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Can someone help me put this together?

This is in theory right now, but here is what I am thinking:

I have a circuit that gets power by a triggerable event - the power
lasts for 60 seconds then cuts off.

When power is supplied, it activates a motor.

When the motor completes 1 revolution, it hits a switch (SW1).

SW1, when closed (hit my the motor) flips a relay (R1) which takes away
the power to the motor and remains in that position until the power is
cut to the circuit.

When the power to the circuit is cut, R1 flips back.

This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

Any ideas?

Thanks
 
B

Brian

Jan 1, 1970
0
This is in theory right now, but here is what I am thinking:

I have a circuit that gets power by a triggerable event - the power
lasts for 60 seconds then cuts off.

When power is supplied, it activates a motor.

When the motor completes 1 revolution, it hits a switch (SW1).

SW1, when closed (hit my the motor) flips a relay (R1) which takes away
the power to the motor and remains in that position until the power is
cut to the circuit.

When the power to the circuit is cut, R1 flips back.

This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

Any ideas?

Thanks

Is this what you want? http://www.fncwired.com/MotorExample/
Brian
 
This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

Any ideas?

Thanks

Are you expecting the motor to be reset somehow so that the whole
operation automatically happens over again when the trigger arrives a second
time?

It's fairly simple if the operation is a "once and only once" type.

Jim
 
P

petrus bitbyter

Jan 1, 1970
0
This is in theory right now, but here is what I am thinking:

I have a circuit that gets power by a triggerable event - the power
lasts for 60 seconds then cuts off.

When power is supplied, it activates a motor.

When the motor completes 1 revolution, it hits a switch (SW1).

SW1, when closed (hit my the motor) flips a relay (R1) which takes away
the power to the motor and remains in that position until the power is
cut to the circuit.

When the power to the circuit is cut, R1 flips back.

This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

Any ideas?

Thanks

Well, there are more ways to skin a cat, but it also depends. So let's asume
your SW1 makes contact for a while but brakes it shortly afterwards again.
So see below: When SW1 closes relay A is powered and a turns off the motor.
At the same time it shorts SW1 so when SW1 opens again the relay will stay
on until power goes down.

+-----------+-------
| |
| |
.-. _|_
( M ) |_/_|-
'-' |A
| |
| |
| +-------+
| | |
o\ o o /
\ /
a \ ./ SW1
o o
| |
----+-------+-------
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

It's elementary (Watson) that SW1 does not stay on because you may not be
abel to start the motor again. So other variants of SW1 will require another
solution.

petrus bitbyter
 
F

Fred Bloggs

Jan 1, 1970
0
This is in theory right now, but here is what I am thinking:
I have a circuit that gets power by a triggerable event - the power
lasts for 60 seconds then cuts off.

When power is supplied, it activates a motor.

When the motor completes 1 revolution, it hits a switch (SW1).

SW1, when closed (hit my the motor) flips a relay (R1) which takes
away the power to the motor and remains in that position until the
power is cut to the circuit.

When the power to the circuit is cut, R1 flips back.

This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

If the motor has enough momentum to drive past SW1 so that it closes
momentarily and then opens again, your idea works, just put SW1 in
series with self-latching R1 coil,like so. If SW1 doesn't reopen or
something else happens so that it is in closed position when power is
applied, then that's your problem.
View in a fixed-width font such as Courier.
 
J

John Fields

Jan 1, 1970
0
This is in theory right now, but here is what I am thinking:

I have a circuit that gets power by a triggerable event - the power
lasts for 60 seconds then cuts off.

When power is supplied, it activates a motor.

When the motor completes 1 revolution, it hits a switch (SW1).

SW1, when closed (hit my the motor) flips a relay (R1) which takes away
the power to the motor and remains in that position until the power is
cut to the circuit.

When the power to the circuit is cut, R1 flips back.

This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

Any ideas?



SWITCHED POWER IN>---+------O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

Switched power comes in, goes through the normally closed contacts
of the relay and into the motor, which starts turning. After one
revolution, the motor closes S1, which allows current to flow
through the relay's coil, opening the contacts, stopping the motor.
As long as the motor doesn't override the switch, current will
continue to flow through the relay's coil, keeping the motor off.

