there has to be an easy explanation...

[inkedallusion]

I am trying to use an ecg 957 voltage regulator in place of a LM317T radio shack voltage regulator. They both have about the same specs, but the ECG 957 is -1.2V to -37V instead of poitive voltages. I am building a basic power supply, and I am thinking I will have to change the connections around from the bridge rectifier, and change the polarities of the capacitors in paralell between the positive and negative sides of the rectifier. as well as the led direction. I know this is hard to answer without a schematic, but can anybody help me? I can email the schematic to anybody if needed.

 

[kinjalgp]

Just reveres the output terminals. i.e The common terminal will be your positive terminal and the output of IC will be your common terminal. Now in this case instead of varying the +Ve terminal with respect to common, you are doing the reverse. But no harm in doing that.

 

[absolution]

:evil: maybe using the inverting input of an op amp for the sole use as an inverting buffer might work to give your desired positive output, not too sure never really used op amps like that but its a suggestion :twisted:

 

[kinjalgp]

:evil: maybe using the inverting input of an op amp for the sole use as an inverting buffer might work to give your desired positive output, not too sure never really used op amps like that but its a suggestion :twisted:

I this case what do you'll need a power op-amp which can source 1A of current. And from where will you power the op-amp? Require another supply for that!!!! :roll:

Inverting op-amp configuration are used only for small signal inversion and not for power signal inversion.

 

[Russlk]

Here is how you use it:

 

[kinjalgp]

Yes, Russlk. Thats exactly what I meant in my first post.