27 Nov
2014
27 Nov
'14
11:23 p.m.
I know this is not an electrical forum, but I thought perhaps someone
has seen what I am looking for.
For an application, I am looking for a relay that is connected to 12V
through a switch, with the switch voltage also going to the middle of a
SPDT relay contacts.
* If I energize the latch once, for the time the button in pressed,
the relay flips "on" and the middle relay contact sends power to the
NO contact
* If the energize the latch a second time, for the time the button is
pressed, the relay flips "off" and the middle relay contact sends
power to the NC contact.
The circuit works with an open relay of the kind they used to use in
garage doors (push button once, and door goes up, second press makes it
go down...) But, we need a sealed relay to beat the weather (it's for a
lineman's bucket truck we own).
Simulating this with some electronics and two relays won't work (well,
it would work, but it's for my father, and he really wants a
electrical/mechanical relay solution, like he has, but weathertight).
I thought for sure there was such a thing as a D-type FF in relay
format, but all of the magnetic and mechanical latching relays I see
online use two separate coils to operate, which means two switches, and
that won't work (no more signal paths available in this application).
I must not know what to call what I am looking for, and was hoping
someone had a better name for this type of thing or a suggestion of
where to look...
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
27 Nov
27 Nov
11:39 p.m.
Jim,
You'll probably need to search for a magnetic latching relay. I've found
a number of examples from Schneider, Rockwell, etc. However, the ones
I've found so far all have 24 VDC coils, not 12 VDC. If you look around
some of the electronics suppliers and/or eBay, you might come across the
exact model you need. If I see one, I'll forward the info along.
Regards,
Brian.
On 11/28/2014 02:23 AM, Jim Brain wrote:
I know this is not an electrical forum, but I thought
perhaps someone
has seen what I am looking for.
For an application, I am looking for a relay that is connected to 12V
through a switch, with the switch voltage also going to the middle of
a SPDT relay contacts.
* If I energize the latch once, for the time the button in pressed,
the relay flips "on" and the middle relay contact sends power to the
NO contact
* If the energize the latch a second time, for the time the button is
pressed, the relay flips "off" and the middle relay contact sends
power to the NC contact.
The circuit works with an open relay of the kind they used to use in
garage doors (push button once, and door goes up, second press makes
it go down...) But, we need a sealed relay to beat the weather (it's
for a lineman's bucket truck we own).
Simulating this with some electronics and two relays won't work (well,
it would work, but it's for my father, and he really wants a
electrical/mechanical relay solution, like he has, but weathertight).
I thought for sure there was such a thing as a D-type FF in relay
format, but all of the magnetic and mechanical latching relays I see
online use two separate coils to operate, which means two switches,
and that won't work (no more signal paths available in this application).
I must not know what to call what I am looking for, and was hoping
someone had a better name for this type of thing or a suggestion of
where to look...
Jim
11:51 p.m.
Here's one to take a look at, an NTE7742.
http://store.acradiosupplyinc.com/nterly7742relay-dpdt15a12vdc.aspx
They have the cut-sheet for it as well, maybe this will help.
Brian.
On 11/28/2014 02:23 AM, Jim Brain wrote:
I know this is not an electrical forum, but I thought
perhaps someone
has seen what I am looking for.
For an application, I am looking for a relay that is connected to 12V
through a switch, with the switch voltage also going to the middle of
a SPDT relay contacts.
* If I energize the latch once, for the time the button in pressed,
the relay flips "on" and the middle relay contact sends power to the
NO contact
* If the energize the latch a second time, for the time the button is
pressed, the relay flips "off" and the middle relay contact sends
power to the NC contact.
The circuit works with an open relay of the kind they used to use in
garage doors (push button once, and door goes up, second press makes
it go down...) But, we need a sealed relay to beat the weather (it's
for a lineman's bucket truck we own).
Simulating this with some electronics and two relays won't work (well,
it would work, but it's for my father, and he really wants a
electrical/mechanical relay solution, like he has, but weathertight).
