D
Don Y
Guest
On 5/31/2023 7:32 PM, Ed Lee wrote:
Again, you\'ve managed NOT to answer the question...
Again, you\'ve managed NOT to answer the question...
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E
Ed Lee
Guest
On Wednesday, May 31, 2023 at 8:06:12â¯PM UTC-7, Don Y wrote:
I thought I did. They are in different capacities and can\'t just permanently be in series.
On 5/31/2023 7:32 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 7:26:19â¯PM UTC-7, Don Y wrote:
On 5/31/2023 6:56 PM, Ed Lee wrote:
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Saying so LITTLE -- yet wanting such a switch -- suggests you
want to treat the 8 cells as *individually* \"0V referenced\"
(perhaps for a 48V charger?) and then STACK them in series
(throwing a switch) to develop the 384VDC.
I.e., why aren\'t you just wiring them in series permanently?
They are in different capacities and state of charge, and total voltage vary between 384V and 408V. Changing voltage allows them to discharge deeper. It\'s deeper cycle batteries.
Again, you\'ve managed NOT to answer the question...
I thought I did. They are in different capacities and can\'t just permanently be in series.
D
Don Y
Guest
On 5/31/2023 9:08 PM, Ed Lee wrote:
So, what does the *switch* do? (this defines the constraints placed
on the switch selection!)
On Wednesday, May 31, 2023 at 8:06:12â¯PM UTC-7, Don Y wrote:
On 5/31/2023 7:32 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 7:26:19â¯PM UTC-7, Don Y wrote:
On 5/31/2023 6:56 PM, Ed Lee wrote:
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Saying so LITTLE -- yet wanting such a switch -- suggests you
want to treat the 8 cells as *individually* \"0V referenced\"
(perhaps for a 48V charger?) and then STACK them in series
(throwing a switch) to develop the 384VDC.
I.e., why aren\'t you just wiring them in series permanently?
They are in different capacities and state of charge, and total voltage vary between 384V and 408V. Changing voltage allows them to discharge deeper. It\'s deeper cycle batteries.
Again, you\'ve managed NOT to answer the question...
I thought I did. They are in different capacities and can\'t just permanently be in series.
So, what does the *switch* do? (this defines the constraints placed
on the switch selection!)
R
Ricky
Guest
On Wednesday, May 31, 2023 at 9:56:41â¯PM UTC-4, Ed Lee wrote:
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
--
Rick C.
-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209
On Wednesday, May 31, 2023 at 5:43:46â¯PM UTC-7, Don Y wrote:
On 5/31/2023 4:41 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 3:25:18â¯PM UTC-7, Don Y wrote:
On 5/31/2023 8:02 AM, Ed Lee wrote:
Someone suggested mercury switches.
Ordered some to try out:
https://www.ebay.com/itm/195708179355?var=495574245862
No. Mercury *wetted* switches/relays/contactors. The switch contacts
are coated witha bit of mercury that allows the connection to be
maintained AS the switch would otherwise be bouncing; it \"snaps\"
open/closed more cleanly.
https://www.ebay.com/itm/155576690745
https://www.ebay.com/itm/134585850699
https://www.ebay.com/itm/155535895796
Selecting the proper \"switch\" will depend on your application and
the faults you are likely to encounter *or* that must be guarded
against.
You may have to augment the \"switch\" with other circuitry to
guard against things like welded contacts -- if such an event
can \"cause a problem/loss\".
Or, may choose to use different technologies to address
different aspects of your particular problem.
[E.g., UPSs have a mechanical shorting bar that can be removed
to isolate the battery; far more reliable than the relays inside!]
Yes, i am thinking about using mercury switches for lock box door. When the user flip up the door to access the function switch, it should disconnect the power source first.
(again, without knowing your application...) You can treat the \"door\"
as an armature and have it\'s opening *break* the contacts formed
by simply mating connectors (the traveling connector on the door
with the stationary one on the box)
Also got couple of ex-soviet military surplus heavy duty 16P2T switches. But probably hard to find any more. It can switch 8 independent power sources upto 3A.
https://www.ebay.com/itm/353292464636
Ex-soviet is good for something.
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
--
Rick C.
-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209
E
Ed Lee
Guest
On Thursday, June 1, 2023 at 1:32:18â¯AM UTC-7, Ricky wrote:
Firstly, my cells are between 100 to 2000 Whr, 12V and 16V. Eventually, they should all be 2000, but I don\'t have enough yet. I only have 3 16V 2000Wh cells so far. Eventually, there will be 24 16V 2000Wh. Until then, I mix them with groups of 12V 100 and 200 Whr cells. So, I need to switch the lower capacities in and out of the chain. Right now, i am doing it manually and trip the circuit breaker often. No big deal, but toggle switches should minimize chance of mismatches.
Secondly, I switch a 12V cell between the 12V and 384V chains. During charging, the 12V cell is charged separately. After couple of miles of driving, the 12V cell is switch back into the 384V chain. This way, the expansion cells are cycled deeper than the main battery.
Thirdly, there are other prototype configurations. I guess I am driving my prototype lab around all the time.
On Wednesday, May 31, 2023 at 9:56:41â¯PM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 5:43:46â¯PM UTC-7, Don Y wrote:
On 5/31/2023 4:41 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 3:25:18â¯PM UTC-7, Don Y wrote:
On 5/31/2023 8:02 AM, Ed Lee wrote:
Someone suggested mercury switches.
Ordered some to try out:
https://www.ebay.com/itm/195708179355?var=495574245862
No. Mercury *wetted* switches/relays/contactors. The switch contacts
are coated witha bit of mercury that allows the connection to be
maintained AS the switch would otherwise be bouncing; it \"snaps\"
open/closed more cleanly.
https://www.ebay.com/itm/155576690745
https://www.ebay.com/itm/134585850699
https://www.ebay.com/itm/155535895796
Selecting the proper \"switch\" will depend on your application and
the faults you are likely to encounter *or* that must be guarded
against.
You may have to augment the \"switch\" with other circuitry to
guard against things like welded contacts -- if such an event
can \"cause a problem/loss\".
Or, may choose to use different technologies to address
different aspects of your particular problem.
[E.g., UPSs have a mechanical shorting bar that can be removed
to isolate the battery; far more reliable than the relays inside!]
