Smart Plugs & Devices With Electric Or Physical Switches

Smart plugs are great (or so the marketing says…) – they can easily be used to turn household devices and appliances on/off via your voice, a phone app, automated schedules, and more.

Awesome. Unless, of course, you want to control a device which has an electric or mechanical switch – like the red switch below:

My Dolce Gusto coffee machine with an electric physical switch
My Dolce Gusto coffee machine with an electric switch

In this case, in order to turn my coffee machine on, I actually need to press the switch on the top (which is currently showing up red).

As a result, my coffee machine could never be used alongside a smart plug because it wouldn’t do anything after the smart plug turns it on. Unfortunately quite a few other devices are similar, including TVs, computers and more. So what can be done about this?

Some devices – including TVs – allow you turn off the ‘soft standby’ power option, allowing them to be controlled with smart plugs. Other devices require different workarounds, or sometimes they simply can’t be used with a smart plug.

Recapping how smart plugs work

Philips Hue smart plug unboxed - but not yet plugged in
Philips Hue smart plug unboxed – but not yet plugged in

Smart plugs are pretty useful devices – they plug into a wall outlet, and then you plug an appliance into the smart plug. Just like smart lighting, you should keep the power (on the wall) on – and then use the smart plug’s functionality to control the on/off state of the plugged-in appliance.

This can be especially useful for making sure that high energy devices are definitely turned off when you’re away from the home, and also turning on slow cookers a few hours before you’re travelling home from work.

Whilst this all sounds great, there is a fundamental problem – one which I touched on earlier: electric (aka physical/mechanical) switches. These often control a device’s on/off state independently of any smart plug (or wall switch)…

The problem with electric switches and smart plugs

The majority of new devices and appliances nowadays seem to have electric switches (also called physical or mechanical switches). These control the device’s power state (i.e. whether it’s on and off) irrespective of whether power is flowing to it from the wall outlet. These exist in laptops and PCs:

Electrical - physical - switch on a laptop
Electric switches on a laptop
Electrical - physical - switch on a desktop PC case
Electrical switch on a desktop PC case

Along with bigger ‘white good’ appliances such as dishwashers and washing machines:

Electrical - physical - switch on two kitchen appliances
Switches on two kitchen appliances

And also on LED lights, such as the ring light I use when filming YouTube videos:

Electrical - physical - switch for a ring LED light
The switch for a ring LED light

There are two subtle differences between some of these switches:

  • Physical/mechanical switch: these flip the power state between two states (on and off) when pressed, with no ‘memory’ of what the previous state was. In this way, they are purely dumb, mechanical switches that control power flow – just like wall switches for lights.

    A physical connection inside the switch controls whether power flows to the end device or not, and these types of switches are commonly used on side/floor lamps.
  • Electric switches: this is a button that can alter the state of a device, which is often used for “on” and off” on a device – but on laptops they often control whether a device goes to sleep/hibernate too.

    These are usually implemented with microcontrollers that that detect a button push, and ‘pass’ this onto firmware that decides what should be done – i.e. whether to turn on/off, or go into a sleep/hibernate state.

Whilst it can be hard to tell which is which, it’s key to understand this distinction because electric switches often render smart plugs useless, because even if the smart plug is told “turn the device ON”, the device’s switch may still be in the “OFF” state – meaning the device won’t come on anyway!

This is often why smart plugs suggest that if a device has a physical on/off switch, you keep this ON so that the smart plug can then control it more normally. But what should you do about other devices, especially ones with standby or ‘soft on/off’ states? And can you do anything to ‘fix’ devices with electric switches? I cover these question in the next few sections.

How to use a smart plug with a TV or projector

As part of an ongoing push to save wasted electricity, an increasing number of power-hungry electrical goods such as TVs and projectors contain standby modes.

These can reduce energy consumption from 85W down to 10W on a decade-old LG TV, with the potential to get this below 1W using proper standby technology.

Whilst this is great, it also makes using smart plugs with TVs and overhead projectors difficult because by default they don’t fully turn on when power is supplied to them – they merely move into a standby state. You then have to get the remote and press ON before it actually comes on.

So how can you ‘fix’ this, so that they can be used with smart plugs? Well, this might be possible – but it very much depends on your TV or projector.

Some devices allow you to turn off standby modes under the power settings menu, or enable a mode such as “direct power on” which Epson projectors offer:

Direct Power On: lets you turn on the projector without pressing the power button

Epson Projector manual.

When this is enabled, you can literally control your TV or projector with a smart plug without any issue – when the smart plug says ON, the device comes on. Awesome.