If the switched power is cut, there will be no more current into the
relay coil, so the contacts will close allowing current to flow into
the motor the next time the power is switched on. Unfortunately, S1
will still be made because the motor stopped when its contacts
closed, so when power comes back on, current will flow through the
relay coil, opening the relay's contacts and keeping the motor from
turning.

So it seems like what you need is a way to make the relay work
quickly when the switch closes, but which will will keep it from
turning on for a while when power is switched on, in order to let it
ride over the switch at the start of the cycle.

Since this seems to be essentially the same application you asked
for on seb under "Probably a simple question, but...", I've posted a
solution for you on abse under "Probably a simple question, but...
(from seb)".

In the future, if you'd crosspost it would make it a lot easier for
everyone concerned to keep track of what's going on. :)
 
F

Fred Bloggs

Jan 1, 1970
0
John said:
This is in theory right now, but here is what I am thinking:

I have a circuit that gets power by a triggerable event - the power
lasts for 60 seconds then cuts off.

When power is supplied, it activates a motor.

When the motor completes 1 revolution, it hits a switch (SW1).

SW1, when closed (hit my the motor) flips a relay (R1) which takes away
the power to the motor and remains in that position until the power is
cut to the circuit.

When the power to the circuit is cut, R1 flips back.

This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

Any ideas?




SWITCHED POWER IN>---+------O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

Switched power comes in, goes through the normally closed contacts
of the relay and into the motor, which starts turning. After one
revolution, the motor closes S1, which allows current to flow
through the relay's coil, opening the contacts, stopping the motor.
As long as the motor doesn't override the switch, current will
continue to flow through the relay's coil, keeping the motor off.

If the switched power is cut, there will be no more current into the
relay coil, so the contacts will close allowing current to flow into
the motor the next time the power is switched on. Unfortunately, S1
will still be made because the motor stopped when its contacts
closed, so when power comes back on, current will flow through the
relay coil, opening the relay's contacts and keeping the motor from
turning.

So it seems like what you need is a way to make the relay work
quickly when the switch closes, but which will will keep it from
turning on for a while when power is switched on, in order to let it
ride over the switch at the start of the cycle.

Since this seems to be essentially the same application you asked
for on seb under "Probably a simple question, but...", I've posted a
solution for you on abse under "Probably a simple question, but...
(from seb)".

In the future, if you'd crosspost it would make it a lot easier for
everyone concerned to keep track of what's going on. :)

Well- he said the motor "hits" the switch, and there are all sorts of
mechanisms that will do that, so it's safe to assume the switch is
pulsed ON momentarily regardless of further motor travel. Then the only
requirement is that the switch close time exceeds R1 worst case
activation time, and R1 is self-latching with power applied.
 
J

John Fields

Jan 1, 1970
0
John said:
This is in theory right now, but here is what I am thinking:

I have a circuit that gets power by a triggerable event - the power
lasts for 60 seconds then cuts off.

When power is supplied, it activates a motor.

When the motor completes 1 revolution, it hits a switch (SW1).

SW1, when closed (hit my the motor) flips a relay (R1) which takes away
the power to the motor and remains in that position until the power is
cut to the circuit.

When the power to the circuit is cut, R1 flips back.

This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

Any ideas?




SWITCHED POWER IN>---+------O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

Switched power comes in, goes through the normally closed contacts
of the relay and into the motor, which starts turning. After one
revolution, the motor closes S1, which allows current to flow
through the relay's coil, opening the contacts, stopping the motor.
As long as the motor doesn't override the switch, current will
continue to flow through the relay's coil, keeping the motor off.

If the switched power is cut, there will be no more current into the
relay coil, so the contacts will close allowing current to flow into
the motor the next time the power is switched on. Unfortunately, S1
will still be made because the motor stopped when its contacts
closed, so when power comes back on, current will flow through the
relay coil, opening the relay's contacts and keeping the motor from
turning.

So it seems like what you need is a way to make the relay work
quickly when the switch closes, but which will will keep it from
turning on for a while when power is switched on, in order to let it
ride over the switch at the start of the cycle.

Since this seems to be essentially the same application you asked
for on seb under "Probably a simple question, but...", I've posted a
solution for you on abse under "Probably a simple question, but...
(from seb)".