Yes, i am thinking about using mercury switches for lock box door. When the user flip up the door to access the function switch, it should disconnect the power source first.
(again, without knowing your application...) You can treat the \"door\"
as an armature and have it\'s opening *break* the contacts formed
by simply mating connectors (the traveling connector on the door
with the stationary one on the box)
Also got couple of ex-soviet military surplus heavy duty 16P2T switches. But probably hard to find any more. It can switch 8 independent power sources upto 3A.
https://www.ebay.com/itm/353292464636
Ex-soviet is good for something.
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
Firstly, my cells are between 100 to 2000 Whr, 12V and 16V. Eventually, they should all be 2000, but I don\'t have enough yet. I only have 3 16V 2000Wh cells so far. Eventually, there will be 24 16V 2000Wh. Until then, I mix them with groups of 12V 100 and 200 Whr cells. So, I need to switch the lower capacities in and out of the chain. Right now, i am doing it manually and trip the circuit breaker often. No big deal, but toggle switches should minimize chance of mismatches.
Secondly, I switch a 12V cell between the 12V and 384V chains. During charging, the 12V cell is charged separately. After couple of miles of driving, the 12V cell is switch back into the 384V chain. This way, the expansion cells are cycled deeper than the main battery.
Thirdly, there are other prototype configurations. I guess I am driving my prototype lab around all the time.
J
John Larkin
Guest
On Tue, 30 May 2023 00:42:15 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:
Wow, 43 posts on the subject, mostly speculation.
Doesn\'t anybody have a switch and an oscilloscope?
https://quotefancy.com/media/wallpaper/3840x2160/859595-Wernher-von-Braun-Quote-One-good-test-is-worth-a-thousand-expert.jpg
<edward.ming.lee@gmail.com> wrote:
Anybody got access to this article:
https://pubmed.ncbi.nlm.nih.gov/18999467
regarding switch time of such switch:
https://www.ebay.com/itm/284624886322
Or simply a guess? 1/5 to 1/3 second?
Wow, 43 posts on the subject, mostly speculation.
Doesn\'t anybody have a switch and an oscilloscope?
https://quotefancy.com/media/wallpaper/3840x2160/859595-Wernher-von-Braun-Quote-One-good-test-is-worth-a-thousand-expert.jpg
E
Ed Lee
Guest
On Thursday, June 1, 2023 at 7:06:02â¯AM UTC-7, John Larkin wrote:
I don\'t have a scope handy.
I can send you the switch and you can tell us with your scope.
We want to know switching time for 12V and 16V.
On Tue, 30 May 2023 00:42:15 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
Anybody got access to this article:
https://pubmed.ncbi.nlm.nih.gov/18999467
regarding switch time of such switch:
https://www.ebay.com/itm/284624886322
Or simply a guess? 1/5 to 1/3 second?
Wow, 43 posts on the subject, mostly speculation.
Doesn\'t anybody have a switch and an oscilloscope?
https://quotefancy.com/media/wallpaper/3840x2160/859595-Wernher-von-Braun-Quote-One-good-test-is-worth-a-thousand-expert.jpg
I don\'t have a scope handy.
I can send you the switch and you can tell us with your scope.
We want to know switching time for 12V and 16V.
J
John Larkin
Guest
On Thu, 1 Jun 2023 07:12:45 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:
The little LCD scopes from ebay or amazon are pretty good, around $30.
You could get one of those for about what it would cost to ship me a
switch.
https://www.amazon.com/Digital-Oscilloscope-Portable-Sampling-Oscilloscopes/dp/B0BXD6JL8T/ref=sr_1_7_sspa?crid=1T98ZXGBI76PL&keywords=lcd+oscilloscope&qid=1685634469&sprefix=lcd+oscill%2Caps%2C161&sr=8-7-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTDVGT0xZVlo0TTlKJmVuY3J5cHRlZElkPUEwODM0Nzk3M0I5T1oyTVRJVTc4SyZlbmNyeXB0ZWRBZElkPUExMDM5OTQ2SkRPQTVPR0RRWllXJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
Then you would have a scope.
<edward.ming.lee@gmail.com> wrote:
On Thursday, June 1, 2023 at 7:06:02?AM UTC-7, John Larkin wrote:
On Tue, 30 May 2023 00:42:15 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
Anybody got access to this article:
https://pubmed.ncbi.nlm.nih.gov/18999467
regarding switch time of such switch:
https://www.ebay.com/itm/284624886322
Or simply a guess? 1/5 to 1/3 second?
Wow, 43 posts on the subject, mostly speculation.
Doesn\'t anybody have a switch and an oscilloscope?
https://quotefancy.com/media/wallpaper/3840x2160/859595-Wernher-von-Braun-Quote-One-good-test-is-worth-a-thousand-expert.jpg
I don\'t have a scope handy.
I can send you the switch and you can tell us with your scope.
We want to know switching time for 12V and 16V.
The little LCD scopes from ebay or amazon are pretty good, around $30.
You could get one of those for about what it would cost to ship me a
switch.
https://www.amazon.com/Digital-Oscilloscope-Portable-Sampling-Oscilloscopes/dp/B0BXD6JL8T/ref=sr_1_7_sspa?crid=1T98ZXGBI76PL&keywords=lcd+oscilloscope&qid=1685634469&sprefix=lcd+oscill%2Caps%2C161&sr=8-7-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTDVGT0xZVlo0TTlKJmVuY3J5cHRlZElkPUEwODM0Nzk3M0I5T1oyTVRJVTc4SyZlbmNyeXB0ZWRBZElkPUExMDM5OTQ2SkRPQTVPR0RRWllXJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
Then you would have a scope.
E
Ed Lee
Guest
On Thursday, June 1, 2023 at 8:51:56â¯AM UTC-7, John Larkin wrote:
OK, i\'ll try it. I also sent a request to the manufacturer to do it. Let see if they will response.
On Thu, 1 Jun 2023 07:12:45 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, June 1, 2023 at 7:06:02?AM UTC-7, John Larkin wrote:
On Tue, 30 May 2023 00:42:15 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
Anybody got access to this article:
https://pubmed.ncbi.nlm.nih.gov/18999467
regarding switch time of such switch:
https://www.ebay.com/itm/284624886322
Or simply a guess? 1/5 to 1/3 second?
