Voltage & Current mesiurement with 16F877a

[Foldesa]

Hi !

Do you have any idea of how to messiure DC voltage (20volts-5volt) and current (~15 volt 0-25 amper) with pic 16F877a, even with external circuit(s).

Thanx

András

 

[cyr]

Well, the 877 has A/D converters so it's not that difficult. All you have to do is convert whatever you want to measure to a suitable voltage range (0-5V usually).

To measure 0-20V simply divide the voltage using two resistors.
To measure current, use a shunt resistor (something like 0.01ohm, perhaps even less), and amplify the voltage over this resistor using an opamp.

 

[manu]

To mesure voltage, use 877's ADC with a divider using 2 resistors ( Uout must be Uin/4 )

To mesure current, use a low impedance shunt and comparator ( TLV3701 is very fine and tou must obtain this one for free ), you must amplify the signal, or use different voltage references, since U = R*I

Regards,

Manu

 

[Foldesa]

Hi

I will try them.

Thanx.

 

[eanupam]

Can I measure the line voltage by 16F877A.

I want to measure 230 VAC 50HZ.

please suggest me a circuit.
thanks
Anupam

 

[microcozmoz]

**broken link removed**

Look at this datasheet it may be useful for u

AN521-İnterfacing AC power Lines

 

[metal]

Hi

I found this while surfing the net:

https://www.coolcircuit.com/project/meter/index.html

Hope its useful.