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Does Your Ring Doorbell Need A Resistor/Diode?

If you noticed that Dave down the road just got a fancy new smart doorbell, you might be tempted to go out and buy one too. (Side note: why does Dave always seem to have all the latest gadgets and cars? That guy sucks…)

So you see the latest Ring Doorbell on sale, and purchase it. Great. Then you open the box, and some electrical thingies fall out of it:

The included jumper bypass cable and kit in a Ring Doorbell box
The included jumper bypass cable and kit in a Ring Doorbell box

As you flick through the manual, you realize that… the instructions are confusing! Thankfully after some Googling and YouTube watching, you broadly piece together what you need to do. But one question remains: why do some of the Ring instructions mention a resistor (or diode)? Are they needed?

And if they are needed… why aren’t these included in the box? Fear not, I’ve been through this frustration more than once. The short answer here is:

Some Ring doorbells do require a diode, or a resistor – especially if you are wiring them up to an existing doorbell chime unit. However some newer Ring Doorbells have built-in wiring that negates the need for a diode/resistor.

Disclaimer: Before diving into this topic in more detail, it’s worth pointing out that you should always hire a qualified electrical contractor in if you aren’t sure what electrical work needs carrying out. Electricity can kill – better safe than sorry!

Battery and Hardwired Ring Doorbells

A Ring Doorbell Pro 2 with a Blue Print faceplate
A Ring Doorbell Pro 2 with a Blue Print faceplate

Ring are one of the biggest names in the smart home world, and this is in large part due to their range of smart doorbells. These allow you to remotely speak to visitors and delivery drivers (via your smartphone), from anywhere in the world.

In addition to their convenience (no more missed parcels – yay!), they are also useful for crime prevention. After all, getting a 1-2 minute video clip of anyone who is scoping out your property can deter many would-be burglars.

Ring’s doorbells are available in two broad groups:

  1. Ring’s battery doorbells. These contain a battery, allowing for easy installation. There’s no wires, and no fuss. Just mount it to your door, doorframe or wall, and it just works. Of course, the battery does drain down – meaning that you have to recharge it every so often.
  2. Ring’s hardwired doorbells. These do not contain a battery – meaning that you have to wire them up to your home’s electrical wiring (unless you have the PoE Ring Doorbell Elite, that is). While this makes the install process more complicated, these hardwired doorbells have better motion-detection because they don’t need to worry about energy conservation as much.
A Ring Doorbell Pro suspended in mid-air by the wired-up supply cables.
A Ring Doorbell Pro suspended in mid-air by the wired-up supply cables.

Because it can get a bit annoying to remove and recharge your battery-powered Ring Doorbells, Ring allows you to also wire these up to your old doorbell’s wiring. This gives the battery a constant trickle charge, meaning that you don’t need to manually recharge them as much (or at all).

Many of Ring’s doorbells also allow you to ring your old doorbell’s chime, assuming that it’s compatible:

A labelled Deta C3501 doorbell transformer/chime wall-mounted unit, showing the incoming 230V cable on the bottom left and the outgoing CAT5 cable on the bottom right.
A Deta C3501 doorbell chime unit.

Note: This distinction between hardwired and battery Ring Doorbells, and also whether you are planning on ringing your old doorbell’s chime, is quite important. That’s because your decision may (or may not) require a resistor/diode in the circuit.

What Are Resistors And Diodes?

Before going into whether you need a resistor or a diode, let’s quickly recap on what these are:

  • Resistor – A resistor regulates (i.e. limits) the potential flow of electricity to a device – in this case the Ring Doorbell. Without a resistor, your Ring Doorbell could potentially receive too much electrical current – which might result in it being damaged (or even bricked). You will probably need a resistor if you are wiring your Ring Doorbell directly to a transformer.
  • Diode – A diode is a bit like a one-way switch: it is an electrical component that essentially ‘directs’ electrical current in a particular direction. If you have a digital chime unit (bell), you probably will require a diode in your circuit.

I wanted to highlight those differences because both resistors and diodes seem similar (indeed, a lot of this article says things like “resistors/diodes” for simplicity), but they are different.

Thankfully though, you almost certainly won’t need both a resistor and a diode when wiring up your Ring Doorbell. Sometimes you can skip both, and other times you will need one or the other – but not both.

When Your Ring Doorbell Requires A Diode

Various electrical components including many diodes
Various electrical components including many diodes

If you have an older Ring Doorbell and also a digital doorbell chime, you almost certainly will need a diode. This is because without a diode, the electrical current may flow from the digital chime unit (towards your Ring Doorbell) in such a way that your Ring Doorbell gets damaged. A diode will prevent this from happening.

Having said that, later versions of the Ring Doorbell have a diode built-in, meaning that you don’t need one.

Yes, this is a bit confusing. The original Ring Doorbell 1 and 2 do require a diode, and the Ring Doorbell Pro 1 might also require one – if they’re hooked up to a digital doorbell chime. But that’s about it.

