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[David Allred]

I put together a triggering system for a fog machine.  2 sets of photo sensors trigger a timer / relay (set to give three 2 sec pulses 1 minute apart then wait for another trigger).  The relay is connected to fog machine remote input (1/4 TRS).  The Ring & Sleeve are factory connected to the manual button on the fogger.  So whether the manual button is pressed, or the Ring & Sleeve are shorted, the fogger fogs.  This has worked as designed on a daily basis for a several of years now.
A 2nd TRS has been paralleled to a 2nd fogger with an odd result.  The original fogger is an ADJ Fog Fury 2000, the added fogger is an ADJ Fog Fury 3000.  They both use the same wired remote that connect the Ring & Sleeve to fog.
Everything works as expected.... unless either fogger is turned off or is in warm-up mode.  All foggers are on programable outlet timers that cycle to have 30 min cool down periods every 4 - 5 hrs.  The cool downs are offset so that there are always at least 2 foggers on and ready.  When one of the 2 foggers on this circuit is powered down by it's outlet timer or goes into heat mode, the other fogger fogs continuously. 
My first thought was the chassis were grounding together through the building so I tried a ground lift plug on one to test, with no change.  I checked to see it the Sleeve was grounded to the chassis, but it was not.
I reversed the wires connecting the Ring & Sleeve on each run, individually, with not change.  Both foggers have pump shut-off for low fluid and obviously the pumps won't pump if not heated.  The TRS remote inputs and manual buttons go to the fogger controller, not connected directly.
It sounds like the "manual activation" relays in the foggers are normally closed?  That works for OFF, but that makes no sense during heat-up.

Any ideas what is happening?  Any ideas for a work-around?  Trying to avoid buying a 2nd timer relay. 

Thanks.

[Steve-White]

Circuitry "logic" state changes in standby, heating or off.  They probably apply a low DC voltage to the relay coil and the switch grounds the other side of the coil (drops a low) to activate the fogger.

I would setup a control relay for each fogger controlled by the timer to isolate them electrically from one another.  Having them connected together, and manifesting the condition they exhibit it's probably best to not operate them like that as it could damage circuitry.

[Scott Helmke]

Perhaps the off/warmup state is to allow an indicator on the remote?

Anyway, separate outputs to isolate them from each other is probably your best approach.

[David Allred]

I would setup a control relay for each fogger controlled by the timer to isolate them electrically from one another. 

Like this?

[Steve-White]

^^^ Not quite.  I wasn't sure what powered the timer circuit.  Use 110V primary relays, power primary's of them through the switched relay in the timer in parallel.

For only two foggers a single DPST relay is all it would take.  Double pole single throw relay - simple on-off that's isolated between the foggers.

Or used two SPST single pole single throw relays.

Judging by your drawing you can draw up and understand the circuit.  Have a go at it and post it up for a look.  Keep the primary switching circuit of the relay(s) from the timer isolated from the foggers.  On the switched side of the relay(s) keep the foggers isolated from one another.

[David Allred]

^^^ Not quite.  I wasn't sure what powered the timer circuit.  Use 110V primary relays, power primary's of them through the switched relay in the timer in parallel.

For only two foggers a single DPST relay is all it would take.  Double pole single throw relay - simple on-off that's isolated between the foggers.

Or used two SPST single pole single throw relays.

Judging by your drawing you can draw up and understand the circuit.  Have a go at it and post it up for a look.  Keep the primary switching circuit of the relay(s) from the timer isolated from the foggers.  On the switched side of the relay(s) keep the foggers isolated from one another.

I clarified the drawing a little.  https://www.ebay.com/itm/383717042975?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2763.l2648 This is the timer / relay in use.  The added relay is an RH2B-AC110v-120v Idec a have available.  Using the Timer's output relay to power the coil of the Idec.  Each pole of the Idec is closing the Ring & Sleeve of the connected fogger.  You may have interpreted the relay as powering the 2 foggers.  It was a pour representation of the push button / manual circuit.
Am I correct now?

[John Roberts {JR}]

Don't ASSume because they use the same remote switch, their circuitry is the same.

It seems that separate fully isolated relay contacts should work to provide switch closures without interaction.

JR 

[Russell Ault]

{...} Am I correct now?

I don't think so. Both your diagrams have the sensor power run in series with the coil for the secondary relay, which is almost certainly not what you want because (a) running anything in series with a relay coil is likely to result in unexpected behaviour (unless you really know what you're doing) and (b) it means your sensor will only have power when the foggers are running.

