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The Projects Forum Working on an electronics project and would like some suggestions, help or critiques? If you would like to comment or assist others with their projects, this is the place to do it.

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Old 08-04-2009, 10:57 PM
electrocub electrocub is offline
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Default LED current indicator

I am building the circuit below to charge 12 volt SLA batteries. I would like an indication of what the circuit is doing. I have a 12 volt comparitor circuit I can hook to the battery to see what the voltage reading is. What I am looking for is a circuit containing a led that would be in series with the battery so I can tell when the current goes from high to low. Would a mosfet work? Could I use a logic chip? What are some of your thoughts? Thanks.


Flashing battery monitor Source:

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Old 08-04-2009, 11:34 PM
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Ron H Ron H is offline
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You didn't include a link to the project.
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Old 08-05-2009, 01:21 AM
electrocub electrocub is offline
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Default Sorry, try this link.
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Old 08-05-2009, 02:13 AM
k7elp60 k7elp60 is offline
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Default LM317 battery charger

Here is a link to a battery charger I build using the LM317T.
I use a dual op amp as a comparator to monitor the charge current and turn on an LED when the current drops to a set level.
It may give you some ideas.
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Old 08-05-2009, 02:44 AM
electrocub electrocub is offline
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Default Thanks

Thank you. In my search for a battery charger, I saw your circuit, but missed the led. If I wanted to dress it up a bit, instead of the resistor and led, I could turn on a 555 with a flasher or do about anything I wanted to with the output couldn't I? Put a flip flop so when it was high, one led would light, then low, another? Thanks again. I am very much an amateur, but enjoy it so much.

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