In the future, if you'd crosspost it would make it a lot easier for
everyone concerned to keep track of what's going on. :)

Well- he said the motor "hits" the switch, and there are all sorts of
mechanisms that will do that, so it's safe to assume the switch is
pulsed ON momentarily regardless of further motor travel. Then the only
requirement is that the switch close time exceeds R1 worst case
activation time, and R1 is self-latching with power applied.
 
P

petrus bitbyter

Jan 1, 1970
0
John Fields said:
John said:
On 23 Oct 2005 08:49:55 -0700, [email protected] wrote:


This is in theory right now, but here is what I am thinking:

I have a circuit that gets power by a triggerable event - the power
lasts for 60 seconds then cuts off.

When power is supplied, it activates a motor.

When the motor completes 1 revolution, it hits a switch (SW1).

SW1, when closed (hit my the motor) flips a relay (R1) which takes away
the power to the motor and remains in that position until the power is
cut to the circuit.

When the power to the circuit is cut, R1 flips back.

This way, I can shut the motor off after completing one revolution
regardless of how long the power to the circuit is applied. Once the
power to the circuit is cut, R1 flips back.

This seems to me like it should work, but I cannot for the life of me
figure a schematic to wire it up.

Any ideas?




SWITCHED POWER IN>---+------O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

Switched power comes in, goes through the normally closed contacts
of the relay and into the motor, which starts turning. After one
revolution, the motor closes S1, which allows current to flow
through the relay's coil, opening the contacts, stopping the motor.
As long as the motor doesn't override the switch, current will
continue to flow through the relay's coil, keeping the motor off.

If the switched power is cut, there will be no more current into the
relay coil, so the contacts will close allowing current to flow into
the motor the next time the power is switched on. Unfortunately, S1
will still be made because the motor stopped when its contacts
closed, so when power comes back on, current will flow through the
relay coil, opening the relay's contacts and keeping the motor from
turning.

So it seems like what you need is a way to make the relay work
quickly when the switch closes, but which will will keep it from
turning on for a while when power is switched on, in order to let it
ride over the switch at the start of the cycle.

Since this seems to be essentially the same application you asked
for on seb under "Probably a simple question, but...", I've posted a
solution for you on abse under "Probably a simple question, but...
(from seb)".

In the future, if you'd crosspost it would make it a lot easier for
everyone concerned to keep track of what's going on. :)

Well- he said the motor "hits" the switch, and there are all sorts of
mechanisms that will do that, so it's safe to assume the switch is
pulsed ON momentarily regardless of further motor travel. Then the only
requirement is that the switch close time exceeds R1 worst case
activation time, and R1 is self-latching with power applied.

John,

As too often it all depends. This time the properties of SW1 stipulate the
possibilities you have for a solution. In the simple ones, timing will be
critical. For instance, when you assume SW1 to be a momentary switch, you
must be sure the motor cannot stop while SW1 is closed. So the relay you use
should be fast enough to be activated by SWI but SW1 (or the motor) should
be fast enough to have SW1 released before the motor actually stops. Another
SW1 requires another approach and you may need an extra relay or other
electronics to make it work the way you want. Worsed case you cannot be sure
whether or not SW1 is closed which requires some memory in a reliable
circuit. I'm sure you are able to make a working circuit but I don't like to
draw more schematics without more information from the side of the OP.

petrus bitbyter
 
J

John Fields

Jan 1, 1970
0
John,

As too often it all depends. This time the properties of SW1 stipulate the
possibilities you have for a solution. In the simple ones, timing will be
critical. For instance, when you assume SW1 to be a momentary switch, you
must be sure the motor cannot stop while SW1 is closed. So the relay you use
should be fast enough to be activated by SWI but SW1 (or the motor) should
be fast enough to have SW1 released before the motor actually stops. Another
SW1 requires another approach and you may need an extra relay or other
electronics to make it work the way you want. Worsed case you cannot be sure
whether or not SW1 is closed which requires some memory in a reliable
circuit. I'm sure you are able to make a working circuit but I don't like to
draw more schematics without more information from the side of the OP.
 
F

Fred Bloggs

Jan 1, 1970
0
That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.
 
J

John Fields

Jan 1, 1970
0
That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| |
+-----+ |
|TIMER| |
+-----+ |
| O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.
 