Wow, 43 posts on the subject, mostly speculation.
Doesn\'t anybody have a switch and an oscilloscope?
https://quotefancy.com/media/wallpaper/3840x2160/859595-Wernher-von-Braun-Quote-One-good-test-is-worth-a-thousand-expert.jpg
I don\'t have a scope handy.
I can send you the switch and you can tell us with your scope.
We want to know switching time for 12V and 16V.
The little LCD scopes from ebay or amazon are pretty good, around $30.
You could get one of those for about what it would cost to ship me a
switch.
https://www.amazon.com/Digital-Oscilloscope-Portable-Sampling-Oscilloscopes/dp/B0BXD6JL8T/ref=sr_1_7_sspa?crid=1T98ZXGBI76PL&keywords=lcd+oscilloscope&qid=1685634469&sprefix=lcd+oscill%2Caps%2C161&sr=8-7-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTDVGT0xZVlo0TTlKJmVuY3J5cHRlZElkPUEwODM0Nzk3M0I5T1oyTVRJVTc4SyZlbmNyeXB0ZWRBZElkPUExMDM5OTQ2SkRPQTVPR0RRWllXJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
Then you would have a scope.
OK, i\'ll try it. I also sent a request to the manufacturer to do it. Let see if they will response.
E
ehsjr
Guest
On 6/1/2023 9:50 AM, Ed Lee wrote:
...................SW1
----384Vchain----O-->O---+--chain continued
..........................|Z
..................O--12V--+
Ignore the periods - they are just placeholders
to make the ASCII spacing right.
Ok - that prevents shorting. If you need to totally
isolate the 12V from the chain, replace the connection
next to Z with another switch or a second set of contacts.
Using ASCII, draw what ever issue that leaves unsolved.
Trying to follow the concept you have in mind without
a schematic has apparently caused confusion.
Ed
On Thursday, June 1, 2023 at 1:32:18â¯AM UTC-7, Ricky wrote:
On Wednesday, May 31, 2023 at 9:56:41â¯PM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 5:43:46â¯PM UTC-7, Don Y wrote:
On 5/31/2023 4:41 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 3:25:18â¯PM UTC-7, Don Y wrote:
On 5/31/2023 8:02 AM, Ed Lee wrote:
Someone suggested mercury switches.
Ordered some to try out:
https://www.ebay.com/itm/195708179355?var=495574245862
No. Mercury *wetted* switches/relays/contactors. The switch contacts
are coated witha bit of mercury that allows the connection to be
maintained AS the switch would otherwise be bouncing; it \"snaps\"
open/closed more cleanly.
https://www.ebay.com/itm/155576690745
https://www.ebay.com/itm/134585850699
https://www.ebay.com/itm/155535895796
Selecting the proper \"switch\" will depend on your application and
the faults you are likely to encounter *or* that must be guarded
against.
You may have to augment the \"switch\" with other circuitry to
guard against things like welded contacts -- if such an event
can \"cause a problem/loss\".
Or, may choose to use different technologies to address
different aspects of your particular problem.
[E.g., UPSs have a mechanical shorting bar that can be removed
to isolate the battery; far more reliable than the relays inside!]
Yes, i am thinking about using mercury switches for lock box door. When the user flip up the door to access the function switch, it should disconnect the power source first.
(again, without knowing your application...) You can treat the \"door\"
as an armature and have it\'s opening *break* the contacts formed
by simply mating connectors (the traveling connector on the door
with the stationary one on the box)
Also got couple of ex-soviet military surplus heavy duty 16P2T switches. But probably hard to find any more. It can switch 8 independent power sources upto 3A.
https://www.ebay.com/itm/353292464636
Ex-soviet is good for something.
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
Firstly, my cells are between 100 to 2000 Whr, 12V and 16V. Eventually, they should all be 2000, but I don\'t have enough yet. I only have 3 16V 2000Wh cells so far. Eventually, there will be 24 16V 2000Wh. Until then, I mix them with groups of 12V 100 and 200 Whr cells. So, I need to switch the lower capacities in and out of the chain. Right now, i am doing it manually and trip the circuit breaker often. No big deal, but toggle switches should minimize chance of mismatches.
Secondly, I switch a 12V cell between the 12V and 384V chains. During charging, the 12V cell is charged separately. After couple of miles of driving, the 12V cell is switch back into the 384V chain. This way, the expansion cells are cycled deeper than the main battery.
Thirdly, there are other prototype configurations. I guess I am driving my prototype lab around all the time.
...................SW1
----384Vchain----O-->O---+--chain continued
..........................|Z
..................O--12V--+
Ignore the periods - they are just placeholders
to make the ASCII spacing right.
Ok - that prevents shorting. If you need to totally
isolate the 12V from the chain, replace the connection
next to Z with another switch or a second set of contacts.
Using ASCII, draw what ever issue that leaves unsolved.
Trying to follow the concept you have in mind without
a schematic has apparently caused confusion.
Ed
F
Fred Bloggs
Guest
On Wednesday, May 31, 2023 at 11:32:03â¯AM UTC-4, Ed Lee wrote:
Then there\'s no power to short out.
On Wednesday, May 31, 2023 at 8:26:14â¯AM UTC-7, Fred Bloggs wrote:
On Wednesday, May 31, 2023 at 11:20:08â¯AM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 8:14:57â¯AM UTC-7, Fred Bloggs wrote:
On Tuesday, May 30, 2023 at 6:34:28â¯PM UTC-4, Ed Lee wrote:
On Tuesday, May 30, 2023 at 2:50:28â¯PM UTC-7, John Larkin wrote:
On Tue, 30 May 2023 14:18:35 -0700, Don Y
blocked...@foo.invalid> wrote:
On 5/30/2023 6:13 AM, Don Y wrote:
Find a *documented* switching mechanism. If you\'re switching
*DC*, expect the switch to be heavily derated. And, expect to
have to factor in some arcing during the transition. You
may be better off with a mercury-wetted *relay*, depending on
your application.
Note that switches are not \"ideal\" even when in steady state
but in *transition*, are complex creatures. A matED contact
will \"bounce\" as it is opened and a matING contact will bounce
as it\'s closing. Ideally, you want to know the time when the
contact is \"in flight\" AND the voltage rating at that point
(assuming any arcing has subsided -- that\'s YOUR calculation
not the switch manufacturer\'s as it depends on your application).
