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#2
July 9th 15, 06:27 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
rickman wrote:
On 7/8/2015 9:07 PM, John S wrote: On 7/8/2015 4:48 PM, wrote: John S wrote: On 7/8/2015 12:47 PM, wrote: John S wrote: So, at 1Hz the law has changed, eh? What new law do I need to use? To be pendatic, there is only one set of physical laws that govern electromagnetics. However for DC all the complex parts of those laws have no effect and all the equations can be simplified to remove the complex parts. In the real, practical world people look upon this as two sets of laws, one for AC and one for DC. A good example of this is the transmission line which does not exist at DC; at DC a transmission line is nothing more than two wires with some resistance that is totally and only due to the ohmic resistance of the material that makes up the wires. So, is .01Hz AC or DC, Jim? How about 1Hz? 10Hz? Where does AC begin and DC end? It is called a limit. If there is NO time varying component, it is DC, otherwise it is AC. Are you playing devil's advocate or are you really that ignorant? Then there is no such thing as DC because even a battery looses voltage over a period of time. DC voltage sources have noise. Are just being argumentative or are you really that ignorant? Even if you have a theoretical voltage source, there are no circuits (other than imaginary) that have been on since before the big bang and will be on for all time in the future. So what? Is there some point to all this other than to be argumentative? How long before someone brings up the fact that a resistor generates AC signals as some kind of straw man objection to DC theory? -- Jim Pennino |
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#3
July 9th 15, 06:46 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
On 7/9/2015 1:27 PM, wrote:
rickman wrote: On 7/8/2015 9:07 PM, John S wrote: On 7/8/2015 4:48 PM, wrote: John S wrote: On 7/8/2015 12:47 PM, wrote: John S wrote: So, at 1Hz the law has changed, eh? What new law do I need to use? To be pendatic, there is only one set of physical laws that govern electromagnetics. However for DC all the complex parts of those laws have no effect and all the equations can be simplified to remove the complex parts. In the real, practical world people look upon this as two sets of laws, one for AC and one for DC. A good example of this is the transmission line which does not exist at DC; at DC a transmission line is nothing more than two wires with some resistance that is totally and only due to the ohmic resistance of the material that makes up the wires. So, is .01Hz AC or DC, Jim? How about 1Hz? 10Hz? Where does AC begin and DC end? It is called a limit. If there is NO time varying component, it is DC, otherwise it is AC. Are you playing devil's advocate or are you really that ignorant? Then there is no such thing as DC because even a battery looses voltage over a period of time. DC voltage sources have noise. Are just being argumentative or are you really that ignorant? Even if you have a theoretical voltage source, there are no circuits (other than imaginary) that have been on since before the big bang and will be on for all time in the future. So what? Is there some point to all this other than to be argumentative? How long before someone brings up the fact that a resistor generates AC signals as some kind of straw man objection to DC theory? The point is that separating DC and AC as being ruled by separate "laws" is pointless. Just discuss the topic of interest rather than digressing onto pointless diversions. -- Rick |
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#4
July 9th 15, 07:16 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
rickman wrote:
On 7/9/2015 1:27 PM, wrote: rickman wrote: On 7/8/2015 9:07 PM, John S wrote: On 7/8/2015 4:48 PM, wrote: John S wrote: On 7/8/2015 12:47 PM, wrote: John S wrote: So, at 1Hz the law has changed, eh? What new law do I need to use? To be pendatic, there is only one set of physical laws that govern electromagnetics. However for DC all the complex parts of those laws have no effect and all the equations can be simplified to remove the complex parts. In the real, practical world people look upon this as two sets of laws, one for AC and one for DC. A good example of this is the transmission line which does not exist at DC; at DC a transmission line is nothing more than two wires with some resistance that is totally and only due to the ohmic resistance of the material that makes up the wires. So, is .01Hz AC or DC, Jim? How about 1Hz? 10Hz? Where does AC begin and DC end? It is called a limit. If there is NO time varying component, it is DC, otherwise it is AC. Are you playing devil's advocate or are you really that ignorant? Then there is no such thing as DC because even a battery looses voltage over a period of time. DC voltage sources have noise. Are just being argumentative or are you really that ignorant? Even if you have a theoretical voltage source, there are no circuits (other than imaginary) that have been on since before the big bang and will be on for all time in the future. So what? Is there some point to all this other than to be argumentative? How long before someone brings up the fact that a resistor generates AC signals as some kind of straw man objection to DC theory? The point is that separating DC and AC as being ruled by separate "laws" is pointless. Just discuss the topic of interest rather than digressing onto pointless diversions