• Replacing mechanical Latching Relays with dual coil relays...

    From John Robertson@21:1/5 to All on Mon Aug 26 10:52:55 2024
    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had trouble
    with some relays going to an indeterminate state if the power to the
    coil is below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset
    coils to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted they
    can't be saved and Guardian hasn't made this coil assy for decades. They
    don't turn up on eBay either.

    Thanks,

    John :-#)#
    --
    (Please post followups or tech inquiries to the USENET newsgroup)
    John's Jukes Ltd.
    #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
    (604)872-5757 (Pinballs, Jukes, Video Games)
    www.flippers.com
    "Old pinballers never die, they just flip out."

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  • From John Robertson@21:1/5 to All on Mon Aug 26 13:12:22 2024
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    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to John Robertson on Mon Aug 26 14:09:26 2024
    On 8/26/2024 10:52 AM, John Robertson wrote:
    Anyone have experience with dual coil latching relays? I'm trying to replace old (1950s) Guardian latch relays as used in 1950s style jukeboxes with more modern two coil latching relays but have had trouble with some relays going to
    an indeterminate state if the power to the coil is  below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset coils
    to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage thread and
    I'm wondering if the Zener diode across the windings or in series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted they can't be saved and Guardian hasn't made this coil assy for decades. They don't turn up on eBay either.

    You're not trying to be "genuine"... so, why dot replace the relay with
    a hybrid *circuit* that emulates a latching relay?

    [No idea what yours are like; I used to encounter them in pin setters
    ("ten pin") -- two coils mounted on a frame at right angles to each
    other. Each coil being a DPDT relay with their armatures mechanically interlocked. Nothing to prevent you from energizing BOTH coils except
    the actual design]

    Depending on the number (and form) of the contacts being used, you
    could design a little SR latch on a board, driving a single relay
    (to give you volt-free contacts) with the appropriate number (and
    form) of contacts.

    One possible complication would be if these were used to maintain state
    in a nonvolatile manner -- adding that to your circuit would require
    a nonvolatile store.

    Of course, the "easy" way is a tiny 6 pin MCU with a FET driving the
    relay... persistent state could be maintained in FLASH.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Robertson@21:1/5 to All on Mon Aug 26 15:12:59 2024
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    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to John Robertson on Mon Aug 26 15:23:45 2024
    On 8/26/2024 3:12 PM, John Robertson wrote:
    Depending on the number (and form) of the contacts being used, you
    could design a little SR latch on a board, driving a single relay
    (to give you volt-free contacts) with the appropriate number (and
    form) of contacts.

    There are two DPDT relays that change state together. 8A non-inductive at 24VDC
    contacts.

    But, one *passively* changes state (its restoring spring is allowed to move
    the armature) while the other actively changes state (its armature moving because of the magnetic force created in the energized coil)

    One possible complication would be if these were used to maintain state
    in a nonvolatile manner -- adding that to your circuit would require
    a nonvolatile store.

    Ah, yes these MUST be non-volatile. The relay must stay set/reset until the mechanical operation resets it, otherwise fuses blow after the gears jam. Power
    interruptions can't change that state...

    <frown>

    Of course, the "easy" way is a tiny 6 pin MCU with a FET driving the
    relay...  persistent state could be maintained in FLASH.

    Now you are just getting fancy! (ducking)

    No, it was just the easiest way to get the nonvolatile support.

    Without the MCU, a cross-coupled NAND (SR latch) could be driven by the
    two "low side" coil controls: pull line A to ground to engage coil A
    and release coil B; pull line B to ground to engage coil B and
    release coil A. A pullup and clamp to V(logic) for each input.
    The output of the latch driving a FET or BJT to energize the
    *4PDT* relay (with two poles wired in the NO configuration and
    the other two in the NC configuration to mimic the two relays
    being in different states).

    If these have to persist in the absence of power (assuming you can
    tolerate the brief delay while the relay reenergizes to resume its
    previous state when power reappears), then you need something that
    will ALWAYS remember.

