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Discussion Starter · #1 ·
Simple:
110VAC --- Plug --- Device1

The device draws essentially no current, but when it does, how can its current trigger a secondary relay? Like this:

110VAC --- RelaySensorModule --- Plug --- Device1
|
|____________ Device2


...so that the sensor module is a passthrough for the 110VAC for Device1, but Device1's draw closes a relay, or somehow provides a logic 0 or 1 level, which can be used to activate Device2.

The relay/sensor module for Device2 is merely detecting when Device1 is running or not, and when it's not, Device2 is off. When Device1 is running, Device2 runs, too. I need to keep the two circuits separate. One will be 110VAC, the other will be 12VDC.

Reed switch?

Coiling the 110VAC cord around a ferrite core?

Thoughts?

Thanks.


 

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I would use 2 relays in series for the coils. Then each of the relays, use the contacts for each device. Sometimes you can find a relay that will handle both AC and DC for the contacts but you will need atleast 2 sets of contacts.
 

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black light queen
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a relay with normally open and normally closed contacts might do what you want

normally open contacts look like this -II- ... the relay should have that symbol or will just show NO

normally closed contacts look something like this -I/I- or will say NC

device1 uses 120vac, so you have a relay with a 120vac coil in parallel with the power to device1 ... the relay will turn on when device1 is also turned on

for device2, which is 12vdc, you run the 12vdc through the NO contact in the relay and to device2
something like this
positive12vdc -----I/I-----device2------negative12vdc

120vac-----device1-----neutral120vac

120vac------120vac relay coil-----neutral120vac

hope that my crude diagram above makes sense

amk
 

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Is 120v constantly supplied to device1 or only when it is "on"? By your explaination I'm assuming device1 has constant power but is somehow internally triggered to turn on. If this is the case then a simple parallel 120v relay won't work, hence you need something to detect the current flow. It would help to know what "device1" is.
 

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Discussion Starter · #7 ·
This makes sense. There are some for sale on ebay with, uh, Australian socket design. I with there were some North American socket designs.

Some of them are listed as power strips, some are listed as surge protectors.

The other answers make sense too. I could use them in my prototypes, but it'd help if it were commercial-off-the-shelf. So David_AVD's suggestion about a master slave power board so far is the easiest route.
 
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