seasons555copy
New Member
Hi,
I am trying to figure out a cheap way to determine if the load that I am controlling is working properly, open circuited (disconnected) or shorted (fault).
The load is one or two 24V AC solenoids each of which requires 7.2 VA.
Now my problem comes in that I have to detect the current/status of each of the solenoid groups. There will be a total of 16 groups which must be sensed seperatley because if 1 of the 16 solenoids fails, the power to only that solenoid should be stopped while allow the other 15 to operate normally. This could be expensive.
The power to my circuit is produced from the same 24VAC that is powering the solenoids.
Because of this I am not sure if a conventional OP-AMP approach would work. And if it would how could I accomplish this.
I have looked at the Allegro hall-effect based current sensors but they are about $5 each.
I would not like to spend more than a dollar or two for each channel that I need to detect.
I am also open to other solutions to produce the desired results other than a current based approach.
I should also mention that I am going to be using a pic with either 16 or 24 ADC pins on it for this purpose. Although I could get one with 32 if needs be.
I hope the above is clear enough, if not I'd be happy to clarify anything.
Thanks in advance for your advice.
I am trying to figure out a cheap way to determine if the load that I am controlling is working properly, open circuited (disconnected) or shorted (fault).
The load is one or two 24V AC solenoids each of which requires 7.2 VA.
Now my problem comes in that I have to detect the current/status of each of the solenoid groups. There will be a total of 16 groups which must be sensed seperatley because if 1 of the 16 solenoids fails, the power to only that solenoid should be stopped while allow the other 15 to operate normally. This could be expensive.
The power to my circuit is produced from the same 24VAC that is powering the solenoids.
Because of this I am not sure if a conventional OP-AMP approach would work. And if it would how could I accomplish this.
I have looked at the Allegro hall-effect based current sensors but they are about $5 each.
I would not like to spend more than a dollar or two for each channel that I need to detect.
I am also open to other solutions to produce the desired results other than a current based approach.
I should also mention that I am going to be using a pic with either 16 or 24 ADC pins on it for this purpose. Although I could get one with 32 if needs be.
I hope the above is clear enough, if not I'd be happy to clarify anything.
Thanks in advance for your advice.