    You likely don't want to have to put coin cells on each such board
    to preserve the state of the SR latch. The MCU made this a bit easier
    as you could (hopefully) just set aside a piece of FLASH to store
    state (taking into account wear)

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to blockedofcourse@foo.invalid on Mon Aug 26 16:12:53 2024
    On Mon, 26 Aug 2024 14:09:26 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 8/26/2024 10:52 AM, John Robertson wrote:
    Anyone have experience with dual coil latching relays? I'm trying to replace >> old (1950s) Guardian latch relays as used in 1950s style jukeboxes with more >> modern two coil latching relays but have had trouble with some relays going to
    an indeterminate state if the power to the coil is  below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset coils
    to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage thread and
    I'm wondering if the Zener diode across the windings or in series with the >> windings might help my design.

    As for the old original relays, the contacts are getting so pitted they can't
    be saved and Guardian hasn't made this coil assy for decades. They don't turn
    up on eBay either.

    You're not trying to be "genuine"... so, why dot replace the relay with
    a hybrid *circuit* that emulates a latching relay?

    [No idea what yours are like; I used to encounter them in pin setters
    ("ten pin") -- two coils mounted on a frame at right angles to each
    other. Each coil being a DPDT relay with their armatures mechanically >interlocked. Nothing to prevent you from energizing BOTH coils except
    the actual design]

    Depending on the number (and form) of the contacts being used, you
    could design a little SR latch on a board, driving a single relay
    (to give you volt-free contacts) with the appropriate number (and
    form) of contacts.

    One possible complication would be if these were used to maintain state
    in a nonvolatile manner -- adding that to your circuit would require
    a nonvolatile store.

    Of course, the "easy" way is a tiny 6 pin MCU with a FET driving the
    relay... persistent state could be maintained in FLASH.


    A little cmos flipflop circuit and a Tadiran lithium battery or a
    supercap would work too.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Liz Tuddenham@21:1/5 to John Robertson on Tue Aug 27 08:54:11 2024
    John Robertson <jrr@flippers.com> wrote:

    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had trouble
    with some relays going to an indeterminate state if the power to the
    coil is below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset coils to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted they
    can't be saved and Guardian hasn't made this coil assy for decades. They don't turn up on eBay either.

    Two opposed solenoids and an arm on the spindle of a rotary switch.

    --
    ~ Liz Tuddenham ~
    (Remove the ".invalid"s and add ".co.uk" to reply)
    www.poppyrecords.co.uk

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From piglet@21:1/5 to John Robertson on Tue Aug 27 09:44:17 2024
    John Robertson <jrr@flippers.com> wrote:
    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had trouble
    with some relays going to an indeterminate state if the power to the
    coil is below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset coils to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted they
    can't be saved and Guardian hasn't made this coil assy for decades. They don't turn up on eBay either.

    Thanks,

    John :-#)#

    Millions of latching relays are still made. If the problem is under
    voltages causing erratic activity I guess a driver with threshold detection using LM339s or TL431s or whatever might be possible. Either to trigger
    dual coil latch relays or single coil bipolar latch relays.

    Can you give numbers, like correct coil voltage and the troublesome
    incorrect voltages ?

    Something as simple as series SCR with zener anode to gate might be enough?

    --
    piglet

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jasen Betts@21:1/5 to Liz Tuddenham on Tue Aug 27 12:44:25 2024
    On 2024-08-27, Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
    John Robertson <jrr@flippers.com> wrote:

    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had trouble
    with some relays going to an indeterminate state if the power to the
    coil is below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset
    coils to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted they
    can't be saved and Guardian hasn't made this coil assy for decades. They
    don't turn up on eBay either.

    Two opposed solenoids and an arm on the spindle of a rotary switch.

    Or on an bank of opposed microswitches. I've seen that done except
    the solenoide were a telephone ringer hammer driver.

    --
    Jasen.
    🇺🇦 Слава Україні

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to John Robertson on Tue Aug 27 14:02:37 2024
    John Robertson <jrr@flippers.com> wrote:
    On 2024-08-26 2:09 p.m., Don Y wrote:
    On 8/26/2024 10:52 AM, John Robertson wrote:
    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had
    trouble with some relays going to an indeterminate state if the power
    to the coil is  below optimum.

    What I actually need to do is a circuit that only allows the Latch/
    Reset coils to trip when there is sufficient voltage and current
    available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted
    they can't be saved and Guardian hasn't made this coil assy for
    decades. They don't turn up on eBay either.

    You're not trying to be "genuine"... so, why dot replace the relay with
    a hybrid *circuit* that emulates a latching relay?

