All Questions
12 questions
2
votes
5
answers
278
views
How to sense the presence of AC voltage that could vary from 17 V to 230 V?
I have a requirement to sense the presence of AC voltage, that could vary from 17 V to 230 V, and trigger a TLPxxx series optocoupler.
The wide voltage range poses a problem in the choice of a ...
2
votes
4
answers
3k
views
Op-amp use in voltage sensing
For voltage sensing, we use a resistor divider and then we always feed that value of the resistor divider to an op-amp and then the op-amp output is fed to a microcontroller.
What exactly does the op-...
- 357
1
vote
1
answer
666
views
Check for live high voltage shielded three phase conductor
We would like to know if a shielded high voltage cable 8000V AC, 3 phases, is "live". Whether there is current flowing or not.
Ideally we design a little device that's strapped around the cable (...
- 379
0
votes
2
answers
644
views
Differential Opamp Strange Behavior
I have no answer for this strange opamp behavior. The circuit shown is from a typical non-isolated, non grid-tie inverter product (imagine H bridge inverter), which has a common -Ve high power circuit ...
0
votes
0
answers
535
views
Sensing AC voltage
In a project I'm working on (Totem pole PFC) I need to sense the input AC voltage, scale it down, rectifing it/adding an offset and then send to the ADC of the digital controller to use in the control ...
- 139
1
vote
1
answer
545
views
Sensing high differential voltages using operational amplifiers
Is there any solution to sense high differential voltages using operational amplifiers (without using resistive voltage divider) ?
The input voltage range is [-30, 80] Volts.
I've searched on all ...
1
vote
1
answer
2k
views
Voltage sensing using Arduino with and without common reference
I wish to make a voltage sensing circuit (range -15V to +15V) using an Arduino's ADC. The problem is that since this circuit will be part of a much larger circuit in which the Arduino is performing ...
- 47
0
votes
2
answers
3k
views
Detect if input voltage is 110V or 230V signal
I'm building a small electronic project that will measure the power consumption of a device and send this back to Arduino or ESP2866.
I've figured out how to measure the current that goes trough a ...
- 123
1
vote
2
answers
91
views
Determining which power supply is connected to our circuit?
I am designing a small dongle that will have features either enabled or disabled as a function of the supply voltage. I want the device to be low-power and run, for the most part, off a 3V coin-cell ...
- 3,461
2
votes
1
answer
2k
views
Current, Voltage, and Power Sensing for 115 V AC Circuits
I am trying to sense voltage, current, and power with an Arduino (Due) for monitoring and diagnostic applications. To get reasonably good input (better than Kill-A-Watt), I have designed an AC sensing ...
- 173
1
vote
1
answer
570
views
Can I Use Current Sensing Transformer Instead of Power Transformer
This is a follow-up on this question:
How to Design Arduino Voltage and Current Sensing Shield
Thanks to user bigjosh, I read the article:
http://openenergymonitor.org/emon/buildingblocks/measuring-...
- 173
0
votes
1
answer
686
views
Relay that detects 240VAC and switches 12V DC
I'm wishing to detect the loss of AC power (in this case 240V) and when this event occurs have a 12V DC circuit go to earth. This will trigger an alarm for users to react to situation.
Can anyone ...
