Thread: What is a RELAY?!?

Tweet

yeah i ok i see i was just wondering

You can think of an electromechanical relay as having a small solenoid inside of it, which acts to close and open another electrical circuit. (BTW: an open circuit is one that electricity cannot flow through because there is a break/gap/opening in it somewhere, while a closed circuit is one where electricity can flow.)

A solid state relay behaves like an electromechanical one in theory, though there are differences that can affect circuit design, which is well beyond the level of this conversation.

The BIG point to grasp is that a relay's switching is triggered by one type of electric current flowing to it's inputs (AC or DC current at whatever voltage/current specifications it has), while the circuit contacts that the relay switches open/closed are independent of that triggering circuit. This independence is important, because it allows one type of electricity (AD/DC, at whatever voltage and current) to control a completely difference type.

For example, on many Halloween projects, a small 5 volt DC current can be used to switch a much larger 120 volts AC current, used to light an electric lamp, say. Thus, relays are important in allowing digital logic circuits to control "real world" high current devices. It can also go the other way, allowing high current circuits to signal low current digital devices, when the roles are reversed.

That's my take, anyway.

ok i see i got this wiring diagram made up for one prop. IDK if i need a relay i dont think so
here u go




im a great artist

-BYH

That circuit would never work (and makes little sense, I'm sorry to say.) You cannot hope to tackle such prop control unless you acquire some basic electrical and electronics theory knowledge.

I'd first recommend that you get a good book (Radioshack?) You could also take a course , if that's an option. Even those 101 electric/electronic experiments kits are a great place to start for any beginner. (I just bought my nephew one.) Once you have the basics down, you'll be able to handle something more complex, like what you're describing.

I'm just speaking from experience, having taught myself (and shocked myself, and blown stuff up, etc.) Also be careful with anything electricity related, because you CAN KILL YOURSELF (I've been close.)

Good luck with the learning.

Actually, look into the prop-1 card from EFX-Tek. I think you are trying to perform some circuit timing that triggers from a PIR. This product would really take what you are trying to do to the next level, and without killing yourself or the passerby. Plus, their forum is great and Jon and the gang will even help the novice with BASIC Stamp programming. Good luck.

yeah ive looked into that. but im trying something new. i have basic eletronic skills ive built a "door alarm" in a course. ill post a pic. but i didnt figure out how to design it. i just built it and understood it. 1 sec ill get a pic

this is the door alarm. but i have one more thing i need a question on




this is my 50 5mm LED lamp
idk were to put my 100ohm resistors or can i put a 1000ohm resistor at the begining