Powering Doorbell with 15 VDC from existing Doorbell

Using this device makes it possible to quickly run from 15 vdc power.

DROK 090187 DC-DC Volt Buck Converter Step-down Regulator 8-50V 12V/24V/36V to 5V 3A Power Supply Module Volt Inverter Board with Micro USB Adapter Connector Waterproof which be found on Amazon.

So this is for when you don’t have the native 16V-24VAC from the old doorbell, and don’t have a way to get 5V to it either? Where do you get 15VDC?

My intercom system had 15vdc riding on the door switch. So I just used this device to reduce it down to 5vdc. I like simple.

Did the doorbell not run on the 15vdc?

The doorbell will run on 16V-24VAC if you use the screw contacts, and 5VDC if you use the USB mini that is under the gray pad on the back (there for factory test, but can be used in the field if you otherwise protect the doorbell from water).

Using a 15v DC to DC converter to 5 volts DC works just fine.

I guess my question was, does the doorbell (for a fact) not run on 15vdc, since most low voltage AC devices simply rectify the AC and therefore will work on DC?

I used the USB port and a DC to DC converter to step down the voltage FOR A FACT IT WORKS

Yes, I understand.
I was wondering if it was actually necessary since most small electronic devices being powered from AC will also accept DC.

Did you test it on DC? Did it fail to work?

That is a good way to burn out the doorbell, doing such a test.

Interesting premise, but wonder how you get to that conclusion.
If the first component in is a transformer, I could see the concern, however if the first component is a rectifier (as is typical) I would not see the concern.

You should buy a doorbell and give it a try. Report back.

It is on my list.
Just trying to learn what is known,

I wonder how unusual it is to have 15VDC there. There may not be much experience.

A normal doorbell has 16V-24VAC.

Yep, typical, is a very unregulated 18VAC from a “Doorbell/Thermostat” transformer, less a whole lot of voltage drop from the wiring.
It all depends how they designed the power input, but given the amount of induced noise and spikes long wires can get, I would rather not bypass any protection built into the designed power input circuit.
My building will be primarily 12V DC powered, and I am trying to avoid power wasting voltage converters where I can.

If (as I suspect) it stars with a bridge rectifier followed by a filter and voltage regulator, it is likely to run well all the way down to about 8 VDC.

Right now it is all guessing, till I get one. (Or someone else has done the work)

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If your doorbell is part of a intercom system, then it is common to have 15 volts DC.

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