DC 12V <15 amp Current Monitoring
Bob
Posts: 9
I'd like to build a circuit to monitor the current coming out of a battery charger and would like to use a basic stamp to monitor the current draw and then fire off an electronic rely to turn the 12 volt line off after the battery reaches a peak charge.
Can anyone point me in the right direction regarding monitoring this type of current using a basic stamp.· Do I need to pass one of the 12 V DC wires through some sort of coil and then monitor the coil output with the stamp?·
Any hints would be greatly appreciated!
Thanks,
Bob
Jacksonville, FL
Can anyone point me in the right direction regarding monitoring this type of current using a basic stamp.· Do I need to pass one of the 12 V DC wires through some sort of coil and then monitor the coil output with the stamp?·
Any hints would be greatly appreciated!
Thanks,
Bob
Jacksonville, FL
Comments
build or buy a current shunt ie. .1 ohm, 1 ohm etc pass current through it and read the voltage across it with a a/d converter.
If you use a .1 ohm , 12 amps will cause a voltage drop of 1.2v.
If you use a 1 ohm shunt the 12 amp flow will cause a 12 v drop across the shunt.
I have found small shunts like that at hosfelt.com in the past.
73
spence
k4kep
What kind of battery are you charging, NiMH, NiCad, Li Ion, lead acid?
·
I'm actually building an Aluminum anodizing setup - so the current draw will probably most closely resemble a lead-acid battery.· Apparently when anodizing, the setup draws current while the parts are anodizing, and once the surface is anodized, the current draw drops off rather suddenly.
Because the timing is dependent on the surface area of what is being anodized, I can't time the parts.
Click here: Allegro | Product | ACS754
Are you going to use the stamp to determine di/dt?· Great idea!· Please post your progress.
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Basic stamp Newbie
*edit*
i found the online store via froogle, but $20 seems high.
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League Bowling.... it's not a sport, it's a way of life
You might try the local appliance repair shop for some nichrome wire which is used in heating elements. It comes in various resistances and should be available in short lengths. Much higher resistance than 10 ga wire. In fact the repair shop should be able to give you some out of burned out elements.
73
spence
k4kep
Nick, The $20 is for a eval platform. The chips themselves are only $5.50 each in single unit quantities.
Jim