J

John Fields

Jan 1, 1970
0
That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| |
+-----+ |
|TIMER| |
+-----+ |
| O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.

---
Aarrghhh...

There's still a problem in that if the timer keeps the coil from
being energized for a while when the switched mains in goes hot
_and_ S1 is made, the same thing'll happen when S1 is made by the
motor riding over it, since it was open before that and the timer
was waiting for a current path to start its timeout. That is, when
the timer sees mains voltage across itself (and passes just enough
current to make its timer work without pulling in K1) K1 won't be
able to pull in until S1 is released, but by then it'll be too late,
and the motor will never stop.

Intrigueing problem to try to solve from just the AC side...

More tomorrow...

Si Dios quiere.
 
F

Fred Bloggs

Jan 1, 1970
0
John said:
That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| |
+-----+ |
|TIMER| |
+-----+ |
| O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.


---
Aarrghhh...

There's still a problem in that if the timer keeps the coil from
being energized for a while when the switched mains in goes hot
_and_ S1 is made, the same thing'll happen when S1 is made by the
motor riding over it, since it was open before that and the timer
was waiting for a current path to start its timeout. That is, when
the timer sees mains voltage across itself (and passes just enough
current to make its timer work without pulling in K1) K1 won't be
able to pull in until S1 is released, but by then it'll be too late,
and the motor will never stop.

Intrigueing problem to try to solve from just the AC side...

More tomorrow...

Si Dios quiere.

Right- I was wondering about that. The only way this can work is to
detect a transition from open to close and and vice versa in S1, any
control relying on S1 static position or polarity of transition will
fail. Forgetting about any particular hardware for the moment, if you
can configure a detection circuit that is somehow "armed" by the
sequence of S1 moving from initial to opposite state and then triggers
the self-latching NC power relay when S1 returns to the initial state,
this should do it. If power first comes up with S1 open, then the
trigger arms when S1 closes and triggers motor off when S1 re-opens. If
power comes up with S1 closed, the trigger arms when S1 opens, and
triggers when S1 re-closes. The end result is that the motor always
stops at the SW position after making at most one revolution. If you
want the motor to fall into always stopping when S1 closes, then you
could a timer that applies to the arming logic so that if S1 was open
initially, but the motor has run a minimum predetermined time, the
trigger logic will fire on first closure.
 
J

John Fields

Jan 1, 1970
0
John said:
That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| |
+-----+ |
|TIMER| |
+-----+ |
| O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.


---
Aarrghhh...

There's still a problem in that if the timer keeps the coil from
being energized for a while when the switched mains in goes hot
_and_ S1 is made, the same thing'll happen when S1 is made by the
motor riding over it, since it was open before that and the timer
was waiting for a current path to start its timeout. That is, when
the timer sees mains voltage across itself (and passes just enough
current to make its timer work without pulling in K1) K1 won't be
able to pull in until S1 is released, but by then it'll be too late,
and the motor will never stop.

Intrigueing problem to try to solve from just the AC side...

More tomorrow...

Si Dios quiere.

Right- I was wondering about that. The only way this can work is to
detect a transition from open to close and and vice versa in S1, any
control relying on S1 static position or polarity of transition will
fail. Forgetting about any particular hardware for the moment, if you
can configure a detection circuit that is somehow "armed" by the
sequence of S1 moving from initial to opposite state and then triggers
the self-latching NC power relay when S1 returns to the initial state,
this should do it. If power first comes up with S1 open, then the
trigger arms when S1 closes and triggers motor off when S1 re-opens. If
power comes up with S1 closed, the trigger arms when S1 opens, and
triggers when S1 re-closes. The end result is that the motor always
stops at the SW position after making at most one revolution. If you
want the motor to fall into always stopping when S1 closes, then you
could a timer that applies to the arming logic so that if S1 was open
initially, but the motor has run a minimum predetermined time, the
trigger logic will fire on first closure.


