xiaobai00 Posted May 10, 2007 Report Share Posted May 10, 2007 need help from u guys, please. A million thanks if can help. =(i have problems of this circuit layout.1) what's the purpose for dotted line between pin 12 to 11? But the ic is ULN2003. Is the dotted line meant to be repeated the circuit as in pin 10?2) Is the relay RL7 example is included with the switch (S7)?3) Do relays have ohms reading, example 200ohm, 12V? I dont understand well, sorry. 4) What is the meaning of N and PH bottom of the image? Quote Link to comment Share on other sites More sharing options...
KF4SQB Posted May 10, 2007 Report Share Posted May 10, 2007 The dashed lines indicate that two sets of contacts operate "together". In other words, looking at the "appliance#7" part of the circuit in question, the contacts on the right and the contacts on the left are part of the same relay. For instance, both sets of contacts in a DPDT relay. The dashed lines going from the coil of "RL7" to the contacts above it are to signify that those contacts are operated by that coil, if I'm not mistaken.As for the "N" and "PH" at the lower right, I believe they would stand for "Neutral" and "PHase". Quote Link to comment Share on other sites More sharing options...
LostViking Posted May 22, 2007 Report Share Posted May 22, 2007 The last reply is partially correct in that the lines horizontally mean the contacts move together. The original question was not this.The lines you are asking about indicate that the contacts are activated by the coil that the dashed lines are pointing at. This is very common in schematics where the contacts may be drawn in one place and the circuit that activates the coil is somewhere else. Quote Link to comment Share on other sites More sharing options...
KF4SQB Posted May 23, 2007 Report Share Posted May 23, 2007 LostViking, I said that, if you had read my entire post.To answer the rest of the original question, "S7" would enable you to 'disable' "RL7" by opening it's common connection, thus preventing it from operating. Also, yes, relays are sometimes rated by the resistance or reactance, both measured in "Ohms", of their coil. Use Ohm's law to determine what resistance/reactance can be used at what voltage levels. Quote Link to comment Share on other sites More sharing options...
LostViking Posted May 23, 2007 Report Share Posted May 23, 2007 My bad, I must have skipped over that last line. Sorry. Quote Link to comment Share on other sites More sharing options...
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