    [No idea what yours are like; I used to encounter them in pin setters
    ("ten pin") -- two coils mounted on a frame at right angles to each
    other.  Each coil being a DPDT relay with their armatures mechanically
    interlocked.  Nothing to prevent you from energizing BOTH coils except
    the actual design]

    Yes, this sounds the same.


    Depending on the number (and form) of the contacts being used, you
    could design a little SR latch on a board, driving a single relay
    (to give you volt-free contacts) with the appropriate number (and
    form) of contacts.

    There are two DPDT relays that change state together. 8A non-inductive
    at 24VDC contacts.


    One possible complication would be if these were used to maintain state
    in a nonvolatile manner -- adding that to your circuit would require
    a nonvolatile store.

    Ah, yes these MUST be non-volatile. The relay must stay set/reset until
    the mechanical operation resets it, otherwise fuses blow after the gears
    jam. Power interruptions can't change that state...


    Of course, the "easy" way is a tiny 6 pin MCU with a FET driving the
    relay...  persistent state could be maintained in FLASH.

    Now you are just getting fancy! (ducking)

    John :-#(#


    I’d be cautious about any solution that separates the physical state of the switch from the logical state.

    How about a nice small latching relay controlling a triac or SSR? You can
    do the UVLO function with a MAX809 or something like that to gate the
    supply to the relay coil.

    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 Robertson@21:1/5 to piglet on Tue Aug 27 07:06:03 2024
    On 2024-08-27 2:44 a.m., piglet wrote:
    John Robertson <jrr@flippers.com> wrote:
    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had trouble
    with some relays going to an indeterminate state if the power to the
    coil is below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset
    coils to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted they
    can't be saved and Guardian hasn't made this coil assy for decades. They
    don't turn up on eBay either.

    Thanks,

    John :-#)#

    Millions of latching relays are still made. If the problem is under
    voltages causing erratic activity I guess a driver with threshold detection using LM339s or TL431s or whatever might be possible. Either to trigger
    dual coil latch relays or single coil bipolar latch relays.

    The problem is switch noise.


    Can you give numbers, like correct coil voltage and the troublesome
    incorrect voltages ?

    Correct coil voltage is 24VDC.

    Modern latching relays don't have a mechanical interlock - at least I
    haven't seen any - like the original Guardians. So if the microswitch to
    trip the relay is noisy then the modern latch relays go into a middle indeterminate state and then we get jammed gears - blown fuses.


    Something as simple as series SCR with zener anode to gate might be enough?


    Yes, something like that may work, I'll have to post the schematic of a
    typical interlock relay when I have some time. Whatever is figured out
    has to not allow an indeterminate state.

    Thanks!

    John :-#)#



    --
    (Please post followups or tech inquiries to the USENET newsgroup)
    John's Jukes Ltd.
    #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
    (604)872-5757 (Pinballs, Jukes, Video Games)
    www.flippers.com
    "Old pinballers never die, they just flip out."

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to Jasen Betts on Tue Aug 27 14:07:25 2024
    Jasen Betts <usenet@revmaps.no-ip.org> wrote:
    On 2024-08-27, Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
    John Robertson <jrr@flippers.com> wrote:

    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had trouble >>> with some relays going to an indeterminate state if the power to the
    coil is below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset >>> coils to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted they
    can't be saved and Guardian hasn't made this coil assy for decades. They >>> don't turn up on eBay either.

    Two opposed solenoids and an arm on the spindle of a rotary switch.

    Or on an bank of opposed microswitches. I've seen that done except
    the solenoide were a telephone ringer hammer driver.


    The rated lifetime of your average switch is a small fraction of your
    average relay’s, even if you don’t abuse it like that.

    Some microswitches are better, but still not the 1E7 of a good relay iirc.

    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 pcdhSpamMeSenseless@electrooptical. on Tue Aug 27 07:40:21 2024
    On Tue, 27 Aug 2024 14:02:37 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    John Robertson <jrr@flippers.com> wrote:
    On 2024-08-26 2:09 p.m., Don Y wrote:
    On 8/26/2024 10:52 AM, John Robertson wrote:
    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had
    trouble with some relays going to an indeterminate state if the power
    to the coil is  below optimum.