---
I think I got it. Check it out:


SWITCHED MAINS IN>--+----------------+
| |
+-----+ |
|TIMER| +----+
+-----+ | |
| | |
+--|-----------|-+ |
| | K1 O | |
|[COIL]- - - - | | |
| | O--> | | |
| | | NO | |
+--|------|------+ |
| | |
| | |
| +--|---------|----+
| | | K2 O |
| |[COIL]- - - | |
| | | |<-O----+
| | | NC | |
| +--|--------------+ |
| | |
| O | |
| S1 |<- - - - - -[MOTOR]
| O | |
| | |
RETURN>-------------+------+-----------------+

Assume the motor is parked on S1, which is closed, and that
"SWITCHED MAINS IN" has just gone hot.

Because of the timer's delay, K1's coil won't be energized, its
contacts won't be made, K2's coil won't be enerized and its
contacts will remain closed, allowing current to flow into the
motor, causing it to turn. After the motor clears S1 and S1 opens,
the timer will time out, allowing K1's coil to be energized and its
contacts to make. That will supply power to K2's coil,
conditionally enabling it, and as soon as the motor hits S1, K2's
coil will be energized, its contacts will open, and the motor will
stop turning.

Subsequent to that, if the mains are switched off and then on again
a new cycle will start.

If, in the middle of a cycle, the mains are switched off and then on
again, the motor will stop and then start instantly as soon as the
mains are switched on again, and the motor will rotate until it
makes S1.

There is the remote possibility (depending on the length of the
timer's 'on' delay that if the mains were switched off while the
motor was running and the motor stopped just before it made S1, that
on the subsequent power-up it would ride over S1 without stopping.
However, it would stop on the next time around.

I don't see any holes in it, but what do you think?
 
P

petrus bitbyter

Jan 1, 1970
0
Fred Bloggs said:
John said:
That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| | +-----+ |
|TIMER| | +-----+ | | O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.


---
Aarrghhh...

There's still a problem in that if the timer keeps the coil from
being energized for a while when the switched mains in goes hot
_and_ S1 is made, the same thing'll happen when S1 is made by the
motor riding over it, since it was open before that and the timer
was waiting for a current path to start its timeout. That is, when
the timer sees mains voltage across itself (and passes just enough
current to make its timer work without pulling in K1) K1 won't be
able to pull in until S1 is released, but by then it'll be too late,
and the motor will never stop.

Intrigueing problem to try to solve from just the AC side...

More tomorrow...

Si Dios quiere.

Right- I was wondering about that. The only way this can work is to detect
a transition from open to close and and vice versa in S1, any control
relying on S1 static position or polarity of transition will fail.
Forgetting about any particular hardware for the moment, if you can
configure a detection circuit that is somehow "armed" by the sequence of
S1 moving from initial to opposite state and then triggers the
self-latching NC power relay when S1 returns to the initial state, this
should do it. If power first comes up with S1 open, then the trigger arms
when S1 closes and triggers motor off when S1 re-opens. If power comes up
with S1 closed, the trigger arms when S1 opens, and triggers when S1
re-closes. The end result is that the motor always stops at the SW
position after making at most one revolution. If you want the motor to
fall into always stopping when S1 closes, then you could a timer that
applies to the arming logic so that if S1 was open initially, but the
motor has run a minimum predetermined time, the trigger logic will fire on
first closure.


Can't help but giving it a second look. I'm sure all simple solutions may
run into timing or exception problems like I said before. The solution below
is not very simple but should work always.


+--------+---------+---------+
| | | |
| | | |
.-. _|_ _|_ _|_
( M ) |_/_|- |_/_|- |_/_|-
'-' |A |B |S
| | | |
| | | |
+----------------------+ |
| | | | |
| | | | |
| | | | |
| +--------o / o / o /
| | / / /
| | /a1 /a2 / SW1
| | o o o
| | | | |
| | +----+----+ |
| | | |
| | | |
o /o /o |
/ / |
/ b / s |
o o |
| | |
+-------------+------------------+--
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

S can be omitted when SW1 has a normally closed contact that can stand the
motor current, so SW1 can replace the s-contact. If you have to use the
S-relay, it should be fast with respect to the A- and B-relays.

petrus bitbyter
 
J

John Fields

Jan 1, 1970
0
Fred Bloggs said:
John said:
On Wed, 26 Oct 2005 12:04:41 -0500, John Fields


That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| | +-----+ |
|TIMER| | +-----+ | | O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.


---
Aarrghhh...

