So I’ve bought a relay which doesn’t insert onto my breadboard. The pins are slightly too large and the spacings are wrong. How should I tackle this? I feel like it’s a stupid question which probably has a really easy answer…but if you don’t know you don’t know.
It’s a K6B05.
Thank you.
@daneboomer, one option is to design a small PCB which holds the relay and put all connections out to a male header which can plug into your breadboard. That is overkill. The other option is to solder jumper wires to each the leads on the relay and plug those in to the breadboard. OR, you could just buy a relay breakout instead. 
Thank you. I may yet have to do the soldering of jumper wires. That sounds most practical. That would leave the relay sort of dangling from the breadboard. Is that right?
I would love to buy a relay breakout board instead but I have four cores and each one needs to switch a relay each. So it isn’t economical given that the breakout boards play host to four relays each? Thanks
@daneboomer, you could go with a dual-relay board like this (it was cheapest!):
Though it is powered with 5V, the opto-isolated input will work with the 3.3V digital output of a Core. 
What a beauty! Thanks! So with that…is it really just a case of provide it with +3.3v, ground, and then wire it up to a control pin and bob is my lobster? 
@peekay123, sorry, forgot to “quote” you, to notify you of a reply. Must get into the habit of that…
My advice: mount it dead-bug style with wires soldered to the pins.
Dead-bug (on it’s back, with the pins in the air) is good because it offers physical stability, soldering is a must for reliable connection. Just think twice about the pin assignments, because you will be looking at the part from below.
I dont know why most relays are like that! its a PITA. I found putting header pins into the breadboard in the closest matching holes, then soldering the relay to the header pins. some might have a big gap to bridge but it does the job.
@peekay123 thanks so much this is going to save me a lot of time and heartache! So I’ve found some of these in the UK (to save time on shipping), do you think they are the same type? i.e. each relay controlled by a single I/O pin being HIGH or LOW and also controllable by 3.3v rather than the 5v advertised?
Secondly question (only answer if you have time or can be bothered as I’m just curious) if these things are so cheap why would anyone buy the four-channel particle relay shield? Is that able to control greater current or something?
Thank you! Can’t wait to get started now.
@daneboomer, I would need to see the exact model to tell you if it will work. As for buying the relay shield, that should be obvious! First, there is an on-board voltage regulator so you can apply a range of DC power cubes (7-20V). Second, there is a nice socket for your Photon. Third, there is a nice prototyping area you can use. Finally, the whole thing is provided on a single slim and clean board. I rest my case. 
@peekay123 sorry, I edited my post a couple of mins after writing it to include the link to the listing. doh! Sorry again
@daneboomer, those boards use transistors to switch the relays and are not opto-isolated. There is no schematic but my suspicion is that the transistors/relays should switch with a 3.3v control voltage.
Hey @daneboomer.
One thing I’ve done before in the same situation is just take perfboard and drill/cut it to match. There are a lot of varieties to choose from. There are types with no copper, copper in strips like on your breadboard, or just where each hole is copper plated. You could use the relays you already have and the board is very sturdy. You could solder your Photon/Core to the board as well for a more permanent project, or use a socket.
Perfboard is pretty cheap. I did a quick search for ‘perfboard’ on Amazon.co.uk and found a bunch of options: http://www.amazon.co.uk/s/ref=nb_sb_noss_2/275-2481879-2834659?url=search-alias%3Daps&field-keywords=perfboard
Good luck!
Thanks @peekay123. Would you say opto-isolated relays are necessary? I’m trying to switch an AC doorbell and some DC 24v LEDs. Maybe some other bits and pieces. Nothing “big”.
@daneboomer, opto-isolation is just a way to get a transistor to turn the relays. The UK board you are looking at has drive transistors so that’s fine.