I can\'t find (online) the more comprehensive reference that I have
locally but here\'s ganssle\'s take on switch bounce. It\'s one of
my go-to documents for folks who THINK they understand the
dynamics of switches. E.g., folks seem to think switches
don\'t bounce when *opening* -- oops! :
Sometimes they don\'t.
Note the observation of a *relay* driven repeatedly by an MCU attached
to a storage scope (hard to drive a *switch* thusly) -- emphasis mine:
\"When the relay OPENED it always had a max bounce time of 2.3 to 2.9 msec,
at speeds from 2.5 to 30 Hz. More variation appeared on contact CLOSURE:
at 2.5 Hz bounces never exceeded 410 µsec, which climbed to 1080 µsec at
30 Hz. Why? I have no idea. But it\'s clear there is some correlation
between fast actuations and more bounce.\"
A relay will twang, namely ring like a bell, for a long time after a
transition. And bells have very complex vibration patterns. The twang
affects future actuations.
Reed relays make terrible analog multiplexers, because the high-Q
mechanical ringing makes voltages in the mag field and takes a long
time to die out.
I don\'t care about bouncing and/or ringing, as long as they don\'t short out the two throws. Some switches has center disconnect or middle throw, but they are not heavy duty rating. I might have a separate disconnect switch in series with the function switch, perhaps in lock box door type. The function switch is hidden inside the box. When the user open the lock box, the circuit should be disconnected.
Your voltages and current are easily handled by power MOSFETs.
But I don\'t trust the failure modes of semis and/or electronics.
You can use that failsafe technique where the one output actuates an NC relay that opens the other output. That way if the two outputs are on at the same time, they\'re both removed.
What if both outputs are off, with both NC relays and instant spark.
Then there\'s no power to short out.
E
Ed Lee
Guest
On Thursday, June 1, 2023 at 9:34:44â¯AM UTC-7, ehsjr wrote:
Yes, that\'s why I need a 4PDT or more switch. The 12V cell needs to be isolated from 384V and attached to another 12V source. The 12V gap of 384V also need to be shorted.
On 6/1/2023 9:50 AM, Ed Lee wrote:
On Thursday, June 1, 2023 at 1:32:18â¯AM UTC-7, Ricky wrote:
On Wednesday, May 31, 2023 at 9:56:41â¯PM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 5:43:46â¯PM UTC-7, Don Y wrote:
On 5/31/2023 4:41 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 3:25:18â¯PM UTC-7, Don Y wrote:
On 5/31/2023 8:02 AM, Ed Lee wrote:
Someone suggested mercury switches.
Ordered some to try out:
https://www.ebay.com/itm/195708179355?var=495574245862
No. Mercury *wetted* switches/relays/contactors. The switch contacts
are coated witha bit of mercury that allows the connection to be
maintained AS the switch would otherwise be bouncing; it \"snaps\"
open/closed more cleanly.
https://www.ebay.com/itm/155576690745
https://www.ebay.com/itm/134585850699
https://www.ebay.com/itm/155535895796
Selecting the proper \"switch\" will depend on your application and
the faults you are likely to encounter *or* that must be guarded
against.
You may have to augment the \"switch\" with other circuitry to
guard against things like welded contacts -- if such an event
can \"cause a problem/loss\".
Or, may choose to use different technologies to address
different aspects of your particular problem.
[E.g., UPSs have a mechanical shorting bar that can be removed
to isolate the battery; far more reliable than the relays inside!]
Yes, i am thinking about using mercury switches for lock box door. When the user flip up the door to access the function switch, it should disconnect the power source first.
(again, without knowing your application...) You can treat the \"door\"
as an armature and have it\'s opening *break* the contacts formed
by simply mating connectors (the traveling connector on the door
with the stationary one on the box)
Also got couple of ex-soviet military surplus heavy duty 16P2T switches. But probably hard to find any more. It can switch 8 independent power sources upto 3A.
https://www.ebay.com/itm/353292464636
Ex-soviet is good for something.
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
Firstly, my cells are between 100 to 2000 Whr, 12V and 16V. Eventually, they should all be 2000, but I don\'t have enough yet. I only have 3 16V 2000Wh cells so far. Eventually, there will be 24 16V 2000Wh. Until then, I mix them with groups of 12V 100 and 200 Whr cells. So, I need to switch the lower capacities in and out of the chain. Right now, i am doing it manually and trip the circuit breaker often. No big deal, but toggle switches should minimize chance of mismatches.
Secondly, I switch a 12V cell between the 12V and 384V chains. During charging, the 12V cell is charged separately. After couple of miles of driving, the 12V cell is switch back into the 384V chain. This way, the expansion cells are cycled deeper than the main battery.
Thirdly, there are other prototype configurations. I guess I am driving my prototype lab around all the time.
..................SW1
----384Vchain----O-->O---+--chain continued
.........................|Z
.................O--12V--+
Ignore the periods - they are just placeholders
to make the ASCII spacing right.
Ok - that prevents shorting. If you need to totally
isolate the 12V from the chain, replace the connection
next to Z with another switch or a second set of contacts.
Yes, that\'s why I need a 4PDT or more switch. The 12V cell needs to be isolated from 384V and attached to another 12V source. The 12V gap of 384V also need to be shorted.
E
Ed Lee
Guest
On Thursday, June 1, 2023 at 9:47:33â¯AM UTC-7, Fred Bloggs wrote:
The drive powers are out, but the target 384V is still on all the time
On Wednesday, May 31, 2023 at 11:32:03â¯AM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 8:26:14â¯AM UTC-7, Fred Bloggs wrote:
On Wednesday, May 31, 2023 at 11:20:08â¯AM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 8:14:57â¯AM UTC-7, Fred Bloggs wrote:
On Tuesday, May 30, 2023 at 6:34:28â¯PM UTC-4, Ed Lee wrote:
On Tuesday, May 30, 2023 at 2:50:28â¯PM UTC-7, John Larkin wrote:
On Tue, 30 May 2023 14:18:35 -0700, Don Y
blocked...@foo.invalid> wrote:
On 5/30/2023 6:13 AM, Don Y wrote:
Find a *documented* switching mechanism. If you\'re switching
*DC*, expect the switch to be heavily derated. And, expect to
have to factor in some arcing during the transition. You
may be better off with a mercury-wetted *relay*, depending on
your application.