    What I actually need to do is a circuit that only allows the Latch/
    Reset coils to trip when there is sufficient voltage and current
    available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted
    they can't be saved and Guardian hasn't made this coil assy for
    decades. They don't turn up on eBay either.

    You're not trying to be "genuine"... so, why dot replace the relay with
    a hybrid *circuit* that emulates a latching relay?

    [No idea what yours are like; I used to encounter them in pin setters
    ("ten pin") -- two coils mounted on a frame at right angles to each
    other.  Each coil being a DPDT relay with their armatures mechanically
    interlocked.  Nothing to prevent you from energizing BOTH coils except
    the actual design]

    Yes, this sounds the same.


    Depending on the number (and form) of the contacts being used, you
    could design a little SR latch on a board, driving a single relay
    (to give you volt-free contacts) with the appropriate number (and
    form) of contacts.

    There are two DPDT relays that change state together. 8A non-inductive
    at 24VDC contacts.


    One possible complication would be if these were used to maintain state
    in a nonvolatile manner -- adding that to your circuit would require
    a nonvolatile store.

    Ah, yes these MUST be non-volatile. The relay must stay set/reset until
    the mechanical operation resets it, otherwise fuses blow after the gears
    jam. Power interruptions can't change that state...


    Of course, the "easy" way is a tiny 6 pin MCU with a FET driving the
    relay...  persistent state could be maintained in FLASH.

    Now you are just getting fancy! (ducking)

    John :-#(#


    I’d be cautious about any solution that separates the physical state of the >switch from the logical state.

    How about a nice small latching relay controlling a triac or SSR? You can
    do the UVLO function with a MAX809 or something like that to gate the
    supply to the relay coil.

    Or a small latching relay controlling a big ole relay?

    We like the

    FUJITSU FTR-B3GB4.5Z-B10

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Joe Gwinn@21:1/5 to All on Tue Aug 27 11:10:10 2024
    On Tue, 27 Aug 2024 07:06:03 -0700, John Robertson <jrr@flippers.com>
    wrote:

    On 2024-08-27 2:44 a.m., piglet wrote:
    John Robertson <jrr@flippers.com> wrote:
    Anyone have experience with dual coil latching relays? I'm trying to
    replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had trouble >>> with some relays going to an indeterminate state if the power to the
    coil is below optimum.

    What I actually need to do is a circuit that only allows the Latch/Reset >>> coils to trip when there is sufficient voltage and current available...

    This somewhat plays into the discussion on DC relay latching voltage
    thread and I'm wondering if the Zener diode across the windings or in
    series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted they
    can't be saved and Guardian hasn't made this coil assy for decades. They >>> don't turn up on eBay either.

    Thanks,

    John :-#)#

    Millions of latching relays are still made. If the problem is under
    voltages causing erratic activity I guess a driver with threshold detection >> using LM339s or TL431s or whatever might be possible. Either to trigger
    dual coil latch relays or single coil bipolar latch relays.

    The problem is switch noise.


    Can you give numbers, like correct coil voltage and the troublesome
    incorrect voltages ?

    Correct coil voltage is 24VDC.

    Modern latching relays don't have a mechanical interlock - at least I
    haven't seen any - like the original Guardians. So if the microswitch to
    trip the relay is noisy then the modern latch relays go into a middle >indeterminate state and then we get jammed gears - blown fuses.


    Something as simple as series SCR with zener anode to gate might be enough? >>

    Yes, something like that may work, I'll have to post the schematic of a >typical interlock relay when I have some time. Whatever is figured out
    has to not allow an indeterminate state.

    There is a large literature on electronic designs for interlocking safety-critical functions, like firing a rocket or detonating a bomb.
    This literature can be a source of circuit ideas and hazards to be
    addressed.

    Joe Gwinn

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From John Robertson@21:1/5 to All on Tue Aug 27 10:34:15 2024
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    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to All on Tue Aug 27 13:02:21 2024
    On Tue, 27 Aug 2024 10:34:15 -0700, John Robertson <jrr@flippers.com>
    wrote:

    On 2024-08-27 7:40 a.m., john larkin wrote:
    On Tue, 27 Aug 2024 14:02:37 -0000 (UTC), Phil Hobbs
    <pcdhSpamMeSenseless@electrooptical.net> wrote:

    John Robertson <jrr@flippers.com> wrote:
    On 2024-08-26 2:09 p.m., Don Y wrote:
    On 8/26/2024 10:52 AM, John Robertson wrote:
    Anyone have experience with dual coil latching relays? I'm trying to >>>>>> replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had
    trouble with some relays going to an indeterminate state if the power >>>>>> to the coil is  below optimum.