I should also add the usual caveats about playing with line power: please don't kill yourself, and if this starts a fire it's not my responsibility (and, incidentally, your insurance company might say the same thing).

-Russ

[David Allred]

I don't think so. Both your diagrams have the sensor power run in series with the coil for the secondary relay, which is almost certainly not what you want because (a) running anything in series with a relay coil is likely to result in unexpected behaviour (unless you really know what you're doing) and (b) it means your sensor will only have power when the foggers are running.

-Russ

The timer and the sensor are powered by a parallel 110 line feed (plugged into the wall).  The 110 line is also tied to the common of the relay.  The NO output, when closed, feeds the line side of the secondary coil (load).  The neutral side of the 110 to the secondary coil is tied to the timer's and sensor's 110 neutral feed.  The timer's relay NO (line) and direct connect to neutral switches the secondary relay coil.

[Steve-White]

I clarified the drawing a little.  https://www.ebay.com/itm/383717042975?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2763.l2648 This is the timer / relay in use.  The added relay is an RH2B-AC110v-120v Idec a have available.  Using the Timer's output relay to power the coil of the Idec.  Each pole of the Idec is closing the Ring & Sleeve of the connected fogger.  You may have interpreted the relay as powering the 2 foggers.  It was a pour representation of the push button / manual circuit.
Am I correct now?

The guys are all explaining it correctly.  This diagram looks nice, not technically with the circuit, but visually.

So, please send this version only in the form of the CURRENT WIRING and then we can tell you where to insert the auxiliary relay(s) primary.  The NO switched part of the relay(s) will be separate ring/sleeve circuits for each fogger.

You'll get this figured out soon.  The relays are for switching with electrical isolation.

[David Allred]

So, please send this version only in the form of the CURRENT WIRING and then we can tell you where to insert the auxiliary relay(s) primary. 

This is the the current entire circuit. 

[Steve-White]

Get yourself a DPST relay with a 110V primary and 1A or so for capacity for use as auxillary switching or isolation.  Wire one side of the coil to the line-in neutral, route the L1 or hot side of the line to the common on the relay on the control board.  The NO side of the relay will go to the other side of the auxillary switching or isolation relay.

Use the NO contacts independently for each fogger.

[Steve-White]

Don't ASSume because they use the same remote switch, their circuitry is the same.

It seems that separate fully isolated relay contacts should work to provide switch closures without interaction.

JR

And even if the circuitry was exactly the same is no guarantee that any of the units could share common control circuitry.  Even the same model may or may not be able to work in tandem off of a common switch.  Ya just never know without a schematic.

[David Allred]

Get yourself a DPST relay with a 110V primary and 1A or so for capacity for use as auxillary switching or isolation.  Wire one side of the coil to the line-in neutral, route the L1 or hot side of the line to the common on the relay on the control board.  The NO side of the relay will go to the other side of the auxillary switching or isolation relay.

Use the NO contacts independently for each fogger.

Thanks.  That confirms what I thought.

[Steve-White]

Thanks.  That confirms what I thought.

Layout your circuit and let us have a look to assist you.

[Luke Geis]

The issue I see is that if there is any kind of voltage or feedback loop in the switch circuitry of the machines, then having both the switches tied together will allow this feedback or voltage transfer to occur between them. I would be looking to make a circuit that utilizes optocouplers, or vactrols. The idea is to break the physical connection between the devices, but yet still have the switching control signal exist in any one of the two lines. I.E. the vactrols turn off one of the unused devices switch, thereby taking it out of the physical loop.

[Steve-White]

A simple DPST NO relay will provide 100% electrical isolation which it appears in this case to be necessary.

[David Allred]

Layout your circuit and let us have a look to assist you.

Your detailed description... "Get yourself a DPST relay with a 110V primary and 1A or so for capacity for use as auxillary switching or isolation.  Wire one side of the coil to the line-in neutral, route the L1 or hot side of the line to the common on the relay on the control board.  The NO side of the relay will go to the other side of the auxillary switching or isolation relay.
Use the NO contacts independently for each fogger." ... followed my drawing to he tee.  Here is the slightly clarified layout.  Thanks for the help.

[Steve-White]

^^^  Had to look again.  You are right, I misread the relay block.  Sorry sir.

I misread pins 1 & 8 on the relay as dual primary's and not the common for each side between the NO/NC contacts.

Perfect.

Let us know how it works.

[ProSoundWeb Community]