No Power Warning

[SteamyTea]

2 hours ago, ProDave said:

Thereafter you leave the receiver powered

What happens if you don't.

[ProDave]

18 minutes ago, SteamyTea said:

What happens if you don't.

Then whatever you are trying to switch / indicate won't work.

[SteamyTea]

So the receiver looses the code set on the transmitter. Bit of a problem when sensing power, unless it has a relatively large back up battery.

[ProDave]

No it remembers the code, sorry if I did not make that clear.  The point was the receiver has to remain powered when you are expecting the transmitter to activate and turn it on.

[Onoff]

6 hours ago, ProDave said:

This is the transmitter unit I used https://www.ebay.co.uk/itm/433Mhz-Wireless-Transmitter-EV1527-Learning-Code-Encoded-for-Arduino-AVR/292030436727?hash=item43fe5ed577:g:QwkAAOSwB-1YpWii

 

You simply choose a code with the jumpers, then when you apply 5V dc, it transmits.

 

This is the receiver. https://www.ebay.co.uk/itm/1-Channel-Wireless-Relay-433MHz-RF-Remote-Control-Switch-Receiver-SRD-DC12V-10A/192470066162?hash=item2cd01c23f2:g:uJAAAOSwSfNal7~H

 

This runs from a 12V dc supply.  The first time you use it, you turn your transmitter on and then press the button on this module, that teaches it your chosen code.   

 

Thereafter you leave the receiver powered, and whenever your transmitter is turned on, this receiver module energises it's changeover relay that you can use to switch anything.

 

There are plenty of other variations on this theme available.

 

 Bloody Hell that's a steal! I'd not looked at the actual links before.

 

So the Tx can run off say a 9V battery as it's 5-12vdc? Turn it on with the NC contacts in the relay when mains is lost and it'll start transmitting.

 

The house end...a 12V wall wart to power it? The pcb relay powering something this:

 

https://www.ebay.co.uk/itm/2PCS-SFM-27-DC-3-24V-90DB-Intermittent-Beep-Alarm-Electronic-Buzzer-Sounder-FJ/143366277288?epid=0&hash=item21614bc8a8:g:GNUAAOSwSwNbTblp

 

All very cheap and doable at this rate. 

[ProDave]

Yes the price of some of these modules from China, it is not worth turning the soldering iron on to try and make your own.

 

I have ordered a little 12V power supply to complete my project.  Total cost of all parts still under £5  This is the 12V power supply I have ordered https://www.ebay.co.uk/itm/AC-DC-converter-power-supply-module-adapter-110V-220V-230V-to-12V-4RKUS/143262160732?hash=item215b17175c:g:ZAUAAOSwEB5c2nVv