cravenhaven
Senior Member
Having just destroyed my LCD display because of a meltdown in my external current sensor, I am looking for ways to fully isolate the sensor from the rest of the circuit. The problem was caused by the sensor sending 12v onto the 5v feed line which is of course the same 5v that feeds the PICAXE and LCD. The problem is that the output of the sensor is an analogue voltage that is proportional to the current sensed and voltage applied.
The current sensor is the ACS714 from Allegro: http://www.allegromicro.com/Products/Current-Sensor-ICs/Zero-To-Fifty-Amp-Integrated-Conductor-Sensor-ICs/ACS714.aspx
I managed to damage the sensor by attempting to incorrectly attach a second battery to my main battery, and the resultant current spike melted the sensor and hey presto.
My plan so far is to isolate the sensor input to the PICAXE by using a voltage follower opamp, but how do I provide 5v to the sensor that is exactly the same level as that provided to the PICAXE and LCD without having it directly connected?.
The current sensor is the ACS714 from Allegro: http://www.allegromicro.com/Products/Current-Sensor-ICs/Zero-To-Fifty-Amp-Integrated-Conductor-Sensor-ICs/ACS714.aspx
I managed to damage the sensor by attempting to incorrectly attach a second battery to my main battery, and the resultant current spike melted the sensor and hey presto.
My plan so far is to isolate the sensor input to the PICAXE by using a voltage follower opamp, but how do I provide 5v to the sensor that is exactly the same level as that provided to the PICAXE and LCD without having it directly connected?.