switching device 2

[un421ate1]

Apologies if this duplicates an earlier request.
Require a four input one output solid state switching device that switches on only when all inputs (120vac)are present and remains on when all or only one input is present and switches off when no inputs are present.
If someone can direct me to a manufacturer of such a device (with model numbers) will be really really grateful.

 

[VEBill]

Sounds like a unique requirement.

To clarify, the four input signals are 120vac, and the output is what? A dry contact? Or 120vac?

 

[jraef]

Do you want a board level IC, or a logic device that you can mount and wire into a control panel?


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[un421ate1]

thanks for response
Output can be either a dry contact or 120vac
Thought maybe someone manufactured a programmable plug in
DIN rail mountable device.
Salesman from SSAC said only option he could think of would be a micro PLC.

 

[Compositepro]

It would be easy with five double pole electromechanical relays. Why must you use solid state for 120 vac?

One latching output relay with four input relays. One set of contacts from each input relay in series with the coil of the output relay performs the AND function.

One set of contacts from each input relay in parallel with each other and in series with the latching contact of the output relay will keep the output latched until all input are off.

 

[VEBill]

Compositepro has nailed it, and explained it clearly.

The only clarification needed is that the latching relay will need its own separate power supply, OR additional circuitry (perhaps switching and logic) would be required to chase the available 120vac across the four inputs.

 

[un421ate1]

Thanx Compositepro
terrific suggestion and will probably use your idea.
problem is space considerations...was hoping someone made a programmable plug in miniature device....but guess not.

 

[jraef]

I would use a simple little "Smart Relay" like the Siemens LOGO! product. Usually less expensive than 4 DPDT relays plus a latching relay. The cheapest ones have 8 inpits and 4 outputs. That way if you made an error of omission in your requirements you have some room to add something too.


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[un421ate1]

jraef
many belated thanx for info