In the previous circuit from post #14 the attatch diagram.
If i am connecting resistor 12Ω to 0.24Ω (Current Regulating 100mA to 5A) in different steps. 10 or 12 resistor diffrent value connect through a rotary switch to vary the output current than this cct suitable for regulating current or not.

thanks a lot SgtWookie

 

If the LM338 ADJ pin is connected to the junction of R1 and R2, the output will be limited to 5 Amperes.
If the LM338 ADJ pin is connected to the junction of R2 and Vin of the LM137/LM337, the output will be limited to 0 Amperes.

If you have a 12-position switch, you could then divide the 150 Ohms by 10 to get 11 total selections, each step 0.5 Amperes; each resistor being 15 Ohms.

Steps:
5A
4.5A
4A
... (3.5A to 1.5A)
1A
0.5A
0A

 

circuit attatch
if i am this cct use
If i am connecting resistor 12Ω to 0.24Ω (Current Regulating 100mA to 5A) in different steps. 10 or 12 resistor diffrent value connect through a rotary switch to vary the output current than this cct suitable for regulating current or not.

thanks a lot SgtWookie

 

No, that is wrong.

 

Do it like this:

 

In the previous circuit from post #26

No, that is wrong.

How that is wrong Please help me and explain it
Thanks



post #27
in This cct how provide -ve supply please help with diagram

thanks a lot SgtWookie

 

post #27
if a am using this cct to provide 100mA then Resistance Value
and if a am using this cct to provide 5A then Resistance Value
thanks a lot

 

In the previous circuit from post #26

How that is wrong Please help me and explain it

On paper, it works OK.
The problem is that all of the output current from the LM338 will pass through the switch and resistors. You would need a very heavy-duty rotary switch, and all of the resistors would need to be large power resistors. This would make your current limiter very expensive to build and troublesome.

In the circuit with the single 0.24 Ohm resistor, it is the only 20W power resistor that you will need. The other 15 Ohm resistors can be very low wattage, and the rotary switch only has about 10-11mA flowing through it, instead of up to 5A current.

post #27
in This cct how provide -ve supply please help with diagram

In your circuit, you have a transformer with rectifier diodes supplying a filter. You will need larger capacitors in the filter.

In the version that requires a negative supply, you will need another small transformer, that outputs around 6VAC, or if center-tapped, each side 6v. A 0.1VA rating would be more than enough power. You will also need a small rectifier bridge, and a small capacitor to keep the -5v more or less stable. It is not important for the negative voltage to be regulated.

 

In the version that requires a negative supply, you will need another small transformer, that outputs around 6VAC, or if center-tapped, each side 6v. A 0.1VA rating would be more than enough power. You will also need a small rectifier bridge, and a small capacitor to keep the -5v more or less stable. It is not important for the negative voltage to be regulated.

In this cct the +ve lead connect to ground and gnd lead connect to -Ve pin

All the resistor 1/4W or 1/2W

if a am using this cct to take 100mA then Resistance Value
and if a am using this cct to take 4A then Resistance Value


Very Very thanks a lot SgtWookie

 

I cannot seem to make you understand that the way you want to build the circuit will not work.

I am spending too much time trying to explain this project to you.

 

Sgt.
I think OP doesn't understand ohm's law very well.
And also OP doesn't have a clue on how current limiting and feed back of a typical cct works.
It is why OP is having a hard time how the cct works, he thinks paper work and practical application is same, and the environmental variables are not taken into account.

If so this is a next to impossible situation.

 

Thanks a lot SgtWookie
Please do not angry
you are a great man




my question apply this cct

please do not angry

 

my english is week

 

He is not angry buddy.
It's sometimes really difficult when one have to deal with so many people at once.

 

He is not angry buddy.
It's sometimes really difficult when one have to deal with so many people at once.

Thanks a lot SgtWookie
Thanks a lot Rifoo

 

Thanks a lot Rifoo

SIGH!!! Who's next?

 

If i am trying to this cct on bread board for check resitance value whos VARY THE OUTPUT current from 100mA,200mA,400mA,800mA,1600mA,3200mA than this resistance change path connect to parallal (ON requirement) and change out put current digitally.

If i am connect a Ammeter across I-Out serially and output lead short to ground than ok or not any component destroy or not

thanks

 

Never short out a voltage source with an ammeter, tht's the dumbest thing you can do

 

Attach Image

Never short out a voltage source with an ammeter, tht's the dumbest thing you can do

Because any power supply the current limit when the output lead short and rotate output current variable for change output current

this cct is ok or not
OR
current regulator before voltage regulator the output lead short voltage regulator

if not

how current limit and how watch max current on ammeter

Brother SgtWookie please dont angry
you are my friend
you are a nice man
you are a good man
please dont angry
please forgive
thanks

thanks

 

thanks a lot Rifoo