• Ultra-Low Power Operation

    From Cursitor Doom@21:1/5 to All on Sun Oct 6 09:19:01 2024
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working
    radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone
    know?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From piglet@21:1/5 to Cursitor Doom on Sun Oct 6 09:25:47 2024
    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working
    radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone
    know?


    Around that time there were published designs using germanium transistor inverter to step up 250-300mV to a few volts for driving more conventional items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but
    once started can continue stepping up from much lower voltages. LT made a
    boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV
    booster which lights a LED.


    --
    piglet

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to erichpwagner@hotmail.com on Sun Oct 6 13:28:46 2024
    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a
    competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working
    radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone
    know?


    Around that time there were published designs using germanium transistor >inverter to step up 250-300mV to a few volts for driving more conventional >items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >once started can continue stepping up from much lower voltages. LT made a >boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV >booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all
    designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to All on Sun Oct 6 07:35:24 2024
    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a
    competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working
    radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone
    know?


    Around that time there were published designs using germanium transistor >>inverter to step up 250-300mV to a few volts for driving more conventional >>items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>once started can continue stepping up from much lower voltages. LT made a >>boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV >>booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all >designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    Crystal sets need no power.

    There were some that rectified power from several stations to amplify
    one.

    And yes, a depletion fet or one of the zero-threshold fets could
    detect and amplify at very low supply voltage.

    Where can you buy a half volt battery?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Clive Arthur@21:1/5 to john larkin on Sun Oct 6 16:30:16 2024
    On 06/10/2024 15:35, john larkin wrote:
    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a >>>> competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working >>>> radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone >>>> know?


    Around that time there were published designs using germanium transistor >>> inverter to step up 250-300mV to a few volts for driving more conventional >>> items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>> once started can continue stepping up from much lower voltages. LT made a >>> boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV
    booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all
    designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    Crystal sets need no power.

    There were some that rectified power from several stations to amplify
    one.

    And yes, a depletion fet or one of the zero-threshold fets could
    detect and amplify at very low supply voltage.

    Where can you buy a half volt battery?

    A potato battery is around that.

    --
    Cheers
    Clive

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to All on Sun Oct 6 12:41:43 2024
    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a
    competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working
    radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone
    know?


    Around that time there were published designs using germanium transistor >>inverter to step up 250-300mV to a few volts for driving more conventional >>items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>once started can continue stepping up from much lower voltages. LT made a >>boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV >>booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all >designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    You're mixing up low power with low voltage.

    Many RF devices are available today (and were available
    in the past) that operate without a battery.

    Low voltage is energy scavenging territory.
    Google it.

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to john larkin on Sun Oct 6 17:43:47 2024
    On Sun, 06 Oct 2024 07:35:24 -0700, john larkin <JL@gct.com> wrote:

    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a >>>> competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working >>>> radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone >>>> know?


    Around that time there were published designs using germanium transistor >>>inverter to step up 250-300mV to a few volts for driving more conventional >>>items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>>once started can continue stepping up from much lower voltages. LT made a >>>boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV >>>booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all >>designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    Crystal sets need no power.

    Arguable. They don't need batteries, but do need the power of the
    transmitter to produce an output.

    There were some that rectified power from several stations to amplify
    one.

    Really? Good Lord! I've never heard of that; most resourceful!


    And yes, a depletion fet or one of the zero-threshold fets could
    detect and amplify at very low supply voltage.

    Fascinating. Thanks for that. Depletion mode? I'll have to re-acquaint
    myself with that. I normally use enhancement mode FETs for anything
    requiring the preservation of a high Z signal. I'm not even sure what
    the typical application for a depletion mode FET might be.

    Where can you buy a half volt battery?

    You can't buy them, but I have very many of them here, actually. I
    keep forgetting to recharge them. :)

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to All on Sun Oct 6 10:19:52 2024
    On Sun, 06 Oct 2024 17:43:47 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 06 Oct 2024 07:35:24 -0700, john larkin <JL@gct.com> wrote:

    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com> >>wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet >>><erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a >>>>> competition among radio designers (AM in those days) to come up with >>>>> the design which would operate at the lowest possible supply voltage. >>>>> This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working >>>>> radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I >>>>> do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone >>>>> know?


    Around that time there were published designs using germanium transistor >>>>inverter to step up 250-300mV to a few volts for driving more conventional >>>>items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>>>once started can continue stepping up from much lower voltages. LT made a >>>>boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV >>>>booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our >>>junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest! >>>The circuits that were being submitted to the design contest were all >>>designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    Crystal sets need no power.

    Arguable. They don't need batteries, but do need the power of the
    transmitter to produce an output.

    There were some that rectified power from several stations to amplify
    one.

    Really? Good Lord! I've never heard of that; most resourceful!


    And yes, a depletion fet or one of the zero-threshold fets could
    detect and amplify at very low supply voltage.