    What I actually need to do is a circuit that only allows the Latch/ >>>>>> Reset coils to trip when there is sufficient voltage and current
    available...

    This somewhat plays into the discussion on DC relay latching voltage >>>>>> thread and I'm wondering if the Zener diode across the windings or in >>>>>> series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted >>>>>> they can't be saved and Guardian hasn't made this coil assy for
    decades. They don't turn up on eBay either.

    You're not trying to be "genuine"... so, why dot replace the relay with >>>>> a hybrid *circuit* that emulates a latching relay?

    [No idea what yours are like; I used to encounter them in pin setters >>>>> ("ten pin") -- two coils mounted on a frame at right angles to each
    other.  Each coil being a DPDT relay with their armatures mechanically >>>>> interlocked.  Nothing to prevent you from energizing BOTH coils except >>>>> the actual design]

    Yes, this sounds the same.


    Depending on the number (and form) of the contacts being used, you
    could design a little SR latch on a board, driving a single relay
    (to give you volt-free contacts) with the appropriate number (and
    form) of contacts.

    There are two DPDT relays that change state together. 8A non-inductive >>>> at 24VDC contacts.


    One possible complication would be if these were used to maintain state >>>>> in a nonvolatile manner -- adding that to your circuit would require >>>>> a nonvolatile store.

    Ah, yes these MUST be non-volatile. The relay must stay set/reset until >>>> the mechanical operation resets it, otherwise fuses blow after the gears >>>> jam. Power interruptions can't change that state...


    Of course, the "easy" way is a tiny 6 pin MCU with a FET driving the >>>>> relay...  persistent state could be maintained in FLASH.

    Now you are just getting fancy! (ducking)

    John :-#(#


    I’d be cautious about any solution that separates the physical state of the >>> switch from the logical state.

    How about a nice small latching relay controlling a triac or SSR? You can >>> do the UVLO function with a MAX809 or something like that to gate the
    supply to the relay coil.

    Or a small latching relay controlling a big ole relay?

    We like the

    FUJITSU FTR-B3GB4.5Z-B10


    Interesting that you reverse the coil polarity to release the single coil.


    We use a fiendishly clever dual NOR gate circuit to drive these. It
    takes basically one wire per relay from our uP or FPGA.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to All on Wed Aug 28 08:28:49 2024
    On Tue, 27 Aug 2024 10:34:15 -0700, John Robertson <jrr@flippers.com>
    wrote:

    On 2024-08-27 7:40 a.m., john larkin wrote:
    On Tue, 27 Aug 2024 14:02:37 -0000 (UTC), Phil Hobbs
    <pcdhSpamMeSenseless@electrooptical.net> wrote:

    John Robertson <jrr@flippers.com> wrote:
    On 2024-08-26 2:09 p.m., Don Y wrote:
    On 8/26/2024 10:52 AM, John Robertson wrote:
    Anyone have experience with dual coil latching relays? I'm trying to >>>>>> replace old (1950s) Guardian latch relays as used in 1950s style
    jukeboxes with more modern two coil latching relays but have had
    trouble with some relays going to an indeterminate state if the power >>>>>> to the coil is  below optimum.

    What I actually need to do is a circuit that only allows the Latch/ >>>>>> Reset coils to trip when there is sufficient voltage and current
    available...

    This somewhat plays into the discussion on DC relay latching voltage >>>>>> thread and I'm wondering if the Zener diode across the windings or in >>>>>> series with the windings might help my design.

    As for the old original relays, the contacts are getting so pitted >>>>>> they can't be saved and Guardian hasn't made this coil assy for
    decades. They don't turn up on eBay either.

    You're not trying to be "genuine"... so, why dot replace the relay with >>>>> a hybrid *circuit* that emulates a latching relay?

    [No idea what yours are like; I used to encounter them in pin setters >>>>> ("ten pin") -- two coils mounted on a frame at right angles to each
    other.  Each coil being a DPDT relay with their armatures mechanically >>>>> interlocked.  Nothing to prevent you from energizing BOTH coils except >>>>> the actual design]

    Yes, this sounds the same.


