• fast discrete PHEMT one-shot

    From John Larkin@21:1/5 to All on Wed May 15 09:47:57 2024
    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and
    high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All
    my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to John Larkin on Wed May 15 14:22:36 2024
    On 2024-05-15 12:47, John Larkin wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and
    high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All
    my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.


    With a low-resistance drain load like that, you don't care too much
    about the low drain impedance of the pHEMT. The old Avago ones were
    around 160 ohms iirc. The transconductance is high enough (400 mho or something ridiculous like that) that you get gobs of voltage gain even so.

    Really really crappy for followers though!

    Cheers

    Phil Hobbs

    --
    Dr Philip C D Hobbs
    Principal Consultant
    ElectroOptical Innovations LLC / Hobbs ElectroOptics
    Optics, Electro-optics, Photonics, Analog Electronics
    Briarcliff Manor NY 10510

    http://electrooptical.net
    http://hobbs-eo.com

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From piglet@21:1/5 to John Larkin on Wed May 15 22:46:27 2024
    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and
    high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All
    my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.


    --
    piglet

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to Phil Hobbs on Thu May 16 00:00:56 2024
    Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
    On 2024-05-15 12:47, John Larkin wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and
    high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All
    my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.


    With a low-resistance drain load like that, you don't care too much
    about the low drain impedance of the pHEMT. The old Avago ones were
    around 160 ohms iirc. The transconductance is high enough (400

    millimho or
    something ridiculous like that) that you get gobs of voltage gain even so.

    Really really crappy for followers though!

    Cheers

    Phil Hobbs




    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to erichpwagner@hotmail.com on Wed May 15 18:15:34 2024
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and
    high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All
    my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was
    invented.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Wed May 15 18:07:12 2024
    On Thu, 16 May 2024 00:00:56 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
    On 2024-05-15 12:47, John Larkin wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and
    high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All
    my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.


    With a low-resistance drain load like that, you don't care too much
    about the low drain impedance of the pHEMT. The old Avago ones were
    around 160 ohms iirc. The transconductance is high enough (400

    millimho or

    Rds-on is about 2 ohms with a half a volt or so on the gate.

    Interestingly, they seem to keep turning on harder with insane gate
    voltages, like +1 or so. Ig is about 16 mA, way past abs max, at 1
    volt, but I'll just pulse it so it will be fine. Right?



    something ridiculous like that) that you get gobs of voltage gain even so. >>
    Really really crappy for followers though!

    Tell me about that. My triggered 50 MHz colpitts oscillator squegged
    at around 4 GHz. Tons of jitter.

    I designed a new osc using a BUF602 and it's great.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to John Larkin on Thu May 16 02:14:49 2024
    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and
    high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All
    my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was
    invented.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.



    Probably because the classical TTL and CMOS multivibrator chips are so horrible.

    The CMOS versions of the 555 are about the best, which is amusing since they’re the ones that get all the abuse.

    My usual rule is that one-shots are fine if you can accommodate a factor of
    3 uncertainty in the delay.

    Joerg used to wrap feedback loops around them.

    Cheers

    Phil Hobbs

    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill Sloman@21:1/5 to John Larkin on Fri May 17 00:40:32 2024
    On 16/05/2024 11:15 am, John Larkin wrote:
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and
    high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All
    my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was > invented.

    https://en.wikipedia.org/wiki/Multivibrator

    has a two quotes from 1942 one from 1943 and two from 1949 which make it
    clear that monostable had been invented by then. It sees it as a cut
    down bistable, so Eccles-Jordan is probably a good name.

    Since the first multivibrator circuit, the astable multivibrator
    oscillator, was invented by Henri Abraham and Eugene Bloch during World
    War I, it probably isn't the right name.

    https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf

    is a 1963 Ph.D. on the bistable circuit.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.

    You can't trigger a one-shot immediately after it has been triggered,
    and the pulse width you get can be reduced if you re-trigger it too soon
    after it has generated it's pulse, when it hasn't entirely recovered.

    Using a properly terminated delay line to set the output pulse width
    could reduce this uncertainty, but I've never done it.

    Ghiggino, K.P., Phillips, D., and Sloman, A.W. "Nanosecond pulse stretcher",Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

    just used two 5GHz wide-band transistors (BFT95) and was perfectly
    horrible, but it did what Dave Phillips and Ken Ghiggino had wanted me
    to give them, and Ken Ghiggino wrote it up rather badly, but I was able
    to rework the short paper into a form that was publishable and looks
    nice on Ken's CV.

    The fact the laser pulses it was designed to detect arrived at a steady
    20MHz meant that it's worst defect didn't matter.

