Hi there. I've got a 1000 billion$ question :
I'd like to measure voltage and current from a generator (Vmax=24V). surfing on the web i found that it would be possible using a Hall Effect sensor. How can i wire it to arduino and the generator? Could anyone explain to me its functioning??
There are several kinds of Hall current sensors or current tranducers. You either connect the wire from the generator in series with the sensors input/output pins (e.g., primary current pins or terminal pins) or put the wire through the hole in the sensor.
Many of the sensors have ICs that do the conversion from current to voltage within given range, for example between 0-5V. They have typically three pins for interfacing the uC: Vcc, GND and Vout. You connect Arduino's Vcc and GND to sensor's Vcc and GND. Sensor's Vout goes to Arduino's analog input. You may need to add resistors or/and capacitors, e.g., a capacitor between sensor's Vcc and GND. Check the datasheet for application diagrams.
Choose a sensor of which amp range matches your generator. For example, if the max. current from you generator is 6 amps DC, you may choose a unidirectional sensor that can sense currents from 0 to 10A. (or bidirectional from -10 to 10 if it is an AC generator). If you choose a sensor with too wide range (say from 0 to 100A), you loose resolution and accuracy.
For unidirectional sensors you get 0V from Vout at 0A, from bidirectional sersors you get 0-2.5V when I<0 and 2.5-5 when I>0.
The sensitivity of the sensor is given as mV/A, for example 100mV/A. (0.1V change in voltage from Vout means 1A change in current.)
Arduino has 10bit ADC which gives you values from 0 to 1023. If the sensor's sensitivity is 100mV/A and analogIn reading is 123, in the case of an unidirectional sensor the current is (5.0/(10240.1))123 = 6A. For bidirectional: (5.0/(10240.1))(123-512) = -18.99A.
Choose a sensor of which amp range matches your generator. For example, if the max. current from you generator is 6 amps DC, you may choose a unidirectional sensor that can sense currents from 0 to 10A. (or bidirectional from -10 to 10 if it is an AC generator). If you choose a sensor with too wide range (say from 0 to 100A), you loose resolution and accuracy.
It seems that "unidirection" does not always mean that the sensor is for DC only. But check the datasheet for the sensing range and what is the Vout value for I=0.
There are several kinds of Hall current sensors or current tranducers. You either connect the wire from the generator in series with the sensors input/output pins (e.g., primary current pins or terminal pins) or put the wire through the hole in the sensor.
where could i buy them?
yesterday i asked something about the generator, and the one that asked me the system told me it's a AC generator: a wind turbine
and the one that asked me the system told me it's a AC generator: a wind turbine
Sorry I did not understand that use of English. It made little sense, in fact it means that you were told it was a wind turbine, not you said it was a wind turbine.
So if you want to measure AC power why is the thread headed how to measure DC?
You can waste a lot of peoples time by not stating what you want to do.