Reddit reviews MG Electronics Class II AC Power Supply with PTC Auto Resettable Fuse (24 VAC, 40VA)

1. Yes, it will work, and is more than enough power. Look around a bit, they make some that are contained and plug directly in to an outlet. Might help position it better.
   
   
   I use this one: https://www.amazon.com/dp/B075CTPZW6/ref=cm_sw_r_cp_apa_04LQAb367PJ8W
   
   That one's 40VA, but 1000mA is more than enough power.
   
   Worked with my Ring 2 before I switched to Nest.
   
   
2. Don't know if you need a resistor. I had a chime installed.

I have the GoControl - it works just fine and is very unobtrusive. I use an external 24V power supply with it as I have a 40-year old furnace with a 2-wire control and no 'C' connection. We can say "OK Google set the thermostat to 70" or "OK Google make it warmer", and use the SmartThings app to adjust the heat when we're away from home. (Note the comment I added above about smart outlets.)

Someone on this forum recommended [this] (https://www.amazon.com/gp/product/B075CTPZW6/ref=od_aui_detailpages00?ie=UTF8&psc=1) for adding a C wire. It works great! Follow this [diagram] (https://www.doityourself.com/forum/attachments/thermostatic-controls/48111d1426649484-wireless-thermostat-replace-wired-honeywell-th8320r-external-transformer-n-boiler.jpg)

im using this to power the ecobee

the way this works is there are two posts each sending 12v. One leg (yellow) is connected to the rC and the other leg (blue) is connected to the C for a total of 24v.

I want to know if i can just splice the two 12v legs into one and get 24v for the C.

the rC getting 12v seems to be tricking the furnace into thinking it needs to pump heat.

I have a 2 zone, 2 taco system that ecobee tells me to use a fast-stat along with the transformer to "add a common" but I dont need to add a common...i have a free wire already, so im trying to utilize it (if possible)