    Depending on the number (and form) of the contacts being used, you
    could design a little SR latch on a board, driving a single relay
    (to give you volt-free contacts) with the appropriate number (and
    form) of contacts.

    There are two DPDT relays that change state together. 8A non-inductive >>>> at 24VDC contacts.


    One possible complication would be if these were used to maintain state >>>>> in a nonvolatile manner -- adding that to your circuit would require >>>>> a nonvolatile store.

    Ah, yes these MUST be non-volatile. The relay must stay set/reset until >>>> the mechanical operation resets it, otherwise fuses blow after the gears >>>> jam. Power interruptions can't change that state...


    Of course, the "easy" way is a tiny 6 pin MCU with a FET driving the >>>>> relay...  persistent state could be maintained in FLASH.

    Now you are just getting fancy! (ducking)

    John :-#(#


    I’d be cautious about any solution that separates the physical state of the >>> switch from the logical state.

    How about a nice small latching relay controlling a triac or SSR? You can >>> do the UVLO function with a MAX809 or something like that to gate the
    supply to the relay coil.

    Or a small latching relay controlling a big ole relay?

    We like the

    FUJITSU FTR-B3GB4.5Z-B10


    Interesting that you reverse the coil polarity to release the single coil.

    Gives me other ideas on solving the problem - use a small (2A contacts)
    dual coil latching relay to drive a bigger relay. The small relay won't
    be bothered as much by switch noise as the current required is much less
    so is unlikely to get into an illegal state. Will read the product
    literature on these and see what comes up as a good unit.

    Like I don't have enough projects!

    John :-#)#

    Depends on whether simply 'remembering' last state is as
    good as holding it, during power loss.

    RL

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  • From David Lesher@21:1/5 to John Robertson on Thu Dec 5 00:16:08 2024
    John Robertson <jrr@flippers.com> writes:

    T24gMjAyNC0wOC0yNyA3OjQwIGEubS4sIGpvaG4gbGFya2luIHdyb3RlOg0KPiBPbiBUdWUs >IDI3IEF1ZyAyMDI0IDE0OjAyOjM3IC0wMDAwIChVVEMpLCBQaGlsIEhvYmJzDQo+IDxwY2Ro

    What's with this dreck?

    --
    A host is a host from coast to coast...............wb8foz@panix.com
    & no one will talk to a host that's close..........................
    Unless the host (that isn't close).........................pob 1433
    is busy, hung or dead....................................20915-1433

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  • From Don Y@21:1/5 to David Lesher on Fri Dec 6 00:51:19 2024
    On 12/4/2024 5:16 PM, David Lesher wrote:
    John Robertson <jrr@flippers.com> writes:

    T24gMjAyNC0wOC0yNyA3OjQwIGEubS4sIGpvaG4gbGFya2luIHdyb3RlOg0KPiBPbiBUdWUs
    IDI3IEF1ZyAyMDI0IDE0OjAyOjM3IC0wMDAwIChVVEMpLCBQaGlsIEhvYmJzDQo+IDxwY2Ro

    What's with this dreck?

    It doesn't appear in any of the upstream posts that I'm seeing.
    Though I don't always see everything that is posted...

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  • From John Robertson@21:1/5 to David Lesher on Mon Dec 9 17:21:23 2024
    On 2024-12-04 4:16 p.m., David Lesher wrote:
    John Robertson <jrr@flippers.com> writes:

    T24gMjAyNC0wOC0yNyA3OjQwIGEubS4sIGpvaG4gbGFya2luIHdyb3RlOg0KPiBPbiBUdWUs
    IDI3IEF1ZyAyMDI0IDE0OjAyOjM3IC0wMDAwIChVVEMpLCBQaGlsIEhvYmJzDQo+IDxwY2Ro

    What's with this dreck?


    No one else has commented on that bad data stream - I suspect your news
    host garbled it. E-S sometimes jumbles messages together I find, as an
    example

    Enough people here would have mentioned if it was an actual post.

    John :-#)#

    --
    (Please post followups or tech inquiries to the USENET newsgroup)
    John's Jukes Ltd.
    #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
    (604)872-5757 (Pinballs, Jukes, Video Games)
    www.flippers.com
    "Old pinballers never die, they just flip out."

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