Loading ...
Sorry, an error occurred while loading the content.

Re: [Electronics_101] Re: Useful info on SCR's

Expand Messages
  • DaveC
    OK, I m now straight on the fact that perm links are the only ones that work. But HOW do you get a perm link? Thanks, Dave -=-=-=-
    Message 1 of 28 , Feb 1, 2012
    • 0 Attachment
      OK, I'm now straight on the fact that perm links are the only ones that work.

      But HOW do you get a perm link?

      Thanks,
      Dave

      -=-=-=-

      >Hah! That was actually Dave himself who helpfully posted it.
      >
      >Dave, if the old link works, it may be because it is still in your cache.
      >
      >Anyway, just trying to help remind people how to post links to
      >Files. Back to the discussion.
      >
      >Steve Greenfield AE7HD
    • Donald H Locker
      The link to the directory holding the file is permanent, so you can grab that from the browser s navigation bar. Drop a / (if necessary) and the file name
      Message 2 of 28 , Feb 1, 2012
      • 0 Attachment
        The link to the directory holding the file is permanent, so you can grab that from the browser's navigation bar. Drop a '/' (if necessary) and the file name (exactly as spelled) after that and you should be good. You will have to substitute '%20" in place of any space characters (which is one reason they are evil) or your URL might get split at the whitespace.

        I navigated to the '1630 Hz Oscillator' directory and copied this string from the navigation bar:

        "http://groups.yahoo.com/group/Electronics_101/files/1630%20Hz%20Oscillator/"

        Then to make a link to "16step 1 phase.asc", I paste the two together and substitute for the space characters to get (with <> around which discourages most mailers from splitting the line.)

        <http://groups.yahoo.com/group/Electronics_101/files/1630%20Hz%20Oscillator/16step%201%20phase.asc>

        HTH,
        Donald.
        --
        *Plain Text* email -- it's an accessibility issue
        () no proprietary attachments; no html mail
        /\ ascii ribbon campaign - <www.asciiribbon.org>

        ----- Original Message -----
        > From: "DaveC" <davec2468@...>
        > To: "Electronics 101" <Electronics_101@yahoogroups.com>
        > Sent: Wednesday, February 1, 2012 10:25:31 AM
        > Subject: Re: [Electronics_101] Re: Useful info on SCR's
        > OK, I'm now straight on the fact that perm links are the only ones
        > that work.
        >
        > But HOW do you get a perm link?
        >
        > Thanks,
        > Dave
        >
        > -=-=-=-
        >
        > >Hah! That was actually Dave himself who helpfully posted it.
        > >
        > >Dave, if the old link works, it may be because it is still in your
        > >cache.
        > >
        > >Anyway, just trying to help remind people how to post links to
        > >Files. Back to the discussion.
        > >
        > >Steve Greenfield AE7HD
        >
        >
        > ------------------------------------
        >
        > Please trim excess when replyingYahoo! Groups Links
        >
        >
        >
      • AlienRelics
        Did you get a chance? Steve Greenfield AE7HD
        Message 3 of 28 , Feb 3, 2012
        • 0 Attachment
          Did you get a chance?

          Steve Greenfield AE7HD

          --- In Electronics_101@yahoogroups.com, Donald H Locker <dhlocker@...> wrote:
          >
          > If I get a chance, I'll fire up LTspice and run some simulations and capture some waveforms. The inductor will slow the rate of rise of current as Steve points out, and the contacts won't switch that full current (unless they are opened at an inopportune time,) but they still have to carry the full current. If they don't, there will be load current flowing through the SCR and preventing it from commutating.
          >
          > I worked on some large SCR inverters many years ago, commutated with SCRs in the place of the switches (like fig 1-12), and they certainly carried full current. The advantage of the two-SCR commutation was that the commutating SCR automatically opened at the right time as it was commutated by the LC ring.
          >
          > Donald.
          > --
          > *Plain Text* email -- it's an accessibility issue
          > () no proprietary attachments; no html mail
          > /\ ascii ribbon campaign - <www.asciiribbon.org>
          >
        • Donald H Locker
          Not yet. Probably tomorrow. Donald. -- *Plain Text* email -- it s an accessibility issue () no proprietary attachments; no html mail / ascii ribbon
          Message 4 of 28 , Feb 3, 2012
          • 0 Attachment
            Not yet. Probably tomorrow.

