An IC that can switch a 120V power source?

I'm looking to create a simple circuit that uses standard 5V ICs, one of which I can use to control a standard 120V/60Hz AC power line. I know these kinds of voltages are dangerous, so I would like something that includes some kind of protection (e.g. the components are all sealed).

I'm also looking for something that can take the same 120V power and provide a 5V DC supply for my circuit.

I'm trying to create a circuit that uses a 555 timer to control a 120V light bulb, and I want to interface that with a standard light switch. Since I don't know what kind of device this IC would be called, google isn't helping me.

Reply to
Timur Tabi
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It is called a "solid state relay." I would also advise that you think very carefully before rejecting the idea of using a good old fashioned electromechanical relay.

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Guy Macon
Reply to
Guy Macon

For turning AC mains on or off via 5V logic, you want either a relay or a solid-state relay.

Powering the circuit from the mains requires a PSU; search for "encapsulated PSU" if you want a sealed unit.

Reply to
Nobody

There are a number of application notes on line-powered micro- controllers, usually falling into either entirely resistive or mixed resistive/capacitive. Some of them cover the inclusion of MOVs and snubbing circuits for switching noise moving out of the circuit and into the line, as well. (Zero crossing comes nearly for free in either -- keeping in mind phase in the case of capacitive dividers to choose the tap off point wisely.) A comprehensive study might be worth the effort required.

Here's a quick couple I just found after using google:

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Jon

Reply to
Jon Kirwan

I have an idea but I only have time to make a parts list:

1 12V wallwart. 1 bridge rectifier 1 200V mosfet 1 opto isolator

D from BC myrealaddress(at)comic(dot)com BC, Canada Posted to usenet sci.electronics.design

Reply to
D from BC

You should be glad not to have to deal with 220V. 120V can hurt, but

220V can kill.

You still have to wire the connections. After getting a couple of shocks, I insulated all live (120V) connections and wires with fire retarded hot glue. The glue will not burn even if ignited.

I took the board out of a plug in wallmart to power the uC and relay.

That what's I did. The only thing to consider is the life cycle, probably several hundred thousands on/off.

For my hot water switching regulator, it comes on at day break (with photo sensor) and on and off during the day (with temperature sensor). So, I figure up to 100 cycles per day or several years of life. In a few years, I would probably replace the relay, transistor and pump anyway.

See:

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Reply to
linnix

Can you tell me more about this kind of glue? Do you know of a brand name?

Reply to
timur.tabi

I got some from China years ago. I don't have any more information on it. If you burn it with a lighter, it will turn black but not ignited. I think it is similar to materials in FR-4 (Fire Retarded #4) PCB.

Reply to
linnix

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