I did a teardown of Homemate Touch FAN Touch Controller recently and at the same time I ordered Iotics Touch Switch Panel as well, the reason was it’s an Indian company product, they are manufacturing these Switches in India and this model has a lot of switches so I wanted to see how they have implemented the solution, which touch ICs they have used and which controller is used.
It has 6 ON/OFF switches for bulb and other load and 2x FAN Speed control (using relay). Triac based FAN Speed control is simpler but has humming noise issue at low speed mode and at low voltage.
Touch Panel provides both IR remote as well as Wi-Fi control mechanism. It costed me about 7400 Indian Rupees from Amazon.
Packaging looks really good to me.
User Manual and Support contact information is provided.
Custom built IR remote is included in the package.
Between the Fan symbols you can see window for IR sensor.
Front Panel quality is good, surface is very smooth and finish is also very good.
Back panel quality is also very good and feels like solid. Lot of information is printed on panel so that it is easy for electrician to understand and make the connections.
Once you remove the front panel, what you see is a lot of springs 🙂
These are nothing but touch pads extension with copper spiral wire. This helps you extend the touch and you can also place LED on the PCB at the area where user will touch the finger. Never seen before these kind of extension using copper spirals.
One thing I noticed, their PCBs where full of dust not sure how dust entered or they did not care about cleaning it during the production.
Backside of the Touch Spirals, you see ESP module from DOITING which basically does the Wi-Fi connectivity, acts as a main controller + touch sensing. ESP controller has touch sensing capable IOs
Another Atmel ATMEGA324 MCU is used, probably because they need more IOs for relay control.
LD01 is basically voltage regulator for 3.3V.
On the front side another thing I forgot to mention is the IR sensor(U$6), see in the image below.
You can have a closer look at the spirals and on the PCB, LED and current limiting resistor.
if you remove this PCB, there is another PCB below that, which is connected to the front PCB using multiple double row header connectors.
Good that they did not solder the PCBs like we saw on Homemate FAN Touch Controller.
The solder on the pads you see below are Power tracks from the relay to the terminal, this is common practice to add solder deposit on tracks to make it thick and hence improve current handling capability.
IC1 and IC2 are basically Relay driver, IC used is ILN2003.
On the right hand side of the PCB, you see a 4 pin bridge rectifier and U1 and 4 pin optocoupler, that is part of the AC to Converter Circuit.
Let us see the other side of this PCB.
In order to see the PCB on the other side, we need to remove it from the enclosure and to remove it we need open the screws from the terminal inputs.
As expected, on the other side of the PCB there are Power relays and Power supply section with transformer and capacitors.
Near relay you see high voltage orange capacitors those are polyester caps, along with high power resistors they form FAN speed control circuit. You can lean more about FAN Speed control using relays from this article.
Some close up images of the relays.
They have used Omron Relays, that’s very good quality relay.
Different type of relays on the PCB are because it can handle different load, like Bulb, heavy load, Power Switch Control and FAN.
On the back panel they have written everything what kind of load you can connect, it’s rating, etc.
This is the power supply section transformer and capacitor.
You can see solid brass terminal soldered on the PCB.
Design looks simple but it takes a lot of effort to build a product and able to sell it in the market.
I think they did a good job although scope of improvement is always there is any design you pick.
Certainly looks like manufactured in India and not something directly came from China.
So, that’s all in this teardown. I hope you have enjoyed reading and learned something new.
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I am currently working as an embedded systems design consultant helping companies build custom embedded products and develop test automation solutions for their PCBs.
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