Please ALWAYS utlise proper isolation when playing with mains power supply. Burning your arduino and/or laptop in case the resisitve network fails may be trivial, but if you don't have ground current fault interrupter, or your mains does not have any isolation from the primary side, you risk electric shocks that could be fatal. Be careful!
How about a meter that shows voltage, current, real power, reactive power, apparent power and power factor? Is this possible? If yes please i wanted to know how to build one. It is so USEFUL!
I watched all your videos tutorials on building a multimeter, I wanted to make a voltmeter that can measure both positive and negative voltage and your videos really helped me a lot. I don't have a hobbyist and don't have any degree in electronics. Do have a forum where people like me can discuss their doubts or improve and ideate upon? Thanks 🙏
Wow that's a scary circuit. Only three small SMD resistors between the user and mains voltage. That's a recipe for disaster. I don't think you explained enough how dangerous this is.
Another great video Andrei. Your hand held multimeter just keeps getting better and better. I see the question of how to measure AC voltage with an Arduino come up from time to time in Arduino groups I belong to. This will now be the standard video I direct people to. Thank you for explaining this one. I'm looking forward to the new handheld multimeter version :)
Brother you can use Optocoupler for isolation, I have tested it has excellent linearity in LED current vs transistor current. So if you add a high value resistor in series with the LED, it will convert the voltage to current then you have to convert the current at the transistor side to voltage using a op amp. Then you will get a replica of the mains voltage. It will be half wave, since the LED is a diode. You can use double LED opto or 2 opto, or some software calibration for full wave reading
Hooking up such a non-isolated module to mains, with the Arduino connected to a laptop / pc is a bit reckless. If that module fails short, the Arduino will likely fail short too, and you will end up with mains voltages on the USB connection. In an isolated device, such a multimeter, you could (relatively) safely use this kind of circuit. But, this means the multimeter should have no USB port or other ground referenced / non-isolated connections.
I was looking for a module to replace the transformer type one, thank you! I'm trying to build a power meter that measure all that you've mentioned plus the direction of the energy flow, so I'm very interested on this topic. Thanks again, looking forward to have more knowledge from you!
I have an exciting proposal for a DIY lab bench multimeter using an STM microcontroller. I aim to enhance its functionality and precision by incorporating a separate selection switch for voltage, current, resistance, capacitance, and inductance, and utilizing a 12 or 16-bit ADC. I'd love to collaborate on this project and feature it on your channel.
This is UN-isolated measurement. With resistors providing a high impedance. The resistors that is used on the board might not be rated for the high voltage. If you want to use this design make sure your resistors are typically the HV range from Royal Ohm or the RCV range from Visahy. For handheld I would look IEC61010 for CATII or CATIII for the requirements.. Stay safe and keep designing.
In the multimeter voltage ranges are protected with MOVs and NTC's. Unfortunately your PCB doesn't have enough space or clearance to add high voltage measurement safely.
I would like to measure all the 24 circuits of my home - but not the voltage but the current. I dont want to have anything inline with my 32A 220 mains wiring, so my only option is these voltage transformer moduls with a split core. But even on Aliexpress they are 8 bucks plus shipping (or so) and for 24 this gets expensive. But I do not need accurate absolute reading, I only want to know which percentage of my power usage goes where. Can one DIY something like this?
@@ELECTRONOOBS For safety regulations reasons I cannot break the wiring or stick the sensor inline. And I would never trust Chinese made pcbs for not burning down my house. So I need something non invasive like a hall effect sensor or a wire wrapped arround the mains hot wire
That looks pretty complicated. I bought a meter off alibaba for $2.50 and its about as simple as it gets, but its accurate. It uses a current transformer and voltage divider that just feeds a micro that display to a 7 segment display.
you cant use a laminated transformer for this. you need a low reluctance ferrite one and you need to bias it with a permanent magnet or field to keep it in a linear region. Laminated transformers are not very linear and wont do well over 1khz, you will get something but it will be very atteniated
You need to stress that touching the live pads on the back of that little module will be painful. Placing that module on a bench with metal bits (component wires, tools, etc) could be spectacular! Please be careful!
Please ALWAYS utlise proper isolation when playing with mains power supply. Burning your arduino and/or laptop in case the resisitve network fails may be trivial, but if you don't have ground current fault interrupter, or your mains does not have any isolation from the primary side, you risk electric shocks that could be fatal. Be careful!
How about a meter that shows voltage, current, real power, reactive power, apparent power and power factor? Is this possible? If yes please i wanted to know how to build one. It is so USEFUL!
I watched all your videos tutorials on building a multimeter, I wanted to make a voltmeter that can measure both positive and negative voltage and your videos really helped me a lot. I don't have a hobbyist and don't have any degree in electronics. Do have a forum where people like me can discuss their doubts or improve and ideate upon? Thanks 🙏
Can you at-least try to explain the opamp circuit ? Anyone can hookup a module and download code from internet
Wow that's a scary circuit. Only three small SMD resistors between the user and mains voltage. That's a recipe for disaster. I don't think you explained enough how dangerous this is.
