TP-Link HS200 Add Three-way Capability




About: Electronic Engineer, Maker, programmer and artesanal beer lover

TP-LINK HS200 is a very nice product. It's cheap ($39), directly connects to wifi without any additional hub, the Kasa App is great and works with Amazon Alexa.

But sometimes you want to keep that three-way old school switch, and HS200 doesn't support this kind of installation. Now you can do it!

This instructable requires soldering know how and electrical installations. It's easy and cheap, but if you are not familiar with both, please do not proceed.

Just to remember, your HS200 warranty will be void :) Do at your own risk.

Step 1: Open the Unit

First step: Open the unit. There`s locks at the sides of the switch. Gently force the plastic and you`ll open it.

Step 2: Remove Green Wire, or Create Another Hole

For this modification you will need a hole to pass a pair of wires.

My installation doesn`t have the ground, so I removed the green wire, it`s only attached to a metal plate that makes contact with the switch housing in the wall (my housings are plastic, so it doesn`t make sense at all ;) )

Step 3: Prepare Electronic Parts

Well... you know how to use a soldering iron, right?

Here's all the parts that you need:

1x Optocoupler 4N25

1x 100uF x 16V (or 25V) electrolytic capacitor

1x 47KOhms 1/8W resistor (FOR 120V) or 100KOhms 1/8W (for 220V)

1x diode 1N4004 or 1N4007

You can spread the terminals of 4N25 optocoupler. Pay attention at the pin 1 indicator.

Step 4: Put All Together

Using your manual ability and a soldering iron, put all together following the schematic.

You can do it in any other way, but the second picture is my suggestion.

(please note that the capacitor on the second picture is 10uF, it's wrong! The correct is 100uF, otherwise you will have a lot of bounce with the new switch)

Step 5: Connect New Wires to HS200

Now pass white and blue wire of your circuit thru the housing hole.

Following the picture, connect blue and white wires of your circuit to HS200 control board.

Blue wire will connect to ground, and white will connect to main switch.

Step 6: Close the Unit and Finish All External Connections

Now you can close the unit.

Connect the diode terminal to the original HS200 white wire (neutral)

Then, carefully isolate every terminal independently, avoiding any short circuit.

You will end up with a new RED wire to use :)

Step 7: Connect Your Unit

The schematics show how your three-way circuit should look, and how you will connect your new hacked HS200.

HS200 will be connected as usual. But the red wire should be connected to the old three-way second wire.

At the other side, the first old three-way wire should be directly connected to phase, and you need to replace the standard switch to a pulsating one, connected as the schematics shows.

VERY IMPORTANT: The pulsating switch MUST BE at the side where you have the PHASE, and HS200 where you have the returning wire to the lamp.


Turn off energy BEFORE INSTALL




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12 Discussions


Question 5 months ago on Introduction

Thank you for this HS200 mod. Have I done something wrong? When I press and hold the momentary switch then my HS200 toggles rapidly. I thought the capacitor and diode would rectify and smooth so that the optocoupler would see a steady positive, and so the HS200 would only switch once per switch press (and hold). Thanks for any help!


Reply 1 year ago

Do you know if there is a release date for this?


Reply 1 year ago

January 4th, 2018.


1 year ago

can i use 4N35 optocoupler? or what equivalent opto I can use other than 4n25?


1 year ago

What pulsating switch did you use? I cant find any momentary action switches designed for 3 way


1 year ago

For the white and blue wire attached to the Optocoupler, what gauge do we need? I don't want them to be overloaded and burnt out

1 reply

Reply 1 year ago

I would like to know this as well


1 year ago

Just revisiting this topic to clarify something. The momentary switch (pulsating) will send a brief line voltage signal through the newly created "red" wire to toggle the light on and off and update the state of the smart switch? I found this video regarding momentary switches, will this work for this setup.....


1 year ago

can modify HS 200 to 220v please


2 years ago

Can you explain what a pulsating switch is, or provide a link/ part number, googling does not return anything that seams correct.

1 reply

Reply 2 years ago

the schematic looks like a momentary switch. Tryan Eaton 7521W or any number of garbage disposal switches.