    --
    Bill Sloman, Sydney

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to All on Thu May 16 09:46:16 2024
    On Fri, 17 May 2024 00:40:32 +1000, Bill Sloman <bill.sloman@ieee.org>
    wrote:

    On 16/05/2024 11:15 am, John Larkin wrote:
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and >>>> high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All >>>> my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was > invented.

    https://en.wikipedia.org/wiki/Multivibrator

    has a two quotes from 1942 one from 1943 and two from 1949 which make it >clear that monostable had been invented by then. It sees it as a cut
    down bistable, so Eccles-Jordan is probably a good name.

    Since the first multivibrator circuit, the astable multivibrator
    oscillator, was invented by Henri Abraham and Eugene Bloch during World
    War I, it probably isn't the right name.

    https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf

    is a 1963 Ph.D. on the bistable circuit.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.

    You can't trigger a one-shot immediately after it has been triggered,
    and the pulse width you get can be reduced if you re-trigger it too soon >after it has generated it's pulse, when it hasn't entirely recovered.

    The SN74123 retriggerable one-shot, and a Fairchild equivalent, are
    over 50 years old.

    And "it's" is not the possessive form. It's means "it is."

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Edward Rawde@21:1/5 to John Larkin on Thu May 16 16:41:15 2024
    "John Larkin" <jjSNIPlarkin@highNONOlandtechnology.com> wrote in message news:9qdc4jdovsm0rousj88ngtn2bj6env9l48@4ax.com...
    On Fri, 17 May 2024 00:40:32 +1000, Bill Sloman <bill.sloman@ieee.org>
    wrote:

    On 16/05/2024 11:15 am, John Larkin wrote:
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and >>>>> high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch. >>>>>
    I can post a link to the files if anybody wants to play with this. All >>>>> my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a >>>>> typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was >
    invented.

    https://en.wikipedia.org/wiki/Multivibrator

    has a two quotes from 1942 one from 1943 and two from 1949 which make it >>clear that monostable had been invented by then. It sees it as a cut
    down bistable, so Eccles-Jordan is probably a good name.

    Since the first multivibrator circuit, the astable multivibrator >>oscillator, was invented by Henri Abraham and Eugene Bloch during World
    War I, it probably isn't the right name.

    https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf

    is a 1963 Ph.D. on the bistable circuit.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.

    You can't trigger a one-shot immediately after it has been triggered,
    and the pulse width you get can be reduced if you re-trigger it too soon >>after it has generated it's pulse, when it hasn't entirely recovered.

    The SN74123 retriggerable one-shot, and a Fairchild equivalent, are
    over 50 years old.

    And "it's" is not the possessive form. It's means "it is."

    But it can also mean "it has" and who cares anyway.
    I often find, when typing fast, that I used the wrong form when I re read my sentence.
    I even typed dentence then and had to change the d.

    One-shots were frequently used in logic designs when gates were four per package because designers still knew what they were doing with components
    such as resistors, capacitors, inductors etc.
    I'm sure some still do but not many.
    50 years from now it will likely all be done by AD. (Artificial Designer).

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Larkin@21:1/5 to invalid@invalid.invalid on Thu May 16 19:04:32 2024
    On Thu, 16 May 2024 16:41:15 -0400, "Edward Rawde"
    <invalid@invalid.invalid> wrote:

    "John Larkin" <jjSNIPlarkin@highNONOlandtechnology.com> wrote in message >news:9qdc4jdovsm0rousj88ngtn2bj6env9l48@4ax.com...
    On Fri, 17 May 2024 00:40:32 +1000, Bill Sloman <bill.sloman@ieee.org>
    wrote:

    On 16/05/2024 11:15 am, John Larkin wrote:
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and >>>>>> high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch. >>>>>>
    I can post a link to the files if anybody wants to play with this. All >>>>>> my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a >>>>>> typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was >
    invented.

    https://en.wikipedia.org/wiki/Multivibrator

    has a two quotes from 1942 one from 1943 and two from 1949 which make it >>>clear that monostable had been invented by then. It sees it as a cut
    down bistable, so Eccles-Jordan is probably a good name.

    Since the first multivibrator circuit, the astable multivibrator >>>oscillator, was invented by Henri Abraham and Eugene Bloch during World >>>War I, it probably isn't the right name.

    https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf

    is a 1963 Ph.D. on the bistable circuit.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.

    You can't trigger a one-shot immediately after it has been triggered,
    and the pulse width you get can be reduced if you re-trigger it too soon >>>after it has generated it's pulse, when it hasn't entirely recovered.

    The SN74123 retriggerable one-shot, and a Fairchild equivalent, are
    over 50 years old.

