WANNA CHALLENGE?
Try and find an adjustable high and low voltage 120vac alarm? I can't even find an outage alarm for use with UPS that gives a discreet "chirp" every so often when on battery.
Forum Discussion
MEXICOWANDERER wrote:
Oh yeah I messed up royally. The complexity was for an under/over voltage alarm not the power outage alert. And I failed to keep the two well separated in my posts. A tablespoon of salsa habanero and slap on the back to make me cough..
It's the blipping sonalert that is less than easy to come up with. A chirp interval slower than every 10 seconds but faster than every thirty seconds.
I want a gentle alert, not a banshee shriek that swami levitates me a foot off the bed. And I will definitely screw up and leave the thing plugged in and I do not want to waste a six dollar battery having the device advise the cucarachas that nobody's there, so form a conga line.
Wall wart, Capacitor, relay with chirp circuit for piezo Annunciation. Might even go with a white blinking LED.
The home made voltage alarm circuit is available but I need a 120/12 transformer, lots of zener's and transistors I do not have. And a stupid piezo.
Sonalert now days refers to most any noise making devices..
You can get piezo "buzzers" if you will for peanuts and a simple $1 9V drycell could run it for a month since they don't use much more than 5 ma or 10 ma..
HERE
MORE BUZZERS HERE
Circuit would also be self resetting and unless you are having power outages for hrs on end there is no reason a battery would be used up fast..
For over/undervoltage monitoring you can make a "comparator" circuit using a "op amp" a few resistors..
Kind of looks like..
Where you adjust the voltage level the LED lights (or buzzer buzzes or relay changes status) using VR1..
With two of that circuit one can be set to detect high voltage and the other for low voltage..
I made a cool LED "VU" meter years ago using the same circuit just adding more Op amps and setting them to the correct voltage for each DB level I wanted to display.. Cheap and effective.
You could use a unregulated wall supply or a AC output wall supply and make your own ac to DC power supply..
Folks now days are used to over complicating the simplest of tasks..