Another great video Andrei. Your hand held multimeter just keeps getting better and better. I see the question of how to measure AC voltage with an Arduino come up from time to time in Arduino groups I belong to. This will now be the standard video I direct people to. Thank you for explaining this one. I'm looking forward to the new handheld multimeter version :)
Thanks a lot! Also add a warning for working with high voltage ⚡⚡⚡ ;)
Brother you can use Optocoupler for isolation, I have tested it has excellent linearity in LED current vs transistor current. So if you add a high value resistor in series with the LED, it will convert the voltage to current then you have to convert the current at the transistor side to voltage using a op amp. Then you will get a replica of the mains voltage.
It will be half wave, since the LED is a diode. You can use double LED opto or 2 opto, or some software calibration for full wave reading
Hooking up such a non-isolated module to mains, with the Arduino connected to a laptop / pc is a bit reckless. If that module fails short, the Arduino will likely fail short too, and you will end up with mains voltages on the USB connection.
In an isolated device, such a multimeter, you could (relatively) safely use this kind of circuit. But, this means the multimeter should have no USB port or other ground referenced / non-isolated connections.
I was looking for a module to replace the transformer type one, thank you! I'm trying to build a power meter that measure all that you've mentioned plus the direction of the energy flow, so I'm very interested on this topic. Thanks again, looking forward to have more knowledge from you!
I have an exciting proposal for a DIY lab bench multimeter using an STM microcontroller. I aim to enhance its functionality and precision by incorporating a separate selection switch for voltage, current, resistance, capacitance, and inductance, and utilizing a 12 or 16-bit ADC. I'd love to collaborate on this project and feature it on your channel.
You calibrated for 220V AC, what happens if you measure another voltage and frequency for example from a signal generator.
This code can only measure symmetrical AC voltage, not pulses. It takes the peak voltage and divides it by root 2 to get the average value.
This is UN-isolated measurement. With resistors providing a high impedance. The resistors that is used on the board might not be rated for the high voltage. If you want to use this design make sure your resistors are typically the HV range from Royal Ohm or the RCV range from Visahy. For handheld I would look IEC61010 for CATII or CATIII for the requirements.. Stay safe and keep designing.
It would be cool if you will show how to measure AC current
Very useful 👌
great tutorial as always
Great video sir.... But including need to measure the real time frequency if possible to do.... ❤ please
thanks very useful !
I hope arduino 101 tutorial will be available soon!
I wish you would publish a link to BUY the sensors you feature in your videos.
In the multimeter voltage ranges are protected with MOVs and NTC's. Unfortunately your PCB doesn't have enough space or clearance to add high voltage measurement safely.
Hi, sorry I write here. I would send gcode from esp32 to an old CNC. Esp32--> db9 serial cable --> CNC. I need help. How can I manage rs232 protocol?
Hi the frequency in my country is 50 hz can use the same code?
I would like to measure all the 24 circuits of my home - but not the voltage but the current.
I dont want to have anything inline with my 32A 220 mains wiring, so my only option is these voltage transformer moduls with a split core.
But even on Aliexpress they are 8 bucks plus shipping (or so) and for 24 this gets expensive.
But I do not need accurate absolute reading, I only want to know which percentage of my power usage goes where.
Can one DIY something like this?
Use the ACS modules. There is one of up to 200A
@@ELECTRONOOBS For safety regulations reasons I cannot break the wiring or stick the sensor inline. And I would never trust Chinese made pcbs for not burning down my house. So I need something non invasive like a hall effect sensor or a wire wrapped arround the mains hot wire
That looks pretty complicated. I bought a meter off alibaba for $2.50 and its about as simple as it gets, but its accurate. It uses a current transformer and voltage divider that just feeds a micro that display to a 7 segment display.
cool video, thx
you cant use a laminated transformer for this. you need a low reluctance ferrite one and you need to bias it with a permanent magnet or field to keep it in a linear region. Laminated transformers are not very linear and wont do well over 1khz, you will get something but it will be very atteniated
You need to stress that touching the live pads on the back of that little module will be painful.
Placing that module on a bench with metal bits (component wires, tools, etc) could be spectacular!
Please be careful!
Why resistive divider in AC ?, why not capacitive voltage divider?
Because its internal resistance does not depend on frequency. If used, its accuracy is not equal to the resistance.
cap performance can be frequency dependent
Could you please help me with the link where I can buy this module
Hello
can you make a video about how to drive zmpt101b in Arduino?
I can't find a diagram for this module MCP6002, what is its name?
Please 🙏 Link to get the MCP6002 module
It looks like that mcp6002 module have no galvanic isolation 😥😥😥😥
Make a magnetizer
Safe.... That module does not look like it's safe: i don't see neither MOVs nor isolation gaps, component quality is at a question...
😀
First
Is it possible to measure 1khz Ac (10v to 50v) ??