads vary, (AFAIK), it is on and off, the load is born by the mosfets.
    Definitely it is working just fine with the grease. I have used that grease on glass fuses and other bolt together lugs, it works just great to prevent corrosion on the wires in the boat. The boat is in salt water.

    A couple 1 amp glass fuses I installed with no grease in those plastic spring holders, and in a weak, the connection went high resistance and the meters did not come on. The fuse ends had a slight corrosion enough to prevent the electricity from flowing. Rubbing on some grease and they have been working fine for months like that.
     
    Last edited: May 11, 2015
  15. jpanhalt

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    Be careful with moly. It is for high pressure, but is not very good in corrosive environments (e.g. with water). For almost all of my implements I use regular EP grease without moly.

    Glad it worked for you.

    John
     
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  16. sdowney717

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    Jul 18, 2012
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    Yes, your right about moly and water, it can be a problem. Even greases can be washed away. Lithium based grease is better if things are going to be getting wet.
     
  17. ian field

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    Oct 27, 2012
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    Grease is probably best avoided, especially if there's a cooling fan - it'll stick to every bit of crud that convects/blows through the equipment.

    If you really must use lubricant, there is/was one made for the job. The one I knew of was Elvolube contacr grease - but I've done several searches and couldn't find any.

    The sort of place that would know what its called nowadays, is calibration houses - they use it on the brass button and wiper contacts on the big heavy duty resistance decade boxes.
     
  18. sdowney717

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    Jul 18, 2012
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    There is not enough grease to attract any dust. Just enough grease that the DIP leads can easily slip into the socket, none is visible from the outside. I have a feeling that the grease will aid in the long term reliability especially if I have to replace those DIP chips. And also moisture, I think it will prevent corrosion from humidity getting into the sockets between the metals. If you recall opening computer cases, they are always loaded with dust and no grease on the chips.
    Power inverter is still working, it worked all day long. Typically this will be used a few hours maybe a few days a week. And is in a dust free area located in a cabinet under the galley sink on the boat. It is always dry and clean in there.
     
  19. ian field

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    Oct 27, 2012
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    I've never had much difficulty pushing ICs into the cheap sockets, except it isn't so immediately obvious when a slightly bent pin gets folded under.

    The big problem is sharp edges on the contact leaves that dig into the tin plating on the pins - it sometimes rips the contact leaf out of the plastic header when you pull the chip, lubricant will actually make that a very slight bit worse.

    When I restocked with sockets, I bought only the turned pin type.

    Sometimes I get scrap boards to harvest parts from, turned pin sockets most of the time can be recovered intact - the cheap ones are more likely to have damaged pins where they protrude from the solder, these snag as you try to pull the socket and keeping the solder molten melts the plastic header and it collapses.
     
  20. sdowney717

    Thread Starter Member

    Jul 18, 2012
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    Yes. one reason I bought that particular socket was it had a higher heat rating, I could imagine it melting when soldering. There are so many different socket choices to make, one I chose had gold flash which I figured would aid in long term connectivity quality. I had read people were complaining about the sockets bending pins, being hard to put in chips and take them out which is why I opted to try the grease. With my limited experience I could easily imagine me trying to push in a chip and the legs bending, then the leg breaking off in the socket. I did have to carefully align the chip legs to the socket as they were spread too wide. Maybe some of the insertion problems is people not being careful getting the legs into the holes? I was also concerned about someday needing to remove the mosfet driver chips if I blew up the inverter again and finding them fretted - stuck - corroded into the sockets.

    The inverter is still working great. I have been going out to the boat everyday this week and running tests on it.

    I have been thinking that IF for some odd future reason the socket had failed, rather than remove the socket and risk the board being damaged, why not just solder a new socket to the existing socket. I found it very difficult to remove the original chips from the board, the socket would be even harder. Maybe you could snip - cut the legs out from underneath.

    I eventually found crushing the chip in place with nippers, or snipping its legs off to be easiest. I did damage to one trace and had to repair with a piece of copper wire. Also the solder the OEM used was that lead free stuff which takes a lot of heat to melt. I dont like that type solder, I use leaded solders that flow well.

    I also tried heating a large rectangular piece of copper and applying to the soldered chip legs, but all that did was slightly burn the board, but not badly just discolored. Anyway I found I dont have the tools needed to easily replace dip chips.

    Maybe a solder sucker could work for this?
     
    Last edited: May 15, 2015
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