I have lots of items I wish to monitor via eyesight at night. Like power to a pump 200' distant with bare rock in between. Power to the gen shed with 300' in between me and the devices. Yeah I could do it with relays, voltage buckers, etc. etc. But some of these things are outside and I don't feel like spending a fortune on larger project boxes and wiring stuff up.I can see a 3.2 volt 20 ma blinking green LED at night even at 300' The BREAKERS are a 70' walk sometimes through driving rain to a NEMA 4 enclosure. The gen shed has it's own service service drop.A power outage monitor is easy to configure for inside. But not so easy for the outside stuff. And I have indeed lost service multiple times to several critical outside devices. And not known it.That's the justification for the work...I would like to use plastic handy boxes, sealed up, with nylon blank plates drilled for a 5 mm LED holder.Also inside the box would be a 7K 5-watt ceramic resistor. I have a bunch of everything listed here and a chance to order whatever and get it down here next month. I do not want to spend a King's Ransom on this.Is there any problem with the ceramic resistor / enclosed 12 volt blinking LED combination?Call it a wireless power outage indicator.

Skip that huge resistor, use a capacitor to sneak a little current from the AC mains, like the Honorable Chinese engineer do for the line powered LED bulbs from fleabay... http://www.marcspages.co.uk/tech/6103.htmhttp://www.eeweb.com/blog/extreme_circuits/mains-operated-led-circuit-schematic

Not sure what kind of load you're going to have on that 5 watt resistor, but a few years ago I enclosed a 4 watt night light in a 4" x 6" x 8" wood box to protect an alarm circuit box from sub-zero temps out in a remote shed.To my surprise it failed because it got too hot in the box. I couldn't tell exactly, because it pegged a 120 degree thermometer. I ended up leaving the lid about half open. That still gave me a 30 degree temp boost, which was all I needed.Another project - right now I'm using a 1/2 watt 1K resistor in series with a 12V flashing LED connected to a 12 5AH battery. The battery lasts about 6 weeks with the resistor or less than 2 weeks w/o the resistor. Can't really tell any difference in brightness either way.

As alluded to in the marcspages link, a blinking LED often wouldn't like the applied voltage going to zero periodically and has a nonuniform power consumpotion. With the mains dropper resistor approach, you'd still likely need a rectifier and capacitor and zener or other crude regulator to give it something resembling continuous power.Do the LEDs work on 5V? If so, I'd be mighty tempted to hook up a generic cell phone/USB charger doohicky as the power supply (probably with a fuse to ease the paranoid mind).

I have all the stuff here and as an intermittent 20 ma 2.2 volt load is involved I wonder how much heat will actually be involved?The LED is manufactured as a blinking device, and a dropping resistor is already built in. These gizmos are dug out of an old box. So the huge resistor is to merely drop voltage to a level presentable for the 12-volt device to work. It all has to fit inside a duplex box (of which I have a case), and the Nylon blanks can be easily drilled. I wondered what the capacitor service life would be as these are 24/7/365 devices. I know the ceramic resistor would live virtually forever but how about a cap?And a million thanks for the link Gordon Three. I am going there right now as they point to fresh meat info.

If you're using a series regulator (of which the dropping resistor would be a crude version), your power dissipation would be the line voltage times the average current, assuming a unity power factor--which the dropping resistor provides. So if we assume a 50% duty cycle 20mA setup, the power dissipated is about 1.2W--certainly enough to get rather warm. If it's 20mA average, then of course double the power consumption.Basically, the LED would be dissipating whatever voltage it's running at, and the resistor the rest to reach the line voltage. The vast majority of the power dissipated is by the resistor--90% if the LED is running at 12V.You still have to convert AC to DC for the LED somehow, and regulate the voltage it sees when it's off. (Off or reverse biased implies virtually no current consumed, which implies its instantaneous impedance is high, which means the voltage divider with the dropping resistor makes the LED subject to nearly the full line voltage. I predict it would very soon be permanently off.)I'm reminded of the old cheaper tube radios and TVs that used a mains dropping resistor to control current through the heaters. There are good reasons why a filament transformer was preferable and safer, some of which would also apply here. Those dropping resistors often didn't hold up so well over long time use--maybe modern ceramic resistors are more robust.