Note that switches are not \"ideal\" even when in steady state
but in *transition*, are complex creatures. A matED contact
will \"bounce\" as it is opened and a matING contact will bounce
as it\'s closing. Ideally, you want to know the time when the
contact is \"in flight\" AND the voltage rating at that point
(assuming any arcing has subsided -- that\'s YOUR calculation
not the switch manufacturer\'s as it depends on your application).
I can\'t find (online) the more comprehensive reference that I have
locally but here\'s ganssle\'s take on switch bounce. It\'s one of
my go-to documents for folks who THINK they understand the
dynamics of switches. E.g., folks seem to think switches
don\'t bounce when *opening* -- oops! :
Sometimes they don\'t.
Note the observation of a *relay* driven repeatedly by an MCU attached
to a storage scope (hard to drive a *switch* thusly) -- emphasis mine:
\"When the relay OPENED it always had a max bounce time of 2..3 to 2.9 msec,
at speeds from 2.5 to 30 Hz. More variation appeared on contact CLOSURE:
at 2.5 Hz bounces never exceeded 410 µsec, which climbed to 1080 µsec at
30 Hz. Why? I have no idea. But it\'s clear there is some correlation
between fast actuations and more bounce.\"
A relay will twang, namely ring like a bell, for a long time after a
transition. And bells have very complex vibration patterns. The twang
affects future actuations.
Reed relays make terrible analog multiplexers, because the high-Q
mechanical ringing makes voltages in the mag field and takes a long
time to die out.
I don\'t care about bouncing and/or ringing, as long as they don\'t short out the two throws. Some switches has center disconnect or middle throw, but they are not heavy duty rating. I might have a separate disconnect switch in series with the function switch, perhaps in lock box door type.. The function switch is hidden inside the box. When the user open the lock box, the circuit should be disconnected.
Your voltages and current are easily handled by power MOSFETs.
But I don\'t trust the failure modes of semis and/or electronics.
You can use that failsafe technique where the one output actuates an NC relay that opens the other output. That way if the two outputs are on at the same time, they\'re both removed.
What if both outputs are off, with both NC relays and instant spark.
Then there\'s no power to short out.
The drive powers are out, but the target 384V is still on all the time
J
John Larkin
Guest
On Thu, 1 Jun 2023 08:58:50 -0700 (PDT), Ed Lee
<edward.ming.lee@gmail.com> wrote:
When I test relays I arrange for the scope to show three levels:
closed one side, floating mid-air, then closed on the other side.
https://www.dropbox.com/s/xamv86ilzp9g8cu/Z476_Fast_Off.jpg?raw=1
<edward.ming.lee@gmail.com> wrote:
On Thursday, June 1, 2023 at 8:51:56?AM UTC-7, John Larkin wrote:
On Thu, 1 Jun 2023 07:12:45 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
On Thursday, June 1, 2023 at 7:06:02?AM UTC-7, John Larkin wrote:
On Tue, 30 May 2023 00:42:15 -0700 (PDT), Ed Lee
edward....@gmail.com> wrote:
Anybody got access to this article:
https://pubmed.ncbi.nlm.nih.gov/18999467
regarding switch time of such switch:
https://www.ebay.com/itm/284624886322
Or simply a guess? 1/5 to 1/3 second?
Wow, 43 posts on the subject, mostly speculation.
Doesn\'t anybody have a switch and an oscilloscope?
https://quotefancy.com/media/wallpaper/3840x2160/859595-Wernher-von-Braun-Quote-One-good-test-is-worth-a-thousand-expert.jpg
I don\'t have a scope handy.
I can send you the switch and you can tell us with your scope.
We want to know switching time for 12V and 16V.
The little LCD scopes from ebay or amazon are pretty good, around $30.
You could get one of those for about what it would cost to ship me a
switch.
https://www.amazon.com/Digital-Oscilloscope-Portable-Sampling-Oscilloscopes/dp/B0BXD6JL8T/ref=sr_1_7_sspa?crid=1T98ZXGBI76PL&keywords=lcd+oscilloscope&qid=1685634469&sprefix=lcd+oscill%2Caps%2C161&sr=8-7-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTDVGT0xZVlo0TTlKJmVuY3J5cHRlZElkPUEwODM0Nzk3M0I5T1oyTVRJVTc4SyZlbmNyeXB0ZWRBZElkPUExMDM5OTQ2SkRPQTVPR0RRWllXJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
Then you would have a scope.
OK, i\'ll try it. I also sent a request to the manufacturer to do it. Let see if they will response.
When I test relays I arrange for the scope to show three levels:
closed one side, floating mid-air, then closed on the other side.
https://www.dropbox.com/s/xamv86ilzp9g8cu/Z476_Fast_Off.jpg?raw=1
D
Don Y
Guest
On 6/1/2023 9:50 AM, Ed Lee wrote:
WHAT is \"why I need a 4PDT or more switch\"?
Do you have at least one hand? That can hold a writing instrument?
And, a slip of paper on which you can make marks?
Is there some reason you can\'t SKETCH a schematic and post it
on one of the many *FREE* and PUBLIC servers?? Or, take a PHOTO
of it if you can\'t draw in a paint program...
Here is the part number of the item you need: 6%$g&0*&
it can be purchased from &^HGD(^q3-8we
(sorry, keyboard failure...)
<sheesh>
..................SW1
----384Vchain----O-->O---+--chain continued
.........................|Z
.................O--12V--+
Ignore the periods - they are just placeholders
to make the ASCII spacing right.
Ok - that prevents shorting. If you need to totally
isolate the 12V from the chain, replace the connection
next to Z with another switch or a second set of contacts.
Yes, that\'s why I need a 4PDT or more switch. The 12V cell needs to be isolated from 384V and attached to another 12V source. The 12V gap of 384V also need to be shorted.
WHAT is \"why I need a 4PDT or more switch\"?
Do you have at least one hand? That can hold a writing instrument?
And, a slip of paper on which you can make marks?
Is there some reason you can\'t SKETCH a schematic and post it
on one of the many *FREE* and PUBLIC servers?? Or, take a PHOTO
of it if you can\'t draw in a paint program...