The Ring Doorbell 3 and 4, and the later hardwired doorbells (such as the Pro 2) do not require a diode. The confusingly named Ring Doorbell 1 (2020 Model) also does not require a diode. This is all confirmed on Ring’s help pages:

Note how both articles say that a diode is required, unless you have the “Ring Video Doorbell 2020 Model” (also called the Ring Doorbell 2nd gen):

If there is no diode in the box, you most likely have the Ring Video Doorbell (2nd Generation), which has a built in diode.

Ring help pages

To Summarize: Unless you’re using a digital doorbell chime and you have an older Ring Doorbell, you can skip the diode.

Unfortunately the situation is more complicated when it comes to resistors!

Which Ring Doorbells Need A Resistor

A resistor is often needed in your circuit if you are wiring directly from a transformer to your Ring Doorbell. This transformer might be one of the official Ring ones such as the following first generation DIN rail transformer:

The overall Wylex enclosure with the Ring transformer inside, and all the cabling shown.
A Ring DIN rail transformer (first gen).

Alternatively, you might have a third party transformer – basically, anything that takes a mains voltage supply (120-240V) and converts it to the required 16-24V AC for your Ring Doorbell.

In both of these cases, you will need a resistor. However if you have the latest (second generation) Ring transformer, you will NOT need a resistor:

A second generation Ring DIN Rail transformer included with the Ring Doorbell Pro 2
A second generation Ring DIN Rail transformer (included with the Ring Doorbell Pro 2)

That’s because the second generation transformer includes a built-in resistor, meaning that you don’t need a separate resistor in your circuit.

The above information applies to the Ring Doorbell Wired, Pro 1 and Pro 2 – i.e. the hardwired Ring doorbell line-up. But what about the battery-powered Ring Doorbells? Well, you still need to remember the advice above (i.e. that you can skip the resistor if you have a 2nd gen transformer).

But, the Ring Doorbell 3, 3 Plus and 4 ranges have built-in wiring that mean you can skip a resistor even if you use the first-gen Ring transformer or a third-party transformer.

Hopefully that’s fairly clear, but if not – here’s a definitive table showing whether a resistor is required or not:

Ring DoorbellRing Transformer (1st Gen)Ring Transformer (2nd Gen)Third Party Transformer
1YesNoYes
1 (2020 Model)YesNoYes
2YesNoYes
3NoNoNo
3 PlusNoNoNo
4NoNoNo
WiredYesNoYes
ProYesNoYes
Pro 2YesNoYes
Whether a resistor is required or not, for each Ring Doorbell.

So that brings us onto our next question: what resistor should you use?

PSA: The Pro Power Kit IS A Resistor

Ring sell a “wirewound resistor” which should work just fine as a resistor, but did you know that the Ring Pro Power Kit is also a resistor? This is the small white device that is pictured below (sorry for the blurriness):

The Ring Pro Power Kit V2
The Ring Pro Power Kit V2

This was included in the box of my Ring Doorbell Pro 1, and it’s sometimes included in other Ring Doorbell models. But since the second generation Ring DIN rail transformer has a built-in resistor, the Pro Power Kit is slowly being deprecated by Ring.

Either way, if you are able to get your hands on a Pro Power Kit, this will work really well. I have my Ring Doorbell Pro 1 and Pro 2 wired up as explained below:

A diagram showing the final wiring plan for my Ring Doorbell Pro, going from the consumer unit to the Ring Pro (with the Ring transformer in the middle, and the bypass/power kit included).
The final wiring plan for the Pro, including the ‘Pro Power Kit V2’ (or ‘Bypass Kit’) in the output cabling.

The ‘resistor’ here (from output 1, to the Ring Doorbell Pro) protects my Ring Doorbell from any electrical surges which could otherwise brick my device.

This is particularly important when you have a Ring Doorbell that supports ringing a mechanical or digital chime, because the app specifically asks you whether to ring a chime or not:

The Ring app asking for the type of chime to play a sound with: the options are none, mechanical and digital
The Ring app asking for the type of chime to play a sound with: the options are none, mechanical and digital

I don’t have any doorbell chime connected. Therefore if I selected “mechanical” or “digital” and then pressed my Ring Doorbell, a power surge would occur that could damage my Ring device. But thanks to the resistor (i.e. the Pro Power Kit), I am protected from this.

There are other reasons why a resistor is required in certain wiring set-ups, of course, but that’s one obvious example. Hopefully this article has made a confusing situation slightly less confusing for you!

About Tristan Perry

Tristan Perry is a software developer who is passionate about tech gadgets, DIY and housing. He has therefore loved seeing smart homes hit the mainstream. Tristan also has an academic background (in Math & Computer Science), and so he enjoys digging into the technical ways that smart home devices work.

Tristan owns close to a dozen Amazon Echo devices, way too many Philips Hue bulbs and lightstrips, a boat-load of Ring Cameras and Doorbells... and a bunch of other smart home devices too (from Reolink, Google Nest, GLEDOPTO and others).

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