Blinking 12 volt LED With 120 vac Power Supply?

NinerBikes
Explorer
Dec 05, 2015
MEXICOWANDERER wrote:
Niner

Stick it in a big pot.

Boil the water until the lobster turns red

Extract it with tongs

Let cool

There is a large amount of meat between the antenna on the head

Old Bay seasoning, 2 heaping tablespoons in the boiling water makes it more yummy.

Niner, yer gettin' a killer transient voltage killer when In get north. Have not been north since April.

I was just teasing, I expect nothing, except maybe meeting The Legend in person some day.
MEXICOWANDERER
Explorer
Dec 05, 2015
Niner

Stick it in a big pot.

Boil the water until the lobster turns red

Extract it with tongs

Let cool

There is a large amount of meat between the antenna on the head

Old Bay seasoning, 2 heaping tablespoons in the boiling water makes it more yummy.

Niner, yer gettin' a killer transient voltage killer when In get north. Have not been north since April.
Canadian_Rainbi
Explorer
Dec 05, 2015
Gordon, I envy you. Mexicowanderer is in your debt. For too many of us it is the reciprocal. :B
NinerBikes
Explorer
Dec 04, 2015
MEXICOWANDERER wrote:
YAHHHH!

Just ordered ten! Forever grateful! Too bad I cannot send you, say, ten or fifteen lobsters.

LOL, if you EVER send me a lobster, there better be instructions on how to prepare it. ;)
NinerBikes
Explorer
Dec 04, 2015
GordonThree wrote:
MEXICOWANDERER wrote:

I sure wish there was a wireless way to monitor multiple circuits for outages. The one's I glanced at were worth more than my car. :( My son-in-law has about $8,000 worth of lobsters and red snapper stored in the three freezers.

There's a little gem called the ESP8266, hot item right now from China. It is a microcontroller with a WIFI radio built in. The tools to program them are a $5 USB serial cable and a free download from the Internet. Best thing? They're about $3 each at qty 10.

Connect to the N/O contacts of a line powered relay and presto, chip turns on when the power goes out. Have one more back at the ranch listening, with a big buzzer connected.

Excellent share there, Gordon! Thanks again!
GordonThree
Explorer
Dec 04, 2015
MEXICOWANDERER wrote:
YAHHHH!

Just ordered ten! Forever grateful! Too bad I cannot send you, say, ten or fifteen lobsters.

Woohoo! Feel free to pm me or ask in the forums if you need help getting started with them.
MEXICOWANDERER
Explorer
Dec 04, 2015
YAHHHH!

Just ordered ten! Forever grateful! Too bad I cannot send you, say, ten or fifteen lobsters.
GordonThree
Explorer
Dec 02, 2015
MEXICOWANDERER wrote:

I sure wish there was a wireless way to monitor multiple circuits for outages. The one's I glanced at were worth more than my car. :( My son-in-law has about $8,000 worth of lobsters and red snapper stored in the three freezers.

There's a little gem called the ESP8266, hot item right now from China. It is a microcontroller with a WIFI radio built in. The tools to program them are a $5 USB serial cable and a free download from the Internet. Best thing? They're about $3 each at qty 10.

Connect to the N/O contacts of a line powered relay and presto, chip turns on when the power goes out. Have one more back at the ranch listening, with a big buzzer connected.
Chris_Bryant
Explorer II
Dec 02, 2015
MEXICOWANDERER wrote:
Unreliable to the point of absurdity. Simple 1-amp diode and 1/8th watt resistor. I purchased a dozen two years ago. None are left.

I've only opened one that died, but I have probably a dozen or so that are years old, running 24/7- most are candelabra base bulbs. They give 50,000 hour life, some have well over 150,000 hours (that's not that long, actually).

Or something like this led bulb, or any of these. I looked at LED beacons, which are available, but being weatherproof and industrial, they run $20 and up. You can get them in flashing, rotating or steady, and any color.
MEXICOWANDERER
Explorer
Dec 02, 2015
Unreliable to the point of absurdity. Simple 1-amp diode and 1/8th watt resistor. I purchased a dozen two years ago. None are left.

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