Sir / Mam,
please help me to check if the attached diagram is correct even i can use for 24 hours.
i am new in electronics and i want to learn it more.
thank you.

 

Hello,

Is this a school project?
What should be the capabilities of the powersupply?

Bertus

 

sir, this is for personal use only for my house. i need 1.2 to 24 volts.
this is also studying more about electronics.

 

Hello,

R2 and R3 will not allow you to go down to 1.2 Volts.
R1 will limit the output current dramaticaly.

Have a look at the formula below the schematic to calculate the output voltage:



Bertus

 

Personally, I would eliminate R1 and C4.

There is some value to R1 if you plan to need 'high' current at low output voltage. In that scenario without R1 present, you would be dropping a lot of voltage across the regulator and its heat dissipation will limit the current you can draw. The resistor can take some of the heat load instead. But R1 at 22Ω will drop 11V at just 0.5A, severely limiting your output range.

I used to use C4 but I now believe it's not useful. It won't hurt to have it, but I don't think it adds value.

 

An LM317/117 needs both because it is an adjustable regulator. The supply current will be limited to less than 1 amp because of that regulator's limitations. But for hobby and learning one really does not need a continuously variable supply, just using a string of forward biased diodes to vary the output in 0.7 volt steps would be adequate and then a regular power tab could be used. Lower than 5 volts would not be available without additional circuitry but are those really needed ?
And for more current just add a PNP power transistor wrapped around the regulator and as much current as is needed would be available.

 

Anyone can share their diagram for 1.5 to 24 volts so i can make it. Thanks
If i will continue my diagram, my plan is to remove the R1, how about R2 and R3, what resistance right to put?

 

See my thread in the projects forum.