Here is the part number of the item you need: 6%$g&0*&
it can be purchased from &^HGD(^q3-8we
(sorry, keyboard failure...)
<sheesh>
E
ehsjr
Guest
On 6/1/2023 12:50 PM, Ed Lee wrote:
Ok, so is this what you want?:
................SW1 4PDT
...............0.....0< wire shorts these 2 terminals
-384Vchain---0.....0----384Vchain continued
...............0.....0
...............|.....|
...............+-12V-+
...............|.....|
...............0.....0
..............0.....0 <these 2 terminals connect to charger
...............0.....0< no connection
(again, ignore the periods)
Ed
On Thursday, June 1, 2023 at 9:34:44â¯AM UTC-7, ehsjr wrote:
On 6/1/2023 9:50 AM, Ed Lee wrote:
On Thursday, June 1, 2023 at 1:32:18â¯AM UTC-7, Ricky wrote:
On Wednesday, May 31, 2023 at 9:56:41â¯PM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 5:43:46â¯PM UTC-7, Don Y wrote:
On 5/31/2023 4:41 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 3:25:18â¯PM UTC-7, Don Y wrote:
On 5/31/2023 8:02 AM, Ed Lee wrote:
Someone suggested mercury switches.
Ordered some to try out:
https://www.ebay.com/itm/195708179355?var=495574245862
No. Mercury *wetted* switches/relays/contactors. The switch contacts
are coated witha bit of mercury that allows the connection to be
maintained AS the switch would otherwise be bouncing; it \"snaps\"
open/closed more cleanly.
https://www.ebay.com/itm/155576690745
https://www.ebay.com/itm/134585850699
https://www.ebay.com/itm/155535895796
Selecting the proper \"switch\" will depend on your application and
the faults you are likely to encounter *or* that must be guarded
against.
You may have to augment the \"switch\" with other circuitry to
guard against things like welded contacts -- if such an event
can \"cause a problem/loss\".
Or, may choose to use different technologies to address
different aspects of your particular problem.
[E.g., UPSs have a mechanical shorting bar that can be removed
to isolate the battery; far more reliable than the relays inside!]
Yes, i am thinking about using mercury switches for lock box door. When the user flip up the door to access the function switch, it should disconnect the power source first.
(again, without knowing your application...) You can treat the \"door\"
as an armature and have it\'s opening *break* the contacts formed
by simply mating connectors (the traveling connector on the door
with the stationary one on the box)
Also got couple of ex-soviet military surplus heavy duty 16P2T switches. But probably hard to find any more. It can switch 8 independent power sources upto 3A.
https://www.ebay.com/itm/353292464636
Ex-soviet is good for something.
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
Firstly, my cells are between 100 to 2000 Whr, 12V and 16V. Eventually, they should all be 2000, but I don\'t have enough yet. I only have 3 16V 2000Wh cells so far. Eventually, there will be 24 16V 2000Wh. Until then, I mix them with groups of 12V 100 and 200 Whr cells. So, I need to switch the lower capacities in and out of the chain. Right now, i am doing it manually and trip the circuit breaker often. No big deal, but toggle switches should minimize chance of mismatches.
Secondly, I switch a 12V cell between the 12V and 384V chains. During charging, the 12V cell is charged separately. After couple of miles of driving, the 12V cell is switch back into the 384V chain. This way, the expansion cells are cycled deeper than the main battery.
Thirdly, there are other prototype configurations. I guess I am driving my prototype lab around all the time.
..................SW1
----384Vchain----O-->O---+--chain continued
.........................|Z
.................O--12V--+
Ignore the periods - they are just placeholders
to make the ASCII spacing right.
Ok - that prevents shorting. If you need to totally
isolate the 12V from the chain, replace the connection
next to Z with another switch or a second set of contacts.
Yes, that\'s why I need a 4PDT or more switch. The 12V cell needs to be isolated from 384V and attached to another 12V source. The 12V gap of 384V also need to be shorted.
Ok, so is this what you want?:
................SW1 4PDT
...............0.....0< wire shorts these 2 terminals
-384Vchain---0.....0----384Vchain continued
...............0.....0
...............|.....|
...............+-12V-+
...............|.....|
...............0.....0
..............0.....0 <these 2 terminals connect to charger
...............0.....0< no connection
(again, ignore the periods)
Ed
E
Ed Lee
Guest
On Thursday, June 1, 2023 at 12:50:51â¯PM UTC-7, ehsjr wrote:
Yes, that\'s the idea.
On 6/1/2023 12:50 PM, Ed Lee wrote:
On Thursday, June 1, 2023 at 9:34:44â¯AM UTC-7, ehsjr wrote:
On 6/1/2023 9:50 AM, Ed Lee wrote:
On Thursday, June 1, 2023 at 1:32:18â¯AM UTC-7, Ricky wrote:
On Wednesday, May 31, 2023 at 9:56:41â¯PM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 5:43:46â¯PM UTC-7, Don Y wrote:
On 5/31/2023 4:41 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 3:25:18â¯PM UTC-7, Don Y wrote:
On 5/31/2023 8:02 AM, Ed Lee wrote:
Someone suggested mercury switches.
Ordered some to try out:
https://www.ebay.com/itm/195708179355?var=495574245862
No. Mercury *wetted* switches/relays/contactors. The switch contacts
are coated witha bit of mercury that allows the connection to be
maintained AS the switch would otherwise be bouncing; it \"snaps\"
open/closed more cleanly.
https://www.ebay.com/itm/155576690745
https://www.ebay.com/itm/134585850699
https://www.ebay.com/itm/155535895796
Selecting the proper \"switch\" will depend on your application and
the faults you are likely to encounter *or* that must be guarded
against.
You may have to augment the \"switch\" with other circuitry to
guard against things like welded contacts -- if such an event
can \"cause a problem/loss\".
Or, may choose to use different technologies to address
different aspects of your particular problem.
[E.g., UPSs have a mechanical shorting bar that can be removed
to isolate the battery; far more reliable than the relays inside!]
Yes, i am thinking about using mercury switches for lock box door.. When the user flip up the door to access the function switch, it should disconnect the power source first.
