[quote author=sain link=topic=2868.msg42588#msg42588 date=1142904690]
actually its pretty easy to do - you just use an opamp as a voltage comparator - comparing the battery voltage and a reference voltage. The reference voltage should be whatever you want the battery charged up to (use a voltage divider off a constant 12v src). The output from the op amp is fed into a transistor which switches the constant current source charger on and off.

I'll find the schematic for the one I built eventually - its somewhere on a spindle of backups cds. In the meantime you can figure it out from that description, it'll make a useful exercise
[/quote]

This was from afromans forums, afro and i tested the charger and verifed that it works amazing w/o spending liek 20 bucks on a another charger,

But i need help building wat sain said, i wanted to know could i make my voltage source automatically cutoff when the battery is finished charging.

I could ask afroman and see if he could help, (becuase he has all the brains, i just got a big electronic workroom, flame free, and i test his experiments,) but afroman isnt reply to me on aim.

SO i came to yall to see what yall think about it.

 

looks like the quote didnt quile work. lol

 

[quote author=sain link=topic=2868.msg42588#msg42588 date=1142904690]
actually its pretty easy to do - you just use an opamp as a voltage comparator - comparing the battery voltage and a reference voltage. The reference voltage should be whatever you want the battery charged up to (use a voltage divider off a constant 12v src). The output from the op amp is fed into a transistor which switches the constant current source charger on and off.

I'll find the schematic for the one I built eventually - its somewhere on a spindle of backups cds. In the meantime you can figure it out from that description, it'll make a useful exercise

This was from afromans forums, afro and i tested the charger and verifed that it works amazing w/o spending liek 20 bucks on a another charger,

But i need help building wat sain said, i wanted to know could i make my voltage source automatically cutoff when the battery is finished charging.

I could ask afroman and see if he could help, (becuase he has all the brains, i just got a big electronic workroom, flame free, and i test his experiments,) but afroman isnt reply to me on aim.

SO i came to yall to see what yall think about it.

[post=15419]Quoted post[/post]​

[/quote]
I can't see what 'it' is. Can you provide a circuit?

 

This was from afromans forums, afro and i tested the charger and verifed that it works amazing w/o spending liek 20 bucks on a another charger,

But i need help building wat sain said, i wanted to know could i make my voltage source automatically cutoff when the battery is finished charging.

I could ask afroman and see if he could help, (becuase he has all the brains, i just got a big electronic workroom, flame free, and i test his experiments,) but afroman isnt reply to me on aim.

SO i came to yall to see what yall think about it.

[post=15419]Quoted post[/post]​

I can't see what 'it' is. Can you provide a circuit?

[post=15422]Quoted post[/post]​

[/quote]

below is a my batteryu charger, but i wanted to know how to make it automatically cutoff when the battery is finshed charging.

 

Originally posted by lildiesel6075@Apr 1 2006, 01:23 AM

below is a my batteryu charger, but i wanted to know how to make it automatically cutoff when the battery is finshed charging.

[post=15672]Quoted post[/post]​

You have a simple constant current charger, so the voltage across the battery will rise as it becomes charged. You could sense that voltage make a cutoff circuit.

Do you know the battery voltage when it is passing 65mA and is
1) 95% charged, and 2) fully charged?

 

Try using a flux capacitor.

Better yet, try reading up on op-amps. Click here for Op Amp tutorial

posted March 23, 2006, 02:44:20 PM by lildeezul on Afroman's Forum
yeah please try to find the schematic, on the mean time, i will look up information about a op amp, ( or whatever that thing is called), becuase i have no idea what a op amp is.