[Gigs]

I'm looking for a cheapish consumer device to keep the power off after a power failure.

My stereo receiver defaults back to AM Radio when the power comes back on, and it blasts very loud static until someone turns it off.

It hasn't yet done it in the middle of the night but I can imagine it will sometime soon.

I know I could get a UPS or whatever, but that still wouldn't solve the problem if the power is off for more than a little while.

 

[Matsukaze]

A manual reset portable GFCI will do what you want. These are used with portable power tools on construction sites. You should be able to get one for around $30-$40 at Home Despot, Lowes, or a similar store. Be sure to get the manual reset kind; there are also automatic reset units which will reset by themselves when the power comes back on.

 

[InPhase277]

Not sure of an off the shelf product, but I could think of a couple of solutions. One would be to use a double pole relay, where one pole is used to make the circuit to your equipment, and the other pole is actually used to complete the circuit that energizes the relay. In other words, when the coil is energized, it is self-latching. When the power fails, the coil will unlatch, and will not re-latch until you manually reset it (a momentary push button).

 

[Scuba_Dave]

That's weird, I've never had any stereo that turns on by itself
We have one on a power strip that we keep shut off due to the fact the display is bright

 

[Gigs]

That's weird, I've never had any stereo that turns on by itself
We have one on a power strip that we keep shut off due to the fact the display is bright

We leave it on because normally it's just feeding from the TV as a source. The problem is after the power blinks, it resets the source to AM radio.

 

[Gigs]

A manual reset portable GFCI will do what you want. These are used with portable power tools on construction sites. You should be able to get one for around $30-$40 at Home Despot, Lowes, or a similar store. Be sure to get the manual reset kind; there are also automatic reset units which will reset by themselves when the power comes back on.

Very cool, I will look into that.

 

[Gigs]

Not sure of an off the shelf product, but I could think of a couple of solutions. One would be to use a double pole relay, where one pole is used to make the circuit to your equipment, and the other pole is actually used to complete the circuit that energizes the relay. In other words, when the coil is energized, it is self-latching. When the power fails, the coil will unlatch, and will not re-latch until you manually reset it (a momentary push button).

Yeah, I thought about that solution. It's well within my capabilities to make such a thing. I'm just not sure I want to trust something I built that's line powered and sitting in a mostly hidden place near dust and carpet. If I can buy something UL listed instead for not much money then that would probably be less stressful.

 

[Yoyizit]

Not sure of an off the shelf product, but I could think of a couple of solutions. One would be to use a double pole relay, where one pole is used to make the circuit to your equipment, and the other pole is actually used to complete the circuit that energizes the relay. In other words, when the coil is energized, it is self-latching. When the power fails, the coil will unlatch, and will not re-latch until you manually reset it (a momentary push button).

Power failures would make my analog clocks read the wrong time so I made one of these in the late 70s. That way I knew the power had failed. To reset, you pushed the relay armature back into the 'on' position through a hole drilled in the relay case, with a toothpick.
I have the schematic somewhere; for some reason I used a relay with a very high coil resistance - 5k - and a large capacitor.

Parts cost ~$7. Labor, a morning.

 

[InPhase277]

Yeah, I thought about that solution. It's well within my capabilities to make such a thing. I'm just not sure I want to trust something I built that's line powered and sitting in a mostly hidden place near dust and carpet. If I can buy something UL listed instead for not much money then that would probably be less stressful.

HAHAHA! I know what you mean, but me personally, I'd trust the device I built to known standards. The UL label just means someone paid enough money to get it. If you have seen some of the UL listed stuff that comes from China you'd know what I mean. Good luck.

 

[Yoyizit]

My "UL listing" was to put the circuit in a metal outlet box.

The UL label just means someone paid enough money to get it. If you have seen some of the UL listed stuff that comes from China you'd know what I mean. Good luck.

The UL = ?
"Regulatory capture is a term used to refer to situations in which a . . .regulatory agency created to act in the public interest instead acts in favor of the commercial or special interests that dominate in the industry or sector it is charged with regulating. Regulatory capture is a form of [agency] failure . . ."

How could such a thing happen, here in America???