    And "it's" is not the possessive form. It's means "it is."

    But it can also mean "it has" and who cares anyway.
    I often find, when typing fast, that I used the wrong form when I re read my >sentence.
    I even typed dentence then and had to change the d.

    You've got to admit that his pompous lecture, about all the inherent
    defects of one-shots, was amusing.

    I tweaked my phemt one-shot a bit, just for fun. I might even have a
    use for it.

    https://www.dropbox.com/scl/fi/zoncsuiz2ifl30i1tw0cl/Phemt_One-shot_2.jpg?rlkey=z77hx5kkdpijmz5rs7ex63jq7&raw=1


    One cool old circuit that predated ICs was the uni-shot, a single
    transistor and three passives. It was used in model airplane r/c
    transmitters. One of the three passives was a joystick pot.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill Sloman@21:1/5 to John Larkin on Fri May 17 15:37:13 2024
    On 17/05/2024 2:46 am, John Larkin wrote:
    On Fri, 17 May 2024 00:40:32 +1000, Bill Sloman <bill.sloman@ieee.org>
    wrote:

    On 16/05/2024 11:15 am, John Larkin wrote:
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and >>>>> high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch. >>>>>
    I can post a link to the files if anybody wants to play with this. All >>>>> my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a >>>>> typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was > invented.

    https://en.wikipedia.org/wiki/Multivibrator

    has a two quotes from 1942 one from 1943 and two from 1949 which make it
    clear that monostable had been invented by then. It sees it as a cut
    down bistable, so Eccles-Jordan is probably a good name.

    Since the first multivibrator circuit, the astable multivibrator
    oscillator, was invented by Henri Abraham and Eugene Bloch during World
    War I, it probably isn't the right name.

    https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf

    is a 1963 Ph.D. on the bistable circuit.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.

    You can't trigger a one-shot immediately after it has been triggered,
    and the pulse width you get can be reduced if you re-trigger it too soon
    after it has generated it's pulse, when it hasn't entirely recovered.

    The SN74123 retriggerable one-shot, and a Fairchild equivalent, are
    over 50 years old.

    But you don't get a new pulse when you retrigger a retriggerable
    monostable - you just stretch the one you had already started.

    And "it's" is not the possessive form. It's means "it is."

    I do know that but produce the mistake as a typo from time to time, as
    you are well aware.

    And you've snipped the rest of my post, without marking the snip.

    --
    Bill Sloman, Sydney

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill Sloman@21:1/5 to John Larkin on Fri May 17 15:43:33 2024
    On 17/05/2024 12:04 pm, John Larkin wrote:
    On Thu, 16 May 2024 16:41:15 -0400, "Edward Rawde"
    <invalid@invalid.invalid> wrote:

    "John Larkin" <jjSNIPlarkin@highNONOlandtechnology.com> wrote in message
    news:9qdc4jdovsm0rousj88ngtn2bj6env9l48@4ax.com...
    On Fri, 17 May 2024 00:40:32 +1000, Bill Sloman <bill.sloman@ieee.org>
    wrote:

    On 16/05/2024 11:15 am, John Larkin wrote:
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and >>>>>>> high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch. >>>>>>>
    I can post a link to the files if anybody wants to play with this. All >>>>>>> my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a >>>>>>> typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was >
    invented.

    https://en.wikipedia.org/wiki/Multivibrator

    has a two quotes from 1942 one from 1943 and two from 1949 which make it >>>> clear that monostable had been invented by then. It sees it as a cut
    down bistable, so Eccles-Jordan is probably a good name.

    Since the first multivibrator circuit, the astable multivibrator
    oscillator, was invented by Henri Abraham and Eugene Bloch during World >>>> War I, it probably isn't the right name.

    https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf

    is a 1963 Ph.D. on the bistable circuit.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.

    You can't trigger a one-shot immediately after it has been triggered,
    and the pulse width you get can be reduced if you re-trigger it too soon >>>> after it has generated it's pulse, when it hasn't entirely recovered.

    The SN74123 retriggerable one-shot, and a Fairchild equivalent, are
    over 50 years old.

    And "it's" is not the possessive form. It's means "it is."

    But it can also mean "it has" and who cares anyway.
    I often find, when typing fast, that I used the wrong form when I re read my >> sentence.
    I even typed dentence then and had to change the d.

    You've got to admit that his pompous lecture, about all the inherent
    defects of one-shots, was amusing.

    John Larkin objects to any post that doesn't flatter him. One that
    points out that he didn't do his home work is even more objectionable.

