Re: relay modules?

On 10/04/2024 14:16, Chris Green wrote:

Mike Scott <usenet.16@scottsonline.org.uk.invalid> wrote:

Hi all. Two separate projects which will need a relay of some sort to
run from a Pi or similar.
>
I'm really looking for something plug-and-go rather than build-your-own
(especially item 2 below)
>
First is a dpdt relay to switch around 12-20 V at a couple of amps. spdt
are easy to come by; the only dpdt ones I've found are on aliexpress,
but their longevity is possibly open to question :-{
>

Try CPC (cpc.farnell.com), but you will probably need some sort of
'driver' between the Pi digital output and the relay coil.
Alternatively, as suggested here, a solid state switch or even an opto
isolator.
 

Second is something to switch mains safely - a full 13A to run a 3kW
heater. I've drawn a blank: best I can think of is to butcher one of
those wireless mains switch modules, which would at least provide a good
isolation gap :-)
>

Again CPC will probably have something, but again you'll need
something between the Pi and the 'whatever'.
 Are there not ready made relay modules for the Pi?
 

There are, but most are lower power and SPDT.
Which is why I built my own...
BUT although it would be a fun project, even getting hold of big solid state relays is difficult.
--
"First, find out who are the people you can not criticise. They are your oppressors."
      - George Orwell