            Donald.
            --
            *Plain Text* email -- it's an accessibility issue
            () no proprietary attachments; no html mail
            /\ ascii ribbon campaign - <www.asciiribbon.org>

            ----- Original Message -----
            > From: "AlienRelics" <alienrelics@...>
            > To: "Electronics 101" <Electronics_101@yahoogroups.com>
            > Sent: Friday, February 3, 2012 2:52:29 PM
            > Subject: [Electronics_101] Re: Useful info on SCR's
            > Did you get a chance?
            >
            > Steve Greenfield AE7HD
            >
            > --- In Electronics_101@yahoogroups.com, Donald H Locker <dhlocker@...>
            > wrote:
            > >
            > > If I get a chance, I'll fire up LTspice and run some simulations and
            > > capture some waveforms. The inductor will slow the rate of rise of
            > > current as Steve points out, and the contacts won't switch that full
            > > current (unless they are opened at an inopportune time,) but they
            > > still have to carry the full current. If they don't, there will be
            > > load current flowing through the SCR and preventing it from
            > > commutating.
            > >
            > > I worked on some large SCR inverters many years ago, commutated with
            > > SCRs in the place of the switches (like fig 1-12), and they
            > > certainly carried full current. The advantage of the two-SCR
            > > commutation was that the commutating SCR automatically opened at the
            > > right time as it was commutated by the LC ring.
            > >
            > > Donald.
            > > --
            > > *Plain Text* email -- it's an accessibility issue
            > > () no proprietary attachments; no html mail
            > > /\ ascii ribbon campaign - <www.asciiribbon.org>
            > >
            >
            >
            >
            > ------------------------------------
            >
            > Please trim excess when replyingYahoo! Groups Links
            >
            >
            >
          • Donald H Locker
            I just uploaded a model that demonstrates the essential behaviour of the commutation circuit. The funny thing I found is that the switch actually carries more
            Message 5 of 28 , Feb 4, 2012
            • 0 Attachment
              I just uploaded a model that demonstrates the essential behaviour of the commutation circuit. The funny thing I found is that the switch actually carries more than the load current with this circuit - the LC pulling down the anode of the SCR reverse biases the SCR and until the junctions' charge is fully depleted, significant reverse current flows through the SCR. The amount of excess current can be modified to some extent by altering component values and choosing different SCRs. I just used the first SCR that I could trigger on and off reliably with the components chosen.

              HTH, and feel free to criticize, modify, experiment, ...
              Donald.
              --
              *Plain Text* email -- it's an accessibility issue
              () no proprietary attachments; no html mail
              /\ ascii ribbon campaign - <www.asciiribbon.org>

              ----- Original Message -----
              > From: "AlienRelics" <alienrelics@...>
              > To: "Electronics 101" <Electronics_101@yahoogroups.com>
              > Sent: Friday, February 3, 2012 2:52:29 PM
              > Subject: [Electronics_101] Re: Useful info on SCR's
              > Did you get a chance?
              >
              > Steve Greenfield AE7HD
              >
              > --- In Electronics_101@yahoogroups.com, Donald H Locker <dhlocker@...>
              > wrote:
              > >
              > > If I get a chance, I'll fire up LTspice and run some simulations and
              > > capture some waveforms. The inductor will slow the rate of rise of
              > > current as Steve points out, and the contacts won't switch that full
              > > current (unless they are opened at an inopportune time,) but they
              > > still have to carry the full current. If they don't, there will be
              > > load current flowing through the SCR and preventing it from
              > > commutating.
              > >
              > > I worked on some large SCR inverters many years ago, commutated with
              > > SCRs in the place of the switches (like fig 1-12), and they
              > > certainly carried full current. The advantage of the two-SCR
              > > commutation was that the commutating SCR automatically opened at the
              > > right time as it was commutated by the LC ring.
              > >
              > > Donald.
              > > --
              > > *Plain Text* email -- it's an accessibility issue
              > > () no proprietary attachments; no html mail
              > > /\ ascii ribbon campaign - <www.asciiribbon.org>
              > >
              >
              >
              >
              > ------------------------------------
              >
              > Please trim excess when replyingYahoo! Groups Links
              >
              >
              >
            • Nuno T.
              Thank you. Was curious about that too. Nuno
              Message 6 of 28 , Feb 4, 2012
              • 0 Attachment
                Thank you. Was curious about that too.

