having trouble finding these schematic symbols...

Thread Starter

Schematic unknown

Joined Jan 12, 2014
3
I am studying for a test and I am having a hard time finding what symbols C, H, K and L are. I have found a few symbols for motor and generator that are similar to C but I can't be sure. If anyone has any info I am grateful! 20140112_174341.jpg
 

DerStrom8

Joined Feb 20, 2011
2,390
C should have more markings. You are correct, it has the same shape as both a motor AND a generator. Might want to speak with your teacher about that. H is an older one that I haven't seen in years. I'm hesitant to give you the answer though. How do I know you're not doing homework, or even taking the test now?

Can't say I've ever seen K, but you should definitely know L.

EDIT: I take that back about L. I don't see how it's different from a standard resistor....
 

Thread Starter

Schematic unknown

Joined Jan 12, 2014
3
Well, the test is for a job and I dont take it until Thursday at a testing center, and so I also dont have a teacher to consult :(. I'm just working with a study guide and a textbook, electricity principles and applications by fowler 5th edition.
 

DerStrom8

Joined Feb 20, 2011
2,390
Okay, fair enough.

Once again, C should have more markings. Usually it would have a "M" inside the circle for a motor or a "G" for a generator. I have also seen some meters shown that way, with a "V", "A", or "Ω" depending on whether it's a voltmeter, ammeter, or ohmmeter.

H is a lamp, usually an incandescent light bulb.

Again, I have never seen K before, and L looks like just another resistor to me. Not sure why there's two of them. Perhaps one is wire-wound and one is carbon-film? Just guessing here, don't take my word for it.
 

MaxHeadRoom

Joined Jul 18, 2013
21,594
C usually indicates a DC motor or Gen, for AC motor the symbol is different for both 1ph and 3ph motors.
As mentioned the H could be a fusible link or lamp filament.
K is an overload device used on a contactor etc, the symbol is a bit deceiving at it does not usually open the circuit itself, it thermally or electronically trips a contact which opens a coil of the controlling device as opposed to a fuse.
L could be a lamp also, as it is enclosed in a circle, if it had a T on it, it would conform to the JIC symbol for thermistor.
Max.
 

WBahn

Joined Mar 31, 2012
26,268
L is most likely a device that relies on a variable resistance. An example would be a light-dependent resistor or a thermistor. There would normally be some indication, such as a letter, indicated something more specific.

I don't know that I agree with your notation for A. That symbol just strikes me as being a generic symbol for a passive component, again with supplemental markings giving more details.

The symbol E is just a switch. It is neither open nor closed, it is just a switch. If it were a momentary switch, then it would be necessary to be able to determine if it is normally open or normally closed.
 
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