remote control switch: problems programming remote controls

[Filippo52]

I found the product shown in the figure below on well-known Chinese sites



This is a very flexible product as you can pair up to 128 remote controls to a single receiver and control an unlimited number of receivers with a single receiver obviously not all close together and with overlapping ranges of action. Furthermore, in addition to the classic "turn on and off" functions, it is possible to switch on limited to "n" seconds.
The relay it is equipped with is very robust, they handle 30A which is certainly too much even for the terminals but 10-15A can pass easily.
This object has a price on European sales sites of around €20 with two remote controls while on the well-known Chinese site you can find it in the same configuration with two remote controls for €7. But that's not enough with the offers called "choice" you can pay even less than €2 with a single remote control. Really competitive price and the remote controls come with battery....
This is an ideal product to be used where you have a 220V AC power supply and you need to power a 220V lamp, a siren, a pump or anything at your command and obviously it is not easy to bring a pair of physical wires to create the command.
There is also a version with enhanced remote controls (obviously much bulkier which can work up to 1-2 km.

Unfortunately, as often happens, with the very low prices and Chinese products there is often an unpleasant surprise. I bought several and it went well, but on the third order I received two "sets" where it was impossible to program the receiving part; or rather, only the switching on programming took place but it lasted a few tenths of a second and then turned off again. In addition to this, leaving it powered on warmed up noticeably. I

I read that other people had had the same problem and I couldn't find any solutions.

I did tried to manage and to find the reason for the malfunction and I had noticed that the defective copies heated up the box in the "bottom" part
I Did open the switch see the photo



the heat was in correspondence with the red arrow where there is the part that creates the 12V DC voltage from the 220V AC to power the circuits.
The one indicated by the arrow had a particularly hot SMD diode next to it.
Making a comparison with the other working units I saw that the 12V voltage fluctuated and by measuring the component indicated by the arrow, which is an inductance, I found that it is not a faulty but an incorrect component. Its value is around 50uH while the one inserted into functioning devices is around 500uH. Replacing it will make everything work again.
A real movie which, due to lack of controls, makes a beautiful object unusable.
And perhaps this is the reason for the low price.
However, out of 8 purchased I only received two that didn't work and presented this problem

Hoping to have been helpful, I greet everyone

[madires]

Was featured by bigclivedotcom a week ago:

Inside a "30A" remote control - with schematic: https://odysee.com/@bigclivedotcom:0d/inside-a-30a-remote-control-with:f

[Filippo52]

Madires Thanks so much for the information.
Even if the electrical diagram is obtained with reverse engineering, the inductor is visible and the value of 1 mH (red circled) is indicated in the diagram.



As I said, on the two receivers that didn't work there were "only" 47 uH and it was foreseeable that they are not good. In the other two that I opened, and which worked correctly, I found 470uH.