There's still a problem in that if the timer keeps the coil from
being energized for a while when the switched mains in goes hot
_and_ S1 is made, the same thing'll happen when S1 is made by the
motor riding over it, since it was open before that and the timer
was waiting for a current path to start its timeout. That is, when
the timer sees mains voltage across itself (and passes just enough
current to make its timer work without pulling in K1) K1 won't be
able to pull in until S1 is released, but by then it'll be too late,
and the motor will never stop.

Intrigueing problem to try to solve from just the AC side...

More tomorrow...

Si Dios quiere.

Right- I was wondering about that. The only way this can work is to detect
a transition from open to close and and vice versa in S1, any control
relying on S1 static position or polarity of transition will fail.
Forgetting about any particular hardware for the moment, if you can
configure a detection circuit that is somehow "armed" by the sequence of
S1 moving from initial to opposite state and then triggers the
self-latching NC power relay when S1 returns to the initial state, this
should do it. If power first comes up with S1 open, then the trigger arms
when S1 closes and triggers motor off when S1 re-opens. If power comes up
with S1 closed, the trigger arms when S1 opens, and triggers when S1
re-closes. The end result is that the motor always stops at the SW
position after making at most one revolution. If you want the motor to
fall into always stopping when S1 closes, then you could a timer that
applies to the arming logic so that if S1 was open initially, but the
motor has run a minimum predetermined time, the trigger logic will fire on
first closure.


Can't help but giving it a second look. I'm sure all simple solutions may
run into timing or exception problems like I said before. The solution below
is not very simple but should work always.


+--------+---------+---------+
| | | |
| | | |
.-. _|_ _|_ _|_
( M ) |_/_|- |_/_|- |_/_|-
'-' |A |B |S
| | | |
| | | |
+----------------------+ |
| | | | |
| | | | |
| | | | |
| +--------o / o / o /
| | / / /
| | /a1 /a2 / SW1
| | o o o
| | | | |
| | +----+----+ |
| | | |
| | | |
o /o /o |
/ / |
/ b / s |
o o |
| | |
+-------------+------------------+--
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

S can be omitted when SW1 has a normally closed contact that can stand the
motor current, so SW1 can replace the s-contact. If you have to use the
S-relay, it should be fast with respect to the A- and B-relays.
 
J

John Fields

Jan 1, 1970
0
Fred Bloggs said:
John Fields wrote:
On Wed, 26 Oct 2005 12:04:41 -0500, John Fields


That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| | +-----+ |
|TIMER| | +-----+ | | O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.


---
Aarrghhh...

There's still a problem in that if the timer keeps the coil from
being energized for a while when the switched mains in goes hot
_and_ S1 is made, the same thing'll happen when S1 is made by the
motor riding over it, since it was open before that and the timer
was waiting for a current path to start its timeout. That is, when
the timer sees mains voltage across itself (and passes just enough
current to make its timer work without pulling in K1) K1 won't be
able to pull in until S1 is released, but by then it'll be too late,
and the motor will never stop.

Intrigueing problem to try to solve from just the AC side...

More tomorrow...

Si Dios quiere.


Right- I was wondering about that. The only way this can work is to detect
a transition from open to close and and vice versa in S1, any control
relying on S1 static position or polarity of transition will fail.
Forgetting about any particular hardware for the moment, if you can
configure a detection circuit that is somehow "armed" by the sequence of
S1 moving from initial to opposite state and then triggers the
self-latching NC power relay when S1 returns to the initial state, this
should do it. If power first comes up with S1 open, then the trigger arms
when S1 closes and triggers motor off when S1 re-opens. If power comes up
with S1 closed, the trigger arms when S1 opens, and triggers when S1
re-closes. The end result is that the motor always stops at the SW
position after making at most one revolution. If you want the motor to
fall into always stopping when S1 closes, then you could a timer that
applies to the arming logic so that if S1 was open initially, but the
motor has run a minimum predetermined time, the trigger logic will fire on
first closure.


Can't help but giving it a second look. I'm sure all simple solutions may
run into timing or exception problems like I said before. The solution below
is not very simple but should work always.