    Fascinating. Thanks for that. Depletion mode? I'll have to re-acquaint
    myself with that. I normally use enhancement mode FETs for anything
    requiring the preservation of a high Z signal. I'm not even sure what
    the typical application for a depletion mode FET might be.

    Depletion fets are very useful. The Supertex parts are great. I use
    them as current limiters, for driving LEDs or zeners or discharging
    caps.

    They are great as input protectors too. See AoE3 p 361. H+H added the source-source resistor.

    The LND150/250 parts have very repeatable Idss, around 1.6 mA. Jfets
    are all over the place with as much as 10:1 Idss specs.

    Somebody, can't remember who, makes zero-threshold mosfets.


    Where can you buy a half volt battery?

    You can't buy them, but I have very many of them here, actually. I
    keep forgetting to recharge them. :)

    We need a giant class-action lawsuit against people who sell batteries
    that corrode and leak and destroy things.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to legg on Sun Oct 6 18:47:36 2024
    On Sun, 06 Oct 2024 12:41:43 -0400, legg <legg@nospam.magma.ca> wrote:

    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a >>>> competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working >>>> radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone >>>> know?


    Around that time there were published designs using germanium transistor >>>inverter to step up 250-300mV to a few volts for driving more conventional >>>items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>>once started can continue stepping up from much lower voltages. LT made a >>>boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV >>>booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all >>designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    You're mixing up low power with low voltage.

    Am I?? How so?

    Many RF devices are available today (and were available
    in the past) that operate without a battery.

    For instance....?

    Low voltage is energy scavenging territory.
    Google it.

    I don't Google *anything* if it can possibly be avoided.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From piglet@21:1/5 to Cursitor Doom on Sun Oct 6 22:15:27 2024
    Cursitor Doom <cd@notformail.com> wrote:
    On Sun, 06 Oct 2024 07:35:24 -0700, john larkin <JL@gct.com> wrote:


    There were some that rectified power from several stations to amplify
    one.



    Back in the cold war days some surveillance bugs used that technique to
    avoid having to break in to replace power cells! Maybe some still do.

    --
    piglet

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Lasse Langwadt@21:1/5 to john larkin on Mon Oct 7 00:26:01 2024
    On 10/6/24 16:35, john larkin wrote:
    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a >>>> competition among radio designers (AM in those days) to come up with
    the design which would operate at the lowest possible supply voltage.
    This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working >>>> radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I
    do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone >>>> know?


    Around that time there were published designs using germanium transistor >>> inverter to step up 250-300mV to a few volts for driving more conventional >>> items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>> once started can continue stepping up from much lower voltages. LT made a >>> boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV
    booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all
    designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    Crystal sets need no power.

    I remember an ancient popular mechanics that showed one made a coil a
    capacitor and an old razorblade and pencil to make a diode



    There were some that rectified power from several stations to amplify
    one.

    And yes, a depletion fet or one of the zero-threshold fets could
    detect and amplify at very low supply voltage.

    Where can you buy a half volt battery?

    a zinc and a copper nail in a lemon? ;)

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Cursitor Doom@21:1/5 to Lasse Langwadt on Mon Oct 7 00:49:06 2024
    On Mon, 7 Oct 2024 00:26:01 +0200, Lasse Langwadt <llc@fonz.dk> wrote:

    On 10/6/24 16:35, john larkin wrote:
    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a >>>>> competition among radio designers (AM in those days) to come up with >>>>> the design which would operate at the lowest possible supply voltage. >>>>> This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working >>>>> radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I >>>>> do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone >>>>> know?


    Around that time there were published designs using germanium transistor >>>> inverter to step up 250-300mV to a few volts for driving more conventional >>>> items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>>> once started can continue stepping up from much lower voltages. LT made a >>>> boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV >>>> booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all
    designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    Crystal sets need no power.

    I remember an ancient popular mechanics that showed one made a coil a >capacitor and an old razorblade and pencil to make a diode

    There are quite a lot of such combinations you can use. Safety pins,
    lightbulb filaments and copper plated pennies that have been baked for
    example.

    There were some that rectified power from several stations to amplify
    one.

    And yes, a depletion fet or one of the zero-threshold fets could
    detect and amplify at very low supply voltage.

