In some cases Hatch halogen transformers can drive LED MR16 loads but Hatch does not warrant them for these applications.
The reason for this is that the halogen transformers were designed long before LED MR16 designs emerged and they use a completely different topology/control circuit. The halogen transformers do not ‘self-oscillate’ – they depend on the impedance of the lamp itself to create a resonant circuit. LED MR16 lamps have their own mini-driver board in them so they do not present an appropriate impedance to the transformer. The LED version of the transformer overcomes this problem by using a special control integrated circuit that has a fixed oscillating frequency. Although this topology can be used to drive a halogen lamp, the reverse is not true. An RS-LED transformer should always be used if the load is intended to be a self-ballasted LED MR16 load.