Measuring AC Voltage and Current with the Basic Stamp
I need to monitor ac line voltage and current in device I am designing, the voltage will be either ~120v or ~240v depending on configuration, so I would like one solution that would work for both, as for current, I need to have a useable range of up to 50A (I assume that I will be using a Current transformer with a 200:5 ratio) (they are cheap)...
if either to voltage or current is above or below a preset threshold, I want to turn an output pin off (low)
Anyone have any ideas?
-Rich
if either to voltage or current is above or below a preset threshold, I want to turn an output pin off (low)
Anyone have any ideas?
-Rich
Comments
Gotta think for the low current issue. There's plenty of options, but not as straight forward as a 10 dollar relay.
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The stamp itself can't handle that kind of voltage so an external device would be needed to monitor line voltage.
Such a device could be purchaced with settable alarm outputs (dry contacts) to directly control things.
That's not to say that you "couldn't" route that signal into and back out of the BS2, but it would be wasting 2 I/O points.
Still not what you need, but I'm just thinking out loud.
Tommy
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I am wanting to use a basic stamp to control a large AC motor, this motor may be powered by either 120v or 240v line (i would love to have a single solution for both) this motor could draw anywhere between 10A-50A depending on size...
this motor will be in a hostile envirorment, and I want to protect this motor wich only runs 20% of the time...
if the ac voltage is either 30v above or below 120v or 240v whichever the case may be then I want to turn off the motor...
if the current draw of the motor is 20% above or below a set threshold I want to turn it off as well...
I am looking for a way to interface whatever I need to do to make this happen, I understand I will need an a/d chip, any ideas as to which one, and how to do what I want?
do I need something other then a stamp? perhaps a pic, or arm?
Check out this link, it will give you·info on what someone else did·to utilize a micro controller for a similar application:
http://groups.google.com/group/sci.electronics.design/browse_frm/thread/c406881489ff63ea/90317c3c7714b031?tvc=1#90317c3c7714b031
This one is·general info, not relating to micro control.
http://www.allaboutcircuits.com/vol_4/chpt_5/4.html
Hope that helps.
Tommy
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(Frequently heard from other's)
Tommy, I know it wasn't designed to·x, but can you make it·do x·anyway?
·