Trane Parts TRR1898 208/240-24V 50VA Transformer: Amazon.com: Tools & Home Improvement
24VAC 50VA Wall Transformer with PTC Fuse Compatible with All Versions of Doorbell,Nest, Ecobee, Sensi and Honeywell Thermostat,Water Solftener,Screw Terminal Output - - Amazon.com
Honeywell AT150F1022 - Transformer, Plate or Panel Mounted 120/208/240 Vac, 24V AC @ 50 VA - - Amazon.com
Square D 9070T50D13 Control Transformer, 50Va, 12/24Vac - Electronic Power Transformers - Amazon.com