EX ELECTRONIX EXPRESS Variable Transformer, 500 VAC Max, 0-130 Volt Output, 5 Amp: Power Converters: Amazon.com: Industrial & Scientific
Amazon.com: PWS-2420 24VAC 20VA Class II Power Supply AC Adapter UL 24V Transformer Plug with terminals : Industrial & Scientific
24V 40VA Thermostat and Doorbell Transformer, Power Supply Compatible with Nest, Ecobee, Sensi and Honeywell Thermostat, Nest Hello Doorbell and All Versions of Ring Doorbell (Style 1) - - Amazon.com
Dwyer® AC Power Transformer, APT-40-1DN, 40 VA, 120 VAC Input, Dual Hub: Amazon.com: Industrial & Scientific