Tom writes:
Here’s a breakout board for those Songle SRD series relays that are so cheap on Ebay. It fits nicely on the Dangerous Prototypes standard PCB size DP5031.
Electromechanical relays are generally employ small signals to switch much higher voltages and currents. As a result, a nice big gap is required to insulate between the signal and load sides. It’s often a good idea to hive relays off to a separate board.
Via the project log forum.