I thought for sure there was such a thing as a D-type FF in relay
format, but all of the magnetic and mechanical latching relays I see
online use two separate coils to operate, which means two switches,
and that won't work (no more signal paths available in this application).
I must not know what to call what I am looking for, and was hoping
someone had a better name for this type of thing or a suggestion of
where to look...
Jim
28 Nov
28 Nov
12:23 p.m.
On 11/27/2014 11:23 PM, Jim Brain wrote:
I'm trying to wrap my mind around the problem. Does this describe it?
You want a push-on push-off circuit using only mechanical relays.
Am I reading you correctly?
--Chuck
1:21 p.m.
On Friday (11/28/2014 at 12:23PM -0800), Chuck Guzis wrote:
On 11/27/2014 11:23 PM, Jim Brain wrote:
I'm trying to wrap my mind around the problem. Does this describe it?
You want a push-on push-off circuit using only mechanical relays.
Am I reading you correctly?
How 'bout this,
http://s443.photobucket.com/user/ewyltj/media/push_switch.jpg.html
They show a 24V supply and relay coil but I see no reason a 12V supply
and coil couldn't be substituted.
The RC network is there to basically give you "opposite polarity" each
time you press the button. It's charged to roughly the supply voltage
when the relay is unenergized and when you press the button, dumps that
into the coil to pull in the relay.
Then, while the relay is energized, the RC network decays to close to
0V and so when you press the button again, it pulls the topside of the
relay coil to 0V, dropping out the relay.
The RC network is the memory part of your "D flip-flop" :-)
You will need a DPDT relay though so that the other set of contacts can
control your load.
Chris
--
Chris Elmquist
2:02 p.m.
On 11/28/2014 3:21 PM, Chris Elmquist wrote:
On Friday (11/28/2014 at 12:23PM -0800), Chuck Guzis
wrote:
I looked it it, but it doesn't seem to support the 3rd state (do
nothing).
JIm
--
Jim Brain
brain at jbrain.com
www.jbrain.com
On 11/27/2014 11:23 PM, Jim Brain wrote:
I'm trying to wrap my mind around the problem. Does this describe it?
You want a push-on push-off circuit using only mechanical relays.
Am I reading you correctly?
How 'bout this,
http://s443.photobucket.com/user/ewyltj/media/push_switch.jpg.html
They show a 24V supply and relay coil but I see no reason a 12V supply
and coil couldn't be substituted.
The RC network is there to basically give you "opposite polarity" each
time you press the button. It's charged to roughly the supply voltage
when the relay is unenergized and when you press the button, dumps that
into the coil to pull in the relay.
Then, while the relay is energized, the RC network decays to close to
0V and so when you press the button again, it pulls the topside of the
relay coil to 0V, dropping out the relay.
The RC network is the memory part of your "D flip-flop" :-)
You will need a DPDT relay though so that the other set of contacts can
control your load.
Chris
2:06 p.m.
On 11/28/2014 2:23 PM, Chuck Guzis wrote:
On 11/27/2014 11:23 PM, Jim Brain wrote:
I'm trying to wrap my mind around the problem. Does this describe it?
You want a push-on push-off circuit using only mechanical relays.
Am I reading you correctly?
--Chuck
hmm, not exactly....
To translate into electronics, it'd be like:
* Take a D FF
* hook it up in std divide by 2 mode (i.e., !Q = D)
* Take Q and attach it to a latch input with active enable line
* Take latch enable line and hook to CLK
So, on first CLK, the FF goes to 1, and the Latch allows 1 to flow out
of the unit
When CLK goes LOW, output goes to HiZ
When second CLK arrives, output goes low
When CLK goes low, HiZ
Output = 1 (hydraulic motor send lift up)
Output = HiZ (hydraulic motor off)
Output = 0 (hydraulic motor send lift down)
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
2:40 p.m.
Why not just do this the simple, usual way for an application like yours: a
pair of nice, sealed, heavy duty industrial pushbuttons marked UP and DOWN,
or even a single button with a nice heavy duty toggle switch similarly
marked?