                Nuno

                > -----Original Message-----
                > From: Electronics_101@yahoogroups.com
                > [mailto:Electronics_101@yahoogroups.com] On Behalf Of Donald H Locker
                > Sent: sábado, 4 de Fevereiro de 2012 19:23
                > To: Electronics 101
                > Subject: Re: [Electronics_101] Re: Useful info on SCR's
                >
                > I just uploaded a model that demonstrates the essential
                > behaviour of the commutation circuit. The funny thing I
                > found is that the switch actually carries more than the load
                > current with this circuit - the LC pulling down the anode of
                > the SCR reverse biases the SCR and until the junctions'
                > charge is fully depleted, significant reverse current flows
                > through the SCR. The amount of excess current can be
                > modified to some extent by altering component values and
                > choosing different SCRs. I just used the first SCR that I
                > could trigger on and off reliably with the components chosen.
                >
                > HTH, and feel free to criticize, modify, experiment, ...
                > Donald.
                > --
                > *Plain Text* email -- it's an accessibility issue
                > () no proprietary attachments; no html mail /\ ascii ribbon
                > campaign - <www.asciiribbon.org>
                >
                > ----- Original Message -----
                > > From: "AlienRelics" <alienrelics@...>
                > > To: "Electronics 101" <Electronics_101@yahoogroups.com>
                > > Sent: Friday, February 3, 2012 2:52:29 PM
                > > Subject: [Electronics_101] Re: Useful info on SCR's Did you get a
                > > chance?
                > >
                > > Steve Greenfield AE7HD
                > >
                > > --- In Electronics_101@yahoogroups.com, Donald H Locker
                > <dhlocker@...>
                > > wrote:
                > > >
                > > > If I get a chance, I'll fire up LTspice and run some
                > simulations and
                > > > capture some waveforms. The inductor will slow the rate
                > of rise of
                > > > current as Steve points out, and the contacts won't
                > switch that full
                > > > current (unless they are opened at an inopportune time,) but they
                > > > still have to carry the full current. If they don't,
                > there will be
                > > > load current flowing through the SCR and preventing it from
                > > > commutating.
                > > >
                > > > I worked on some large SCR inverters many years ago,
                > commutated with
                > > > SCRs in the place of the switches (like fig 1-12), and they
                > > > certainly carried full current. The advantage of the two-SCR
                > > > commutation was that the commutating SCR automatically
                > opened at the
                > > > right time as it was commutated by the LC ring.
                > > >
                > > > Donald.
                > > > --
                > > > *Plain Text* email -- it's an accessibility issue
                > > > () no proprietary attachments; no html mail /\ ascii
                > ribbon campaign
                > > > - <www.asciiribbon.org>
                > > >
                > >
                > >
                > >
                > > ------------------------------------
                > >
                > > Please trim excess when replyingYahoo! Groups Links
                > >
                > >
                > >
                >
                >
                > ------------------------------------
                >
                > Please trim excess when replyingYahoo! Groups Links
                >
                >
                >
              • Donald H Locker
                I just uploaded a .zip file with the three different circuits modeled. (1-9A, 1-11 and 1-12) All are guaranteed to simulate and reflect some semblance of
                Message 7 of 28 , Feb 4, 2012
                • 0 Attachment
                  I just uploaded a .zip file with the three different circuits modeled. (1-9A, 1-11 and 1-12) All are guaranteed to simulate and reflect some semblance of reality. It is in the same location and zip file as before: <http://groups.yahoo.com/group/Electronics_101/files/SCRcontrol/SCRcontrol.zip> I'll dig up the source of the SCR model I used so you can see how that person did it and look at alternatives.

                  I'm quite sure I pulled the models from <http://tech.groups.yahoo.com/group/LTspice/files/%20Lib/Yet%20Another%20SCR%20Model/> but Yahoo! isn't responding right now, so I can't absolutely confirm that.

                  Enjoy, and please check my work.
                  Donald.
                  --
                  *Plain Text* email -- it's an accessibility issue
                  () no proprietary attachments; no html mail
                  /\ ascii ribbon campaign - <www.asciiribbon.org>

