9volt Battery Charger questions

Thread Starter

samsam_91

Joined Dec 1, 2012
10
Hello Everyone >>

I need to make a charger for 9 volt battery , have a circuit but want some help about resistor of regulator ..

<snip>

my questions on :
1) R1 ,R2 ,R3 values to make a regulator work and also with transistor to make a LED On if it still charging and Off if it fully charging if the battery capacity is 175 NiMH

2) If I'll use lm317 what changes in the circuit ?

and finally please write the equations you have used to find Resistors values to apply it if I have changes ..

thanks :)
 
Last edited by a moderator:

wayneh

Joined Sep 9, 2010
16,390
I'd move D2 to protect the regulator against the output (the battery voltage) being higher than the input (eg. if the AC is unplugged).

I believe your rectifier DC connections are backwards also. Still drinking my coffee, so I might be confused.

I'm sure you'll be getting answers to your other questions.
 

Dodgydave

Joined Jun 22, 2012
9,157
Either you have forgot the transformer for your power supply, if not i believe this is a transformer-less psu and is therefore forbidden !!!!
 

wayneh

Joined Sep 9, 2010
16,390
Dodgydave is a bit more awake and has correctly noticed a very critical flaw! That 7809 would pop like a balloon if it saw 300V.
 

Georacer

Joined Nov 25, 2009
5,182
As Dodgydave says, non-isolated circuits connected to the mains are not allowed in AAC. Please update your schematic with an isolation transformer and a fuse, even if its ratio is 1:1.

Thank you for your understanding,
Georacer
 

Thread Starter

samsam_91

Joined Dec 1, 2012
10
The bridge rectifier terminals 1/4 are the wrong way, also the voltage source is 220v ac NO Transformer!!!...
Unfortunately I dont have a good sim to make a circuit it's not contain a transformer and also the bridge not have "AC" and "positive or negative" pins .. but anyway I will do it true on board dont worry about this :)
 
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