Personally, I'd be a little leery pushing that button without knowing which
way the lift is going to move when I do...
m
----- Original Message -----
From: "Jim Brain" <brain at jbrain.com>
To: <General at classiccmp.org>; "Discussion at classiccmp.org:On-Topic and
Off-Topic Posts" <cctalk at classiccmp.org>
Sent: Friday, November 28, 2014 5:06 PM
Subject: Re: Relay question
On 11/28/2014 2:23 PM, Chuck Guzis wrote:
On 11/27/2014 11:23 PM, Jim Brain wrote:
I'm trying to wrap my mind around the problem. Does this describe it?
You want a push-on push-off circuit using only mechanical relays.
Am I reading you correctly?
--Chuck
hmm, not exactly....
To translate into electronics, it'd be like:
* Take a D FF
* hook it up in std divide by 2 mode (i.e., !Q = D)
* Take Q and attach it to a latch input with active enable line
* Take latch enable line and hook to CLK
So, on first CLK, the FF goes to 1, and the Latch allows 1 to flow out of
the unit
When CLK goes LOW, output goes to HiZ
When second CLK arrives, output goes low
When CLK goes low, HiZ
Output = 1 (hydraulic motor send lift up)
Output = HiZ (hydraulic motor off)
Output = 0 (hydraulic motor send lift down)
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
2:47 p.m.
On 11/28/2014 4:40 PM, Mike Stein wrote:
Why not just do this the simple, usual way for an
application like
yours: a pair of nice, sealed, heavy duty industrial pushbuttons
marked UP and DOWN, or even a single button with a nice heavy duty
toggle switch similarly marked?
For safety, the buttons on the lift (in the
bucket), are air switches,
with the actual electrical portion down below. I have not seen the
unit, but my father claims there is no more room for another air line in
the boom cable trace, so any more switches would have to be wireless, or
something else.
Personally, I'd be a little leery pushing that button without knowing
which way the lift is going to move when I do...
I think that's why he wants
the minimum complexity (no solid state,
etc.). I agree, there is some risk there, but he is currently happy
with the operation using an unsealed relay, I told him surely there
existing a sealed version of this thing.
Yes, I could happily re-engineer it for him, but just like ill conceived
concepts on a vintage machine, I'm being asked to just make the current
setup work, not create a new setup.
Jim
5:01 p.m.
Can you use a double pole button, use one pole to switch the relay and the
other to control the current through the contacts?
I.e. every time you push the button the direction reverses but the lift is
only energized as long as you hold the button in.
m
----- Original Message -----
From: "Jim Brain" <brain at jbrain.com>
To: <General at classiccmp.org>; "Discussion at classiccmp.org:On-Topic and
Off-Topic Posts" <cctalk at classiccmp.org>
Sent: Friday, November 28, 2014 5:47 PM
Subject: Re: Relay question
On 11/28/2014 4:40 PM, Mike Stein wrote:
Why not just do this the simple, usual way for an
application like yours:
a pair of nice, sealed, heavy duty industrial pushbuttons marked UP and
DOWN, or even a single button with a nice heavy duty toggle switch
similarly marked?
For safety, the buttons on the lift (in the bucket), are air
switches,
with the actual electrical portion down below. I have not seen the unit,
but my father claims there is no more room for another air line in the
boom cable trace, so any more switches would have to be wireless, or
something else.
Personally, I'd be a little leery pushing that button without knowing
which way the lift is going to move when I do...
I think that's why he wants
the minimum complexity (no solid state, etc.).
I agree, there is some risk there, but he is currently happy with the
operation using an unsealed relay, I told him surely there existing a
sealed version of this thing.
Yes, I could happily re-engineer it for him, but just like ill conceived
concepts on a vintage machine, I'm being asked to just make the current
setup work, not create a new setup.
Jim
7 p.m.