However many consumer level TVs don’t offer this option, meaning that smart plugs often can’t be used here. But there is another option which I cover in the next section.

Another way of smartly controlling your TV (without a smart plug)

Whilst controlling your TV with a smart plug may not be possible (if you can’t turn off standby, that is), you can actually smartly control it in a much better way – using something called an IR blaster.

An IR blaster is a little device that connects to your TV and accepts infrared ‘requests’, such as those sent from a TV remote.

However it’s accepts ‘requests’ from more than just a remote – you can pair this with a compatible smart hub and connect a mini-IR blaster to this as well:

Diagram showing how IR blasters work with smart or harmony hubs
Diagram showing how IR blasters work with smart or harmony hubs

As a result, you can then program your smart hub to control your TV – including channel changes, playback and more – without touching your TV remote. The Harmony Hub is a good example of this:

This actually offers a lot more smart control than a smart plug would.

Smart plugs and electric switches for other appliances

With all the above said, what above controlling… well, every other type of appliance with a smart plug? Unfortunately this comes directly back to the different types of switches that I covered earlier.

If your device has a physical (or mechanical) switch such as the following, it can be controller with a smart plug – just be sure to leave this physical switch ON:

A physical switch going to a side lamp light
A physical switch going to a side lamp light

However, if the device you want to control has an electric switch (such as the laptops and coffee machines I shown earlier), you’ll often be out of luck – especially since coffee machines don’t often come with power saving menus to change their power-on state!

Since these switches can’t be left ON all the time, they aren’t compatible with smart plugs. Hence you only have a few options here:

  1. Buy a device/appliance without an electric switch.
  2. Don’t use a smart plug to control this device.
  3. Use a smart plug, coupled with a SwitchBot.

Regarding point #3, a SwitchBot is a pretty handy device that can clip on next to a switch, and it will turn the switch on/off as part of an automation routine. This is pretty useful, but it has a few downsides:

  • You won’t be able to stick it onto all appliances and turn the switch on/off in the way you’d like (the appliance’s physical design might make it impossible to use the SwitchBot).
  • You need to control two devices (the smart plug plus the SwitchBot), not just one. Alexa routines are useful here, but they may not always be suitable.
  • The SwitchBot Bot ideally requires a hub, pushing the initial cost to over $50 – meaning you might be paying $60+ when you include the cost of the smart plug too.

Sorry! If the SwitchBot won’t work for you, you’re pretty much out of luck. I wish there was a magic way of fixing this issue, but it’s actually a fundamental problem with smart plugs – one that the marketing doesn’t often highlight, for some reason..!

Smart plugs are usually best for lights…

Since many household appliances have electric switches that prevent them being easily used with smart plugs, a more common use-case for smart plugs is with lamps – such as side and floor lamps (which nearly always have a physical switch):

A side lamp with an Amazon Echo Dot in-front of it
A dimmed side lamp, unfortunately not dimmed via a smart plug.

Indeed, Philips Hue’s smart plug specifically states that it’s for use with “any lamp”:

The back of the Hue Smart Plug box
The back of the Hue Smart Plug box mentions “Integrating any lamp”

Whilst Hue have probably only tested with lower powered lamps (instead of high powered household appliances) – and hence are partly protecting themselves by stating they’re only for lamps – it does highlight that smart plugs do have a limited use.

But of course, instead of using a smart plug with a lamp, you could instead just buy a smart light bulb for use in the lamp – meaning that you can turn the lamp on/off, and also dim it down (along with possibly changing its color, depending on the type of bulb).

And this to me is a big flaw with smart plugs: many appliances don’t work with them (due to their switch type), and lamps would probably benefit from a smart bulb.

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).

If you have any questions, feedback or suggestions about this article, please leave a comment below. Please note that all comments go into a moderation queue (to prevent blog spam). Your comment will be manually reviewed and approved by Tristan in less than a week. Thanks!

2 thoughts on “Smart Plugs & Devices With Electric Or Physical Switches”

  1. I want to use a smart plug of 10 amps. I only want to operate lights and fans. While using with smart plug, in order to make a particular light turn on and off, should the physical switch be kept in the ‘on’ position? Suppose it is in the ‘off’ position, the smart plug may not switch on? Please clarify.

    • Hi Ranganath, you are correct. If the power to the smart plug is turned off (due to the wall outlet’s switch being turned off), then it will not work at all. The smart plug will show up as unreachable on the app, and it can’t control the plugged-in device.


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