                  ----- Original Message -----
                  > From: "AlienRelics" <alienrelics@...>
                  > To: "Electronics 101" <Electronics_101@yahoogroups.com>
                  > Sent: Friday, February 3, 2012 2:52:29 PM
                  > Subject: [Electronics_101] Re: Useful info on SCR's
                  > Did you get a chance?
                  >
                  > Steve Greenfield AE7HD
                  >
                  > --- In Electronics_101@yahoogroups.com, Donald H Locker <dhlocker@...>
                  > wrote:
                  > >
                  > > If I get a chance, I'll fire up LTspice and run some simulations and
                  > > capture some waveforms. The inductor will slow the rate of rise of
                  > > current as Steve points out, and the contacts won't switch that full
                  > > current (unless they are opened at an inopportune time,) but they
                  > > still have to carry the full current. If they don't, there will be
                  > > load current flowing through the SCR and preventing it from
                  > > commutating.
                  > >
                  > > I worked on some large SCR inverters many years ago, commutated with
                  > > SCRs in the place of the switches (like fig 1-12), and they
                  > > certainly carried full current. The advantage of the two-SCR
                  > > commutation was that the commutating SCR automatically opened at the
                  > > right time as it was commutated by the LC ring.
                  > >
                  > > Donald.
                  > > --
                  > > *Plain Text* email -- it's an accessibility issue
                  > > () no proprietary attachments; no html mail
                  > > /\ ascii ribbon campaign - <www.asciiribbon.org>
                  > >
                  >
                  >
                  >
                  > ------------------------------------
                  >
                  > Please trim excess when replyingYahoo! Groups Links
                  >
                  >
                  >
                • Donald H Locker
                  Just verified; was the source of the model I used.
                  Message 8 of 28 , Feb 4, 2012
                  • 0 Attachment
                    Just verified; <http://tech.groups.yahoo.com/group/LTspice/files/%20Lib/Yet%20Another%20SCR%20Model//Thyristors.zip> was the source of the model I used.

                    Donald.
                    --
                    *Plain Text* email -- it's an accessibility issue
                    () no proprietary attachments; no html mail
                    /\ ascii ribbon campaign - <www.asciiribbon.org>

                    ----- Original Message -----
                    > From: "Donald H Locker" <dhlocker@...>
                    > To: "Electronics 101" <Electronics_101@yahoogroups.com>
                    > Sent: Saturday, February 4, 2012 9:19:49 PM
                    > Subject: Re: [Electronics_101] Re: Useful info on SCR's
                    > I just uploaded a .zip file with the three different circuits modeled.
                    > (1-9A, 1-11 and 1-12) All are guaranteed to simulate and reflect some
                    > semblance of reality. It is in the same location and zip file as
                    > before:
                    > <http://groups.yahoo.com/group/Electronics_101/files/SCRcontrol/SCRcontrol.zip>
                    > I'll dig up the source of the SCR model I used so you can see how that
                    > person did it and look at alternatives.
                    >
                    > I'm quite sure I pulled the models from
                    > <http://tech.groups.yahoo.com/group/LTspice/files/%20Lib/Yet%20Another%20SCR%20Model/>
                    > but Yahoo! isn't responding right now, so I can't absolutely confirm
                    > that.
                    >
                    > Enjoy, and please check my work.
                    > Donald.
                    > --
                    > *Plain Text* email -- it's an accessibility issue
                    > () no proprietary attachments; no html mail
                    > /\ ascii ribbon campaign - <www.asciiribbon.org>
                    >
                    > ----- Original Message -----
                    > > From: "AlienRelics" <alienrelics@...>
                    > > To: "Electronics 101" <Electronics_101@yahoogroups.com>
                    > > Sent: Friday, February 3, 2012 2:52:29 PM
                    > > Subject: [Electronics_101] Re: Useful info on SCR's
                    > > Did you get a chance?
                    > >
                    > > Steve Greenfield AE7HD
                    > >
                    > > --- In Electronics_101@yahoogroups.com, Donald H Locker
                    > > <dhlocker@...>
                    > > wrote:
                    > > >
                    > > > If I get a chance, I'll fire up LTspice and run some simulations
                    > > > and
                    > > > capture some waveforms. The inductor will slow the rate of rise of
                    > > > current as Steve points out, and the contacts won't switch that
                    > > > full
                    > > > current (unless they are opened at an inopportune time,) but they
                    > > > still have to carry the full current. If they don't, there will be
                    > > > load current flowing through the SCR and preventing it from
                    > > > commutating.
                    > > >
                    > > > I worked on some large SCR inverters many years ago, commutated
                    > > > with
                    > > > SCRs in the place of the switches (like fig 1-12), and they
                    > > > certainly carried full current. The advantage of the two-SCR
                    > > > commutation was that the commutating SCR automatically opened at
                    > > > the
                    > > > right time as it was commutated by the LC ring.
                    > > >
                    > > > Donald.
                    > > > --
                    > > > *Plain Text* email -- it's an accessibility issue
                    > > > () no proprietary attachments; no html mail
                    > > > /\ ascii ribbon campaign - <www.asciiribbon.org>
                    > > >
                  Your message has been successfully submitted and would be delivered to recipients shortly.