How do I build the current regulator circuit referred to on the LM337 datasheet?
Use them exactly as you used the 317, -ve supply input to Vin, load between ground and ADJ, resistor between ADJ and VOUT. As shown in the schematic below:







simulate this circuit &ndash; Schematic created using CircuitLab

They are shown the way they are shown in the data sheet because current flows from ground, out of Vin and into your -ve power supply pin - remember conventionally we say that current flows from +ve to -ve