Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Which MOSFET for DCSSR

  1. #1
    Join Date
    Jan 2008
    Location
    Bristol, UK
    Posts
    27
    Post Thanks / Like

    Default Which MOSFET for DCSSR

    Looking at the DCSSR on the WIKI it suggests using either a RFP14N05L or STF20NF06 MOSFET. Looking in the UK I can only find the RFP14N05L MOSFET on http://uk.rs-online.com
    When I look for similar devices there are are whole lot of parameters or characteristics to compare. Obviously working voltage and current carrying capability are obvious but what other characteristics matter when looking for an alternative MOSFET for the DCSSR. I will be controlling 12V dc at no more than 6A using some dumb RGB strips like these http://www.lightingever.co.uk/12v-le...rproof-5m.html ( 2 units per channel ).
    Suggestions / guidance will be very much appreciated, thanks.
    192 + 12 Channels, P4 1.8GHz, Grinch & Parallel12, Win XP Sp3, Vixen 2.0
    [URL]http://tyzzerslights.org.uk/[/URL]

  2. #2
    Join Date
    Dec 2014
    Location
    Southern California
    Posts
    848
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    I used the STP16NF06L. I see that the website you quoted carries has a listing for. Since it is rated for 16 amps and I only load it to less than 1 amp, I don't have to worry about adding heat sinks.
    Kevin

    2017 - Pi3 w/FPP controlling 8 ESPixelsticks driving 1250pixels and 3 Arduino MEGAS communicating with ESP-01s driving 96 channels
    2016 - 184 channels of Blinking/Flashing using 4 Arduino MEGAs and cheap home-made props.

  3. #3
    Join Date
    Nov 2009
    Location
    Morrisburg, On, Canada
    Posts
    2,540
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    Well, ... since you can find the RFP14N05L in the UK why look for additional substitutes that requires further research? It's a 14 amp device @ 50V so it is well within your requirements.

  4. #4
    Join Date
    May 2007
    Posts
    5,341
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    You should use a heat-sink with the RFP14N05L, as it will end up dissipating somewhere around 3W if left on continuously with a 6A load (according to the graphs in the datasheet, it will typically saturate at 6A with about a 0.5V RDS).
    Phil

  5. #5
    Join Date
    Dec 2011
    Location
    UK S80 postcode
    Posts
    1,434
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    Hi, I've not had chance to try them yet but there are some FQPF13N06L's sat on my desk to do something simalar.
    RS are doing them in the UK with free shipping in packs of 5.

    http://uk.rs-online.com/web/p/produc...FdUaGwodquIFJA

  6. #6
    Join Date
    Jan 2008
    Location
    Bristol, UK
    Posts
    27
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    [Kev] RS components does carry a listing for the MOSFET but I'd rather see if I can find a cheaper alternative, but I don't know which of the characteristics I need to be concerned about other than Voltage & current.

    [Lightup] Thanks for the reply, I would look for alternatives but I don't know which of the characteristics I need to be concerned about.

    [P.Short] I would like to be able to do this without a heat-sink if I can, mainly for space, happy to use a higher current rated device. Due to lack of knowledge, what does RDS relate to?

    Thanks for your replies guy's.
    192 + 12 Channels, P4 1.8GHz, Grinch & Parallel12, Win XP Sp3, Vixen 2.0
    [URL]http://tyzzerslights.org.uk/[/URL]

  7. #7
    Join Date
    Jan 2008
    Location
    Bristol, UK
    Posts
    27
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    Hi Barnabybear,

    Thanks for that. What characteristics of the device make it a suitable alternative?
    I don't quite understand MOSFET's other than they appear to be power transistors of a sort.
    192 + 12 Channels, P4 1.8GHz, Grinch & Parallel12, Win XP Sp3, Vixen 2.0
    [URL]http://tyzzerslights.org.uk/[/URL]

  8. #8
    Join Date
    Nov 2009
    Location
    Morrisburg, On, Canada
    Posts
    2,540
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    ptyzzer:
    The basic characteristics are voltage, current, power, gate drive and thermal design.
    It was a course in my schooling so a blurb here wouldn't do full justice, as you are getting into design details. I haven't done this for some decades.
    You need to be able to decipher data sheets of the device you are going to use. You can start the process and have reviews done here.
    A solution can take time (and money in buying various parts) as some potential solution may use several very cheap devices and wire them in parallel. But you have to evaluate all the angles to determine if it really is cheaper, or worth the bother.

    I don't have the cheapest solution for you waiting to be built.

    Generally you pick a working design already tested by members here and go with it.

    Edit:
    There is also a software way of designing by using, say LTSpiceIV.
    http://www.linear.com/designtools/software/#LTspice
    How close it comes to the real world would need to be evaluated by building a prototype and testing it.
    Last edited by LightUp; 12-16-2016 at 01:54 PM.

  9. Thanks ptyzzer thanked for this post
  10. #9
    Join Date
    Dec 2014
    Location
    Southern California
    Posts
    848
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    Quote Originally Posted by ptyzzer View Post
    [Kev] ....... but I'd rather see if I can find a cheaper alternative.......
    Yeah. Not sure what your cost is, but I paid $0.25 each two years ago for 100 pieces. They are now $0.33 each for 100 pieces from Avnet, more if you buy less quantity.
    My 16 channel DC SSR boards cost less than $1.00 per channel (actual cost of board and components at the time).
    Kevin

    2017 - Pi3 w/FPP controlling 8 ESPixelsticks driving 1250pixels and 3 Arduino MEGAS communicating with ESP-01s driving 96 channels
    2016 - 184 channels of Blinking/Flashing using 4 Arduino MEGAs and cheap home-made props.

  11. Thanks ptyzzer thanked for this post
  12. #10
    Join Date
    Dec 2014
    Location
    Southern California
    Posts
    848
    Post Thanks / Like

    Default Re: Which MOSFET for DCSSR

    I built 8 of those for my show this year
    Last edited by kev; 12-16-2016 at 02:20 PM.
    Kevin

    2017 - Pi3 w/FPP controlling 8 ESPixelsticks driving 1250pixels and 3 Arduino MEGAS communicating with ESP-01s driving 96 channels
    2016 - 184 channels of Blinking/Flashing using 4 Arduino MEGAs and cheap home-made props.

Page 1 of 2 12 LastLast

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
  •