In the "How to build an arduino energy monitor - measuring current only" guide it doesn't show what supplies power to the breadboard or the Arduino.
I noticed that when I plug a USB into the Arduino it lights up but when I put the red wire from the breadboard to the Arduino like the guide says it turns off.
Im assuming it does this because it detects a wire onto the 5V pin and switches from usb power to that for power but nothing is powering the breadboard so Arduino turns off.
Re: How do I power breadboard/arduino in the "How to build an arduino energy monitor - measuring current only" guide????????????
it doesn't show what supplies power to the breadboard or the Arduino.
The Arduino powers the breadboard. That's what the red wire you mention does. If the Arduino "turns off" when you connect that, it probably means you have a fault on your breadboard that is overloading the USB supply and it is shutting down to protect itself. You need to very carefully check your wiring.
Re: How do I power breadboard/arduino in the "How to build an arduino energy monitor - measuring current only" guide????????????
Thanks for the response.
What on the breadboard needs power? All that is on the breadboard is a CT that produces a .333V as an output to the Audrino.
Re: How do I power breadboard/arduino in the "How to build an arduino energy monitor - measuring current only" guide????????????
Wrong on two counts. (a) The c.t. burden should produce around 1.75 V rms at maximum current in order to use the full input range of the Arduino (and so get maximum accuracy particularly at low currents) and (b) you've forgotten the bias components. Read up in Building Blocks here on why that is necessary.
Re: How do I power breadboard/arduino in the "How to build an arduino energy monitor - measuring current only" guide????????????
Ahhh got it. You are the man.
So basically you supply power to the breadboard for when the AC voltage from the CT alternates to negative it fills in a positive of equal value since Arduino only wants positive voltage as input?
Thank you for the help, I know how it is talking to noobs.
Re: How do I power breadboard/arduino in the "How to build an arduino energy monitor - measuring current only" guide????????????
So basically you supply power to the breadboard for when the AC voltage from the CT alternates to negative it fills in a positive of equal value since Arduino only wants positive voltage as input?
Not quite. It lifts the whole of the wave that is balanced about zero so that it sits at half the supply, so then it is all positive.
Re: How do I power breadboard/arduino in the "How to build an arduino energy monitor - measuring current only" guide????????????
Thanks again and Holy crap it works!!! Well kinda.
Im getting 6 amps read on serial monitor and 8 amps on my handheld amp probe.
Note that im located in the USA. Am i using wrong resistor/capacitor size? Or is it something in the code?
Re: How do I power breadboard/arduino in the "How to build an arduino energy monitor - measuring current only" guide????????????
You need to read through the article on calibration (in Building Blocks) and check the current calibration constant. If you have a reasonably accurate clamp ammeter, then probably the best way is forget the theory and adjust the calibration constant so that it reads the same as your meter. If you have the correct resistor values, 25% low is rather a lot (more than I can account for with component tolerances) so read through the theory and check the numbers. That might show up an error somewhere. 111.1 assumes a 100A : 50 mA c.t. with an 18 Ω burden resistor.
Re: How do I power breadboard/arduino in the "How to build an arduino energy monitor - measuring current only" guide????????????
As Robert mentioned, I believe you just need to calibrate your device to get better results. Follow the instructions on this site by comparing to a calibrated meter, here's a graph one of my emonTx devices during a calibration check. The x-axis shows the wide range of current across the SCT-100A using two settings on my fiance's blow-dryer, and making multiple turns of wire to multiply the current seen by CT. The y-axis is % Error compared to my Kill-a-Watt meter.
Your resistors/capacitors should work just fine if your followed the instructions on this site. I live in Canada so the highest difference was the 120V, which you need to get another AC transformer and use a calibration closer to 119.5.