+--------+---------+---------+
| | | |
| | | |
.-. _|_ _|_ _|_
( M ) |_/_|- |_/_|- |_/_|-
'-' |A |B |S
| | | |
| | | |
+----------------------+ |
| | | | |
| | | | |
| | | | |
| +--------o / o / o /
| | / / /
| | /a1 /a2 / SW1
| | o o o
| | | | |
| | +----+----+ |
| | | |
| | | |
o /o /o |
/ / |
/ b / s |
o o |
| | |
+-------------+------------------+--
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

S can be omitted when SW1 has a normally closed contact that can stand the
motor current, so SW1 can replace the s-contact. If you have to use the
S-relay, it should be fast with respect to the A- and B-relays.

Well, maybe not for less hardware bux since the time delay relay is
kind of expensive, but since it'll surely eliminate the need for
grading the other relays in terms of speed, according to you,
there'll be some cost advantage gained there...

Which relays did you have in mind?
 
F

Fred Bloggs

Jan 1, 1970
0
John said:
John said:
On Wed, 26 Oct 2005 12:04:41 -0500, John Fields



That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| |
+-----+ |
|TIMER| |
+-----+ |
| O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.


---
Aarrghhh...

There's still a problem in that if the timer keeps the coil from
being energized for a while when the switched mains in goes hot
_and_ S1 is made, the same thing'll happen when S1 is made by the
motor riding over it, since it was open before that and the timer
was waiting for a current path to start its timeout. That is, when
the timer sees mains voltage across itself (and passes just enough
current to make its timer work without pulling in K1) K1 won't be
able to pull in until S1 is released, but by then it'll be too late,
and the motor will never stop.

Intrigueing problem to try to solve from just the AC side...

More tomorrow...

Si Dios quiere.

Right- I was wondering about that. The only way this can work is to
detect a transition from open to close and and vice versa in S1, any
control relying on S1 static position or polarity of transition will
fail. Forgetting about any particular hardware for the moment, if you
can configure a detection circuit that is somehow "armed" by the
sequence of S1 moving from initial to opposite state and then triggers
the self-latching NC power relay when S1 returns to the initial state,
this should do it. If power first comes up with S1 open, then the
trigger arms when S1 closes and triggers motor off when S1 re-opens. If
power comes up with S1 closed, the trigger arms when S1 opens, and
triggers when S1 re-closes. The end result is that the motor always
stops at the SW position after making at most one revolution. If you
want the motor to fall into always stopping when S1 closes, then you
could a timer that applies to the arming logic so that if S1 was open
initially, but the motor has run a minimum predetermined time, the
trigger logic will fire on first closure.



---
I think I got it. Check it out:


SWITCHED MAINS IN>--+----------------+
| |
+-----+ |
|TIMER| +----+
+-----+ | |
| | |
+--|-----------|-+ |
| | K1 O | |
|[COIL]- - - - | | |
| | O--> | | |
| | | NO | |
+--|------|------+ |
| | |
| | |
| +--|---------|----+
| | | K2 O |
| |[COIL]- - - | |
| | | |<-O----+
| | | NC | |
| +--|--------------+ |
| | |
| O | |
| S1 |<- - - - - -[MOTOR]
| O | |
| | |
RETURN>-------------+------+-----------------+

Assume the motor is parked on S1, which is closed, and that
"SWITCHED MAINS IN" has just gone hot.

Because of the timer's delay, K1's coil won't be energized, its
contacts won't be made, K2's coil won't be enerized and its
contacts will remain closed, allowing current to flow into the
motor, causing it to turn. After the motor clears S1 and S1 opens,
the timer will time out, allowing K1's coil to be energized and its
contacts to make. That will supply power to K2's coil,
conditionally enabling it, and as soon as the motor hits S1, K2's
coil will be energized, its contacts will open, and the motor will
stop turning.

Subsequent to that, if the mains are switched off and then on again
a new cycle will start.

If, in the middle of a cycle, the mains are switched off and then on
again, the motor will stop and then start instantly as soon as the
mains are switched on again, and the motor will rotate until it
makes S1.

There is the remote possibility (depending on the length of the
timer's 'on' delay that if the mains were switched off while the
motor was running and the motor stopped just before it made S1, that
on the subsequent power-up it would ride over S1 without stopping.
However, it would stop on the next time around.

I don't see any holes in it, but what do you think?