(again, without knowing your application...) You can treat the \"door\"
as an armature and have it\'s opening *break* the contacts formed
by simply mating connectors (the traveling connector on the door
with the stationary one on the box)
Also got couple of ex-soviet military surplus heavy duty 16P2T switches. But probably hard to find any more. It can switch 8 independent power sources upto 3A.
https://www.ebay.com/itm/353292464636
Ex-soviet is good for something.
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
Firstly, my cells are between 100 to 2000 Whr, 12V and 16V. Eventually, they should all be 2000, but I don\'t have enough yet. I only have 3 16V 2000Wh cells so far. Eventually, there will be 24 16V 2000Wh. Until then, I mix them with groups of 12V 100 and 200 Whr cells. So, I need to switch the lower capacities in and out of the chain. Right now, i am doing it manually and trip the circuit breaker often. No big deal, but toggle switches should minimize chance of mismatches.
Secondly, I switch a 12V cell between the 12V and 384V chains. During charging, the 12V cell is charged separately. After couple of miles of driving, the 12V cell is switch back into the 384V chain. This way, the expansion cells are cycled deeper than the main battery.
Thirdly, there are other prototype configurations. I guess I am driving my prototype lab around all the time.
..................SW1
----384Vchain----O-->O---+--chain continued
.........................|Z
.................O--12V--+
Ignore the periods - they are just placeholders
to make the ASCII spacing right.
Ok - that prevents shorting. If you need to totally
isolate the 12V from the chain, replace the connection
next to Z with another switch or a second set of contacts.
Yes, that\'s why I need a 4PDT or more switch. The 12V cell needs to be isolated from 384V and attached to another 12V source. The 12V gap of 384V also need to be shorted.
Ok, so is this what you want?:
...............SW1 4PDT
..............0.....0< wire shorts these 2 terminals
-384Vchain---0.....0----384Vchain continued
..............0.....0
..............|.....|
..............+-12V-+
..............|.....|
..............0.....0
.............0.....0 <these 2 terminals connect to charger
..............0.....0< no connection
(again, ignore the periods)
Ed
Yes, that\'s the idea.
D
Don Y
Guest
On 6/1/2023 12:50 PM, ehsjr wrote:
You have more poles than you need. Check again.
On 6/1/2023 12:50 PM, Ed Lee wrote:
On Thursday, June 1, 2023 at 9:34:44â¯AM UTC-7, ehsjr wrote:
On 6/1/2023 9:50 AM, Ed Lee wrote:
On Thursday, June 1, 2023 at 1:32:18â¯AM UTC-7, Ricky wrote:
On Wednesday, May 31, 2023 at 9:56:41â¯PM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 5:43:46â¯PM UTC-7, Don Y wrote:
On 5/31/2023 4:41 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 3:25:18â¯PM UTC-7, Don Y wrote:
On 5/31/2023 8:02 AM, Ed Lee wrote:
Someone suggested mercury switches.
Ordered some to try out:
https://www.ebay.com/itm/195708179355?var=495574245862
No. Mercury *wetted* switches/relays/contactors. The switch contacts
are coated witha bit of mercury that allows the connection to be
maintained AS the switch would otherwise be bouncing; it \"snaps\"
open/closed more cleanly.
https://www.ebay.com/itm/155576690745
https://www.ebay.com/itm/134585850699
https://www.ebay.com/itm/155535895796
Selecting the proper \"switch\" will depend on your application and
the faults you are likely to encounter *or* that must be guarded
against.
You may have to augment the \"switch\" with other circuitry to
guard against things like welded contacts -- if such an event
can \"cause a problem/loss\".
Or, may choose to use different technologies to address
different aspects of your particular problem.
[E.g., UPSs have a mechanical shorting bar that can be removed
to isolate the battery; far more reliable than the relays inside!]
Yes, i am thinking about using mercury switches for lock box door. When
the user flip up the door to access the function switch, it should
disconnect the power source first.
(again, without knowing your application...) You can treat the \"door\"
as an armature and have it\'s opening *break* the contacts formed
by simply mating connectors (the traveling connector on the door
with the stationary one on the box)
Also got couple of ex-soviet military surplus heavy duty 16P2T
switches. But probably hard to find any more. It can switch 8
independent power sources upto 3A.
https://www.ebay.com/itm/353292464636
Ex-soviet is good for something.
What are you trying to *do*? (I have assumed, in mu comments, this was
something EVbattery related)
Switch 8 48V cells into 384V.
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
Firstly, my cells are between 100 to 2000 Whr, 12V and 16V. Eventually,
they should all be 2000, but I don\'t have enough yet. I only have 3 16V
2000Wh cells so far. Eventually, there will be 24 16V 2000Wh. Until then, I
mix them with groups of 12V 100 and 200 Whr cells. So, I need to switch the
lower capacities in and out of the chain. Right now, i am doing it manually
and trip the circuit breaker often. No big deal, but toggle switches should
minimize chance of mismatches.
Secondly, I switch a 12V cell between the 12V and 384V chains. During
charging, the 12V cell is charged separately. After couple of miles of
driving, the 12V cell is switch back into the 384V chain. This way, the
expansion cells are cycled deeper than the main battery.
Thirdly, there are other prototype configurations. I guess I am driving my
prototype lab around all the time.
..................SW1
----384Vchain----O-->O---+--chain continued
.........................|Z
.................O--12V--+
Ignore the periods - they are just placeholders
to make the ASCII spacing right.
Ok - that prevents shorting. If you need to totally
isolate the 12V from the chain, replace the connection
next to Z with another switch or a second set of contacts.
Yes, that\'s why I need a 4PDT or more switch. The 12V cell needs to be
isolated from 384V and attached to another 12V source. The 12V gap of 384V
also need to be shorted.
Ok, so is this what you want?:
...............SW1 4PDT
..............0.....0< wire shorts these 2 terminals
-384Vchain---0.....0----384Vchain continued
..............0.....0
..............|.....|
..............+-12V-+
..............|.....|
..............0.....0
.............0.....0 <these 2 terminals connect to charger
..............0.....0< no connection
(again, ignore the periods)
You have more poles than you need. Check again.
E
ehsjr
Guest
On 6/1/2023 10:16 PM, Don Y wrote:
I posted an ASCII \"schematic\" to check what he wanted.
