Hello dear SgtWookie:
when i make regulatur current before regulatur voltag(1-current 2-voltag). out put voltag change very slowly when time i turn potonsivmeter. but it is ok when replace two regulaturs. ( 1-voltag 2 -current)
what is your idea?




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What regulators are you using?

 

The output voltage may change slowly if you have no output load on the supply.

 

thanks of friends
i do work lm338
ofcourse mybe your idea is right
please send me your suggest my circuit is (1-voltag 2-current):


http://dl.electroniccar.ir/do.php?imgf=1439228034821.jpg

 

excuse i am mistake in picture to design out put. pol negative shuold conect to pol negative lm338

 

You need to pay more attention to the pinouts on the datasheets.

The diode bridge is connected to the rest of the circuit backwards.
You don't show pin numbers, but by your pictorial both 338's are connected incorrectly.
Your circuit to charge pump a negative voltage into the 7909 is incorrect.
The LM7909 is connected incorrectly.

What is the purpose of the component marked 117?

ak

 

thanks of your idea
its circuit was design of data sheet lm338 for regulatur voltage and so regulator current . forgive me i dont wrote number pin . problem me in regulator current . but its circuit correct work now. and out put 7909 consider pin in data sheet is ok. negative pin 7909 is for regulatur current by lm117 but its dont work correctly.

 

What is the purpose of the component marked 117?

What is the purpose of the 15 V zener diode at the LM7909 common pin?

ak

 

please read datasheet lm338