I still think I need a latching relay for the
"switching"
Well, yes, the sequencing (impulse) relay that Brian pointed you at:
http://store.acradiosupplyinc.com/nterly7742relay-dpdt15a12vdc.aspx
There are more 'industrial' versions but they tend to be more expensive;
e.g.:
http://www.digikey.ca/product-detail/en/S89R11APP1-120/PB515-ND/365948
http://magnecraft.thomasnet.com/item/relays/relays-latching-sequencing/pn-3…
m
----- Original Message -----
From: "Jim Brain" <brain at jbrain.com>
To: <General at classiccmp.org>; "Discussion at classiccmp.org:On-Topic and
Off-Topic Posts" <cctalk at classiccmp.org>
Sent: Friday, November 28, 2014 9:40 PM
Subject: Re: Relay question
> On 11/28/2014 7:01 PM, Mike Stein wrote:
>> Can you use a double pole button, use one pole to switch the relay and
>> the other to control the current through the contacts?
I still think I need a latching relay for the
"switching"
>
4:26 p.m.
On 11/28/2014 02:40 PM, Mike Stein wrote:
Why not just do this the simple, usual way for an
application like
yours: a pair of nice, sealed, heavy duty industrial pushbuttons marked
UP and DOWN, or even a single button with a nice heavy duty toggle
switch similarly marked?
Personally, I'd be a little leery pushing that button without knowing
which way the lift is going to move when I do...
So really, the sequence of the first 6 pushes of the button are:
Push 1: Lift goes up
Push 2: Lift stops
Push 3: List goes down
Push 4: Lift stops
Push 5: Lift goes up
Right?
5:09 p.m.
So really, the sequence of the first 6 pushes of the
button are:
Push 1: Lift goes up
Push 2: Lift stops
Push 3: List goes down
Push 4: Lift stops
Push 5: Lift goes up
Right?
Well, as I read it, it was more like
Push: lift goes up
Release: lift stops
Push: lift goes down
Release: lift stops
Push: lift goes up
...etc
/~\ The ASCII Mouse
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29 Nov
29 Nov
12:23 a.m.
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Jim Brain
Sent: 29 November 2014 02:40
To: General at classiccmp.org; Discussion at classiccmp.org:On-Topic and Off-
Topic Posts
Subject: Re: Relay question
On 11/28/2014 7:09 PM, Mouse wrote:
No need, you can get bi-stable relays that flip on a pulse and stay flipped.
E.g.
http://www.ebay.co.uk/itm/171362456669
although I can't find anyone with a US product. "Ebay.com" only shows me US
product...
Dave
G4UGM
Well, as I read it, it was more like
Push: lift goes up
Release: lift stops
Push: lift goes down
Release: lift stops
Push: lift goes up
...etc
Correct: It seems a neat bit of a brain exercise, actually.
Jim
28 Nov
28 Nov
6:37 p.m.
On 11/28/2014 6:26 PM, Chuck Guzis wrote:
On 11/28/2014 02:40 PM, Mike Stein wrote:
Hehe, no:
Push and Hold #1: lift goes up
Let go of switch: stops
Push and Hold #2: lift goes down
Let Go of switch: stops
repeat.
The CLK signal (as it were) length determines how long the motor engages
in the direction selected.
Jim
--
Jim Brain
brain at jbrain.com
www.jbrain.com
Why not just do this the simple, usual way for an
application like
yours: a pair of nice, sealed, heavy duty industrial pushbuttons marked
UP and DOWN, or even a single button with a nice heavy duty toggle
switch similarly marked?
Personally, I'd be a little leery pushing that button without knowing
which way the lift is going to move when I do...
So really, the sequence of the first 6 pushes of the button are:
Push 1: Lift goes up
Push 2: Lift stops
Push 3: List goes down
Push 4: Lift stops
Push 5: Lift goes up
Right?
3453
days inactive
3454
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17 comments
7 participants
participants (7)
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brain＠jbrain.com -
brian＠marstella.net -
cclist＠sydex.com -
chrise＠pobox.com -
dave.g4ugm＠gmail.com -
mhs.stein＠gmail.com -
mouse＠Rodents-Montreal.ORG