I am planning to install a Ring branded video doorbell at a home I am visiting for a few days. We are struggling to find a doorbell transformer on short notice, but did find a halogen light transformer.

It's not a perfect match of the requirement as the intended light would pull much more power than the doorbell, I'd like to know if it's likely I damage the transformer and then in turn Ring doorbell if I try this transformer or use it for a weeks until we have a better replacement.

I also read something about halogen transformers not being suitable for LED lights due to randome wavelengths in the output frequency, and I wonder if the same is an issue for the Ring doorbell.


  • 8-24 VAC, 10-40VA, 50/60 Hz

Specification of the transformer:

  • 11.5 VAC, 4A (it would transform from 230v, 50Hz)

The transformer lists 12v 50 watt as the intended light.

  • let's see ... the doorbell requires between 8 Vac and 24 Vac ... the transformer supplies 11.5 Vac .... what do you think?
    – jsotola
    Dec 23, 2021 at 9:34
  • I am not concerned about the voltage. Instead the doorbell would pull much less power than the intended light bulb and I am not sure if this is good for the transformer and then in turn the doorbell. I'll edit my question. Thanks for your constructive comment. Dec 23, 2021 at 9:36
  • 1
    We've seen discussion of people trying to make Rings work and they find the higher voltage the better. Contact an HVAC supply house for a transformer, they come in many form-factors. Any common 24V thermostat transformer should suffice, it doesn't need to be branded as "doorbell transformer". Dec 23, 2021 at 10:23

2 Answers 2


General rule of thumb for power supplies…

  1. Voltage must match - I would normally say exactly but your input requirement seems to have a huge tolerance.
    11.5v into 8-24 is just fine.

  2. Amperage must equal or exceed requirement. 1VA == 1W. [Amps x Volts == Watts]
    In simplistic terms, amps are 'pulled' by the device not 'pushed' by the power supply. So if a PSU can supply 5A but the device only needs 4, it will only 'pull' 4. This will not hurt the supply at all - otherwise can you imagine all the phone chargers etc pulling 20W from sockets that can supply 13A at 240V??
    Again, as your device tolerance is between 10 & 40W & you can supply 50 [11.5V x 4A = 46W not their claimed 50… but close enough], there is no issue.

  • Thanks for your answer and I accepted this as it nicely breaks down the answer. I also appreciated Jasen's answer. As to anyone who is trying to do the same: the Ring was working fine while testing and being connected on the halogen transformer. However when we installed it on the door and turned it on, the ring started smoking and stopped working. Since it was working while testing we suspect we made some error along the way and had a faulty connection. Having said that, I don't dare to recommend using a halogen transformer to any Ring owner either. Jan 4, 2022 at 21:22

you've got a 50VA transformer there and the ring wants 10-40VA

Using less than the rated power can result in a slightly higher voltage coming out of the transformer, but I wouldn't expect more than 15V from a 12V transformer, the ring can handle more than that, so it should be fine.

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