Please modify it to show what you have in mind. That
will eliminate speculation. As I see it he needs
4 poles.
Ed
On 6/1/2023 12:50 PM, ehsjr wrote:
On 6/1/2023 12:50 PM, Ed Lee wrote:
On Thursday, June 1, 2023 at 9:34:44â¯AM UTC-7, ehsjr wrote:
On 6/1/2023 9:50 AM, Ed Lee wrote:
On Thursday, June 1, 2023 at 1:32:18â¯AM UTC-7, Ricky wrote:
On Wednesday, May 31, 2023 at 9:56:41â¯PM UTC-4, Ed Lee wrote:
On Wednesday, May 31, 2023 at 5:43:46â¯PM UTC-7, Don Y wrote:
On 5/31/2023 4:41 PM, Ed Lee wrote:
On Wednesday, May 31, 2023 at 3:25:18â¯PM UTC-7, Don Y wrote:
On 5/31/2023 8:02 AM, Ed Lee wrote:
Someone suggested mercury switches.
Ordered some to try out:
https://www.ebay.com/itm/195708179355?var=495574245862
No. Mercury *wetted* switches/relays/contactors. The switch
contacts
are coated witha bit of mercury that allows the connection to be
maintained AS the switch would otherwise be bouncing; it \"snaps\"
open/closed more cleanly.
https://www.ebay.com/itm/155576690745
https://www.ebay.com/itm/134585850699
https://www.ebay.com/itm/155535895796
Selecting the proper \"switch\" will depend on your application and
the faults you are likely to encounter *or* that must be guarded
against.
You may have to augment the \"switch\" with other circuitry to
guard against things like welded contacts -- if such an event
can \"cause a problem/loss\".
Or, may choose to use different technologies to address
different aspects of your particular problem.
[E.g., UPSs have a mechanical shorting bar that can be removed
to isolate the battery; far more reliable than the relays
inside!]
Yes, i am thinking about using mercury switches for lock box
door. When the user flip up the door to access the function
switch, it should disconnect the power source first.
(again, without knowing your application...) You can treat the
\"door\"
as an armature and have it\'s opening *break* the contacts formed
by simply mating connectors (the traveling connector on the door
with the stationary one on the box)
Also got couple of ex-soviet military surplus heavy duty 16P2T
switches. But probably hard to find any more. It can switch 8
independent power sources upto 3A.
https://www.ebay.com/itm/353292464636
Ex-soviet is good for something.
What are you trying to *do*? (I have assumed, in mu comments,
this was
something EVbattery related)
Switch 8 48V cells into 384V.
Why do you need switches? Just wire them in series.
So, what are you really trying to do?
Firstly, my cells are between 100 to 2000 Whr, 12V and 16V.
Eventually, they should all be 2000, but I don\'t have enough yet. I
only have 3 16V 2000Wh cells so far. Eventually, there will be 24
16V 2000Wh. Until then, I mix them with groups of 12V 100 and 200
Whr cells. So, I need to switch the lower capacities in and out of
the chain. Right now, i am doing it manually and trip the circuit
breaker often. No big deal, but toggle switches should minimize
chance of mismatches.
Secondly, I switch a 12V cell between the 12V and 384V chains.
During charging, the 12V cell is charged separately. After couple
of miles of driving, the 12V cell is switch back into the 384V
chain. This way, the expansion cells are cycled deeper than the
main battery.
Thirdly, there are other prototype configurations. I guess I am
driving my prototype lab around all the time.
..................SW1
----384Vchain----O-->O---+--chain continued
.........................|Z
.................O--12V--+
Ignore the periods - they are just placeholders
to make the ASCII spacing right.
Ok - that prevents shorting. If you need to totally
isolate the 12V from the chain, replace the connection
next to Z with another switch or a second set of contacts.
Yes, that\'s why I need a 4PDT or more switch. The 12V cell needs to
be isolated from 384V and attached to another 12V source. The 12V
gap of 384V also need to be shorted.
Ok, so is this what you want?:
...............SW1 4PDT
..............0.....0< wire shorts these 2 terminals
-384Vchain---0.....0----384Vchain continued
..............0.....0
..............|.....|
..............+-12V-+
..............|.....|
..............0.....0
.............0.....0 <these 2 terminals connect to charger
..............0.....0< no connection
(again, ignore the periods)
You have more poles than you need. Check again.
I posted an ASCII \"schematic\" to check what he wanted.
Please modify it to show what you have in mind. That
will eliminate speculation. As I see it he needs
4 poles.
Ed
B
Bertrand Sindri
Guest
ehsjr <ehsjr@verizon.net> wrote:
Provided the OP\'s 12V charger can float (a fact that the OP has not
indicated, given the low level of detail he has provided so far) then
this number of poles accomplish the switch in and out:
-384Vchain----+-----0...
...............|.........
...............|......0-!--384Vchain.continued
...............|........!
...............|.....0..!
...............|.....|..!
...............+-12V-+..!
...............|.....|..!
12V.charger>..0.....0..!
........................!
......................0-!-<12.V.charger
One downside is it will interrupt the 384V chain briefly while
toggling.
On 6/1/2023 10:16 PM, Don Y wrote:
On 6/1/2023 12:50 PM, ehsjr wrote:
Ok, so is this what you want?:
...............SW1 4PDT
..............0.....0< wire shorts these 2 terminals
-384Vchain---0.....0----384Vchain continued
..............0.....0
..............|.....|
..............+-12V-+
..............|.....|
..............0.....0
.............0.....0 <these 2 terminals connect to charger
..............0.....0< no connection
(again, ignore the periods)
You have more poles than you need. Check again.
I posted an ASCII \"schematic\" to check what he wanted.
Please modify it to show what you have in mind. That
will eliminate speculation. As I see it he needs
4 poles.
Provided the OP\'s 12V charger can float (a fact that the OP has not
indicated, given the low level of detail he has provided so far) then
this number of poles accomplish the switch in and out:
-384Vchain----+-----0...
...............|.........
...............|......0-!--384Vchain.continued
...............|........!
...............|.....0..!
...............|.....|..!
...............+-12V-+..!
...............|.....|..!
12V.charger>..0.....0..!
........................!
......................0-!-<12.V.charger
One downside is it will interrupt the 384V chain briefly while
toggling.