LM337 circuit

[adrian1232]

Hi all,
I have built a negative supply circuit using an LM337. Now my problem is, can i supply this circuit with a wall variable DC Power Supply?? if yes, how shell i connect the terminals?

Attached please find the circuit and a photo of a similar supply which i am going to use.

thanks in advance

 

[(*steve*)]

You should be fine as long as the output voltage doesn't exceed the 337's max input voltage and it is reasonably filtered (depending on what value you choose for C2).

Remember there's no magic about this power supply. It will be pretty much indistinguishable from a normal +ve power supply (unless you have a +ve PSU to connect it to)

 

[adrian1232]

Thanks for the reply Steve...
But to have a negative supply at the output, i have to connect the positive terminal of the wall supply with the -Vin ?? because i have tried this on Proteus (ISIS) and the output voltage was positive not negative...

 

[(*steve*)]

No, in this case +ve is ground, and -ve is -ve.

 

[adrian1232]

so basically i cannot supply it with a wall supply?? i have to use a transformer ??

 

[duke37]

The wall supply has a transformer in it so you are using one already.
I note from the picture that the supply has several plugs that can be connected either way round. Make sure that you get the polarity right before connecting to your circuit.

The wall supply will be isolated from ground so can be used as a positive or negative supply, just depending on where you connect (or define) ground.