mains /220v / led monitor

[nkn]

i look for practical circuit for monitor.thanks for help.

 

[alec_t]

What do you want to monitor?

 

[nkn]

i want monitor volt 190 - 260 V . eventually curent 0 - 10 A

 

[ronsimpson]

i want monitor volt 190 - 260 V . eventually curent 0 - 10 A

Current or Voltage or both?

 

[alec_t]

Analogue or digital monitoring? Accuracy? What is the LED supposed to show?

 

[nkn]

1. voltage
2. current

 

[nkn]

digital monitoring

 

[alec_t]

A cheap DMM is the simplest solution.

 

[ronsimpson]

Search for "CR2550 current transformer". There a number of this type of current monitors.
Is this what you are looking for?

For monitoring voltage I usually use a resistor that is sized to limit current. (220V makes 10mA or 5mA for the LED) Many resistors can not take 220V so it is good to use 2 or more resistors to limit the voltage to 150 volts per resistor.

Most LEDs are not happy with reverse voltage. I usually place a small diode. 1N4148 across the LED so current in one direction does through the LED and the reverse current goes through the 1N4148.

The other option is to use a high voltage diode like a 1N4007 to block the reverse current. This uses 1/2 the power in the resistors.

Maybe you want to monitor the current and voltage with a micro. In this case isolation is very important. I use a opto-isolator in place of the LED in the above examples.