# What is the english word?

1. Dec 1, 2005

### TSN79

Quite a simple question really; I'm just learning about some simple electronics, the link below is an exam from Norway. On page 4 there is a figure. I am simply wondering what this type of diagram, schematic or whatever is called in english? Knowing the english word would make it so much easier for me to find information about it on the web...

www.hist.no/aft/iet/elkraft/pls/eksamensoppgaver/eksopp091202.pdf

As long as I'm here, what is the R and S (top and bottom) on this figure? Do they stand for something? If you know of any sites where I can learn the basics of this type of diagram I would surely appreciate it, thx!

2. Dec 1, 2005

### mezarashi

From what I know, I don't think there is a specific name for that. The figure in page 4 looks like a circuit schematic. The one on page 7 is a timing diagram. R and S indicate two different potentials (voltages) driving the circuit. Usually Vcc and Vee or ground. The various elements are switches, implemented using transistors. I think it's more about understanding what the circuit does rather than how to use the schematic.

3. Dec 1, 2005

### Integral

Staff Emeritus
I would call the diagram on page 4, ladder logic. Generally they are show rotated 90deg with the power rails (R and S) running up the sides of the page. What is shown is a single "rung" of the ladder logic diagram. This is usually the starting point for creating a PLC program to control devices like the pneumatic schematic shown on page 1

4. Dec 2, 2005

### FredGarvin

The ladder logic is on page 3 of that text. Page 4 looks like some kind of cross between ladder logic and some sort of circuit diagram. I'd tend towards the latter. From what I can gather, it looks like (since I see the word motor in the question) it's some kind of circuit for controlling the direction of rotation of a motor. I'll have to ask some of the spark heads here to see if it looks like a familiar format.

5. Dec 2, 2005

### Averagesupernova

I'd say it's just a schematic. I don't know what the R and S stand for. K is often used as representative for a relay. S is for switch. The very top S is what looks to me to be a thermal overload switch commonly used on magnetic motor starters. The main motor current goes through a heating element. There is a bimetalic strip or something close to the element that moves when it is heated that is connected to the switch contacts. When the switch contacts open current is interrupted to a part of the circuit that controls the contactor that passes current to the motor. Is the schematic on this page part of something much larger? Have to brush up on my norwegian. Too bad all of my norwegian ancestors are gone.

6. Dec 13, 2005

### sjezdci

Relay logic

It is circuit diagram of relay logic, same as ladder diagram. It is European style of drawing of both, essentially same as in US, just turned 90º. Simbols for contacts and coils are different too.

7. Dec 13, 2005

### dlgoff

R and S are the 24vdc supply and ground. Page 4 diagram is a start/stop circuit for starting either of two motors, but not at the same time (S1 and S2). To stop, press S0.