    I tweaked my phemt one-shot a bit, just for fun. I might even have a
    use for it.

    https://www.dropbox.com/scl/fi/zoncsuiz2ifl30i1tw0cl/Phemt_One-shot_2.jpg?rlkey=z77hx5kkdpijmz5rs7ex63jq7&raw=1

    One cool old circuit that predated ICs was the uni-shot, a single
    transistor and three passives. It was used in model airplane r/c transmitters. One of the three passives was a joystick pot.

    Eccles-Jordan (more correctly Abraham-Bloch) used valves - they predate transistors as well as integrated circuits.

    --
    Bill Sloman, Sydney

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  • From piglet@21:1/5 to John Larkin on Fri May 17 22:11:08 2024
    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:


    One cool old circuit that predated ICs was the uni-shot, a single
    transistor and three passives. It was used in model airplane r/c transmitters. One of the three passives was a joystick pot.


    Uni-shot is unfamiliar to me, I called them “half-shots”. Cascaded as required.

    --
    piglet

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  • From Bill Sloman@21:1/5 to Bill Sloman on Sat May 18 15:58:09 2024
    On 17/05/2024 12:40 am, Bill Sloman wrote:
    On 16/05/2024 11:15 am, John Larkin wrote:
    On Wed, 15 May 2024 22:46:27 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    John Larkin <jjSNIPlarkin@highNONOlandtechnology.com> wrote:

    https://www.dropbox.com/scl/fi/agatzclr8pvr5470g6mc4/Phemt_One_Shot_1.jpg?rlkey=cwnx0qd7ajgnh8otf627x5lku&raw=1

    Regular monostables are terribly slow. This one has low prop delay and >>>> high rep-rate, if the sim is to be believed.

    SAV541 is mostly specified as an RF part, but it's a dynamite switch.

    I can post a link to the files if anybody wants to play with this. All >>>> my values are first guesses, no math involved, and it works!

    My SAV541 Spice model is a revision of Phil Hobbs' original.
    Mini-Circuits is adamant that they will never provide Spice models, a
    typical RF-bigot attitude.



    Yay! Eccles-Jordan ride again.

    1918!

    I think that was a bistable. I don't know when the monostable was >
    invented.

    https://en.wikipedia.org/wiki/Multivibrator

    has a two quotes from 1942 one from 1943 and two from 1949 which make it clear that monostable had been invented by then. It sees it as a cut
    down bistable, so Eccles-Jordan is probably a good name.

    Since the first multivibrator circuit, the astable multivibrator
    oscillator, was invented by Henri Abraham and Eugene Bloch during World
    War I, it probably isn't the right name.

    https://apps.dtic.mil/sti/tr/pdf/AD0410225.pdf

    is a 1963 Ph.D. on the bistable circuit.

    People tend to roll eyes when I use one-shots in logic designs. I
    can't see why.

    You can't trigger a one-shot immediately after it has been triggered,
    and the pulse width you get can be reduced if you re-trigger it too soon after it has generated it's pulse, when it hasn't entirely recovered.

    Using a properly terminated delay line to set the output pulse width
    could reduce this uncertainty, but I've never done it.

    Or rather when I did do it

    Sloman, A.W. and Swords, M.D. "A fast and economical gated
    discriminator", Journal of Physics E: Scientific Instruments, 11,
    521-524 (1978).

    I didn't do it to get a more stable delay but rather because I needed
    narrower pulses than I could get out of any monostable I could buy at
    the time. As the paper notes, the MC10198 could have delivered, but it
    wasn't available when I was putting the circuit together.

    One of the delay lines I used - 350 mm of 50R coaxial cable, or 1.6nsec
    - would have been too short for even the MC10198 - but the rest (5nsec,
    10nsec, 20nsec and 100nsec were lumped constant thick film hybrids)
    could have been replaced.
    Ghiggino, K.P., Phillips, D., and Sloman, A.W. "Nanosecond pulse stretcher",Journal of Physics E: Scientific Instruments, 12, 686-687
    (1979).

    just used two 5GHz wide-band transistors (BFT95) and was perfectly
    horrible, but it did what Dave Phillips and Ken Ghiggino had wanted me
    to give them, and Ken Ghiggino wrote it up rather badly, but I was able
    to rework the short paper into a form that was publishable and looks
    nice on Ken's CV.

    The fact the laser pulses it was designed to detect arrived at a steady
    20MHz meant that it's worst defect didn't matter.

    The 5GHz BFT95 was pretty new when I used it, and I got told about it by
    one of the microwave guys at EMI. The Sloman and Swords paper preceded
    the time I could get that kind of advice.

    The 2n918 I did use in the 1978 paper was only good for 600MHz.

    --
    Bill Sloman, Sydney

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