    Where can you buy a half volt battery?

    a zinc and a copper nail in a lemon? ;)

    Again, lots of ways to make batteries. We found all this fascinating
    when we were children, but kids today just don't seem to give a damn
    about it.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill Sloman@21:1/5 to Cursitor Doom on Mon Oct 7 16:23:32 2024
    On 7/10/2024 4:47 am, Cursitor Doom wrote:
    On Sun, 06 Oct 2024 12:41:43 -0400, legg <legg@nospam.magma.ca> wrote:

    On Sun, 06 Oct 2024 13:28:46 +0100, Cursitor Doom <cd@notformail.com>
    wrote:

    On Sun, 6 Oct 2024 09:25:47 -0000 (UTC), piglet
    <erichpwagner@hotmail.com> wrote:

    Cursitor Doom <cd@notformail.com> wrote:
    Gentlemen,

    I vaguely recall going back the best part of 60 years now, there was a >>>>> competition among radio designers (AM in those days) to come up with >>>>> the design which would operate at the lowest possible supply voltage. >>>>> This had arisen, I would guess, as a result of the 'semiconductor
    revolution' and all these designers would compete to develop a working >>>>> radio using ever more absurd Vcc levels. I'm pretty sure someone
    managed to get something credible together that worked off of just
    over 1 volt but can't be sure after all these years and there's
    nothing I could find on the 'net about such a contest, either. But I >>>>> do remember it, for sure.
    I'd just be interested to know what can be done with <1V today. Anyone >>>>> know?


    Around that time there were published designs using germanium transistor >>>> inverter to step up 250-300mV to a few volts for driving more conventional >>>> items.

    Complete radios built from Ge tunnel diodes were done too.

    Silicon bipolars are constrained by 0.6/0.7V forward junction voltages but >>>> once started can continue stepping up from much lower voltages. LT made a >>>> boost converter IC that once started continued boosting from 100mV.

    Depletion fets let you go much lower, Jan Panteltje has posted his 20mV >>>> booster which lights a LED.

    I take your point, Piglet, but many of us still have Ge devices in our
    junk boxes, so need not be constrained by the greater barrier height
    of their Si equivalents.
    Using some sort of boost converter is not in the spirit of this quest!
    The circuits that were being submitted to the design contest were all
    designed to operate straight from very low DC supplies, with none of
    the shenanigans you mentioned. :)
    This might be a tall order, but I'd like to see a circuit for an AM
    radio which could be powered from half a volt.

    You're mixing up low power with low voltage.

    Am I?? How so?

    Your subject line says "low power" and your content talks only about low voltage operation. You explicitly reject the energy scavenging approach
    that uses inverters to boost low voltage sources up a voltages that can
    operate a silicon transistor.

    Many RF devices are available today (and were available
    in the past) that operate without a battery.

    For instance....?

    Low voltage is energy scavenging territory.
    Google it.

    I don't Google *anything* if it can possibly be avoided.

    If you read any of the electronic trade journals you wouldn't need to
    google it. You don't, and using google would rub your nose in the fact
    that you ought to, if you are posting here.

    In reality you prefer to waste your time on sources that supply the
    lying misinformation that makes you happy - like Zero Hedge and Russia
    Today.

    --
    Bill Sloman, Sydney

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  • From Jan Panteltje@21:1/5 to cd@notformail.com on Mon Oct 7 07:38:39 2024
    On a sunny day (Mon, 07 Oct 2024 00:49:06 +0100) it happened Cursitor Doom <cd@notformail.com> wrote in <2986gjp50ja0hqo7nd3b4tgfd1m7s7ectp@4ax.com>:

    On Mon, 7 Oct 2024 00:26:01 +0200, Lasse Langwadt <llc@fonz.dk> wrote:

    Where can you buy a half volt battery?

    a zinc and a copper nail in a lemon? ;)

    Again, lots of ways to make batteries. We found all this fascinating
    when we were children, but kids today just don't seem to give a damn
    about it.

    You can use a Pleltier module and heat it up with body heat to get low voltages..
    Or power it and use it to cool something:
    https://www.ebay.com/itm/404626611006
    https://www.ebay.com/b/Peltier-Coolers/182022/bn_16565367

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  • From Lasse Langwadt@21:1/5 to Jan Panteltje on Mon Oct 7 22:44:30 2024
    On 10/7/24 09:38, Jan Panteltje wrote:
    On a sunny day (Mon, 07 Oct 2024 00:49:06 +0100) it happened Cursitor Doom <cd@notformail.com> wrote in <2986gjp50ja0hqo7nd3b4tgfd1m7s7ectp@4ax.com>:

    On Mon, 7 Oct 2024 00:26:01 +0200, Lasse Langwadt <llc@fonz.dk> wrote:

    Where can you buy a half volt battery?

    a zinc and a copper nail in a lemon? ;)

    Again, lots of ways to make batteries. We found all this fascinating
    when we were children, but kids today just don't seem to give a damn
    about it.

    You can use a Pleltier module and heat it up with body heat to get low voltages..
    Or power it and use it to cool something:
    https://www.ebay.com/itm/404626611006
    https://www.ebay.com/b/Peltier-Coolers/182022/bn_16565367

    or thermocouples, but you need quite a few in series to get 500mV

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  • From KevinJ93@21:1/5 to john larkin on Tue Oct 8 14:35:05 2024
    On 10/6/24 10:19 AM, john larkin wrote:
    <...>

    Somebody, can't remember who, makes zero-threshold mosfets.

    <...>

    https://www.aldinc.com/ald_zerothresh.php

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