I think that solution is perfect:)
 
P

petrus bitbyter

Jan 1, 1970
0
John Fields said:
"Fred Bloggs" <[email protected]> schreef in bericht


John Fields wrote:
On Wed, 26 Oct 2005 12:04:41 -0500, John Fields


That works- but is there an AC solution? Motor is heavily geared and
turns slowly- stops on a dime.

---
Yes.

Use an adjustable delay-on-make timer like an ICM Controls ICM102 or
a WW Grainger 4E233,(they're the same part) like this:


SWITCHED MAINS IN>---+------+
| | +-----+ |
|TIMER| | +-----+ | | O
| |K1
[COIL]- -|<---O
| |
O | |
S1 |<- - -[MOTOR]
O | |
| |
RETURN>--------------+-----------+

That way, If S1 is closed because the motor stopped when it (S1)
closed, the timer will block the flow of current into the coil of
K1, keeping K1 de-energized until the motor turns enough to release
S1.


---
Aarrghhh...

There's still a problem in that if the timer keeps the coil from
being energized for a while when the switched mains in goes hot
_and_ S1 is made, the same thing'll happen when S1 is made by the
motor riding over it, since it was open before that and the timer
was waiting for a current path to start its timeout. That is, when
the timer sees mains voltage across itself (and passes just enough
current to make its timer work without pulling in K1) K1 won't be
able to pull in until S1 is released, but by then it'll be too late,
and the motor will never stop.

Intrigueing problem to try to solve from just the AC side...

More tomorrow...

Si Dios quiere.


Right- I was wondering about that. The only way this can work is to
detect
a transition from open to close and and vice versa in S1, any control
relying on S1 static position or polarity of transition will fail.
Forgetting about any particular hardware for the moment, if you can
configure a detection circuit that is somehow "armed" by the sequence
of
S1 moving from initial to opposite state and then triggers the
self-latching NC power relay when S1 returns to the initial state, this
should do it. If power first comes up with S1 open, then the trigger
arms
when S1 closes and triggers motor off when S1 re-opens. If power comes
up
with S1 closed, the trigger arms when S1 opens, and triggers when S1
re-closes. The end result is that the motor always stops at the SW
position after making at most one revolution. If you want the motor to
fall into always stopping when S1 closes, then you could a timer that
applies to the arming logic so that if S1 was open initially, but the
motor has run a minimum predetermined time, the trigger logic will fire
on
first closure.



Can't help but giving it a second look. I'm sure all simple solutions may
run into timing or exception problems like I said before. The solution
below
is not very simple but should work always.


+--------+---------+---------+
| | | |
| | | |
.-. _|_ _|_ _|_
( M ) |_/_|- |_/_|- |_/_|-
'-' |A |B |S
| | | |
| | | |
+----------------------+ |
| | | | |
| | | | |
| | | | |
| +--------o / o / o /
| | / / /
| | /a1 /a2 / SW1
| | o o o
| | | | |
| | +----+----+ |
| | | |
| | | |
o /o /o |
/ / |
/ b / s |
o o |
| | |
+-------------+------------------+--
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

S can be omitted when SW1 has a normally closed contact that can stand
the
motor current, so SW1 can replace the s-contact. If you have to use the
S-relay, it should be fast with respect to the A- and B-relays.

Well, maybe not for less hardware bux since the time delay relay is
kind of expensive, but since it'll surely eliminate the need for
grading the other relays in terms of speed, according to you,
there'll be some cost advantage gained there...

Which relays did you have in mind?


No particular relays in my mind. After alle I know too little about both the
power and the motor although it should work on mains supply if I've
understood well. As the S relay is only required to "invert" SW1, it should
be at least as fast as the others unless you can power it independently. If
that's the case it always reflects the state of SW1.

BTW. Using an (electronic?) delayed relay like you do makes me think about
another type of solution. FAIK mains relays are pretty expensive. Relays
that can switch mains power up to tens of amps using a 12V or 24V coil are
less expensive but need quite some low voltage power. What about building a
very small, low voltage, low current power supply and do it all in low
voltage electronics? The only power relay you need can be a solid state
relay which needs only 5V/10mA to switch on. Build a 5V/20mA power supply
and you can even use a PIC :) to do the thinking.

petrus bitbyter
 
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