As a general rule, power relays have a solid state that is different from some mechanical relays that can be found in very large electrical appliances (such as phase relays and circuit breakers in your home’s electrical circuits). Semiconductor time relays are much more reliable than electromechanical ones, mainly because they have no moving parts (therefore they are called “solids”). Because of this, they cannot capture during use.
The relay board will have an SSR that contains one or more transistors. This is what causes you to change the state from on to off. Modern time relays can withstand high electrical currents, which are very different from older relays. One of the best things is that regardless of the type of device you’re talking about, relays are always called relays. This can be very useful, for example, if you call technical support.
As already mentioned, its function is to turn something on or off. In technical parlance, this is called throwing contacts between the poles. There is other jargon you can find, like NC (normally closed) and NO (normally open), or DT (double throw) and CO (change). In general, the NO contact (normally open) is disconnected. NC is the opposite, which means that you have connected a circuit and are therefore active. Double Throw or Change Over connects two connected chains. Blackhawk Suppply can offer you a switch youuse so easily on the relay board basically switches the pole between normally closed and normally open or basically off.
The exact function that the switches provide on your particular relay card will depend on the application you are using. They can, for example, increase the amount of energy supplied to something with a weak source of energy (this is called amplification). They can also be used to control various circuits in the way they interact with each other. Of course, the simplest delay relays are those that simply turn something on or off at a specific time (for example, think of a sleep timer on your TV). Although all of this may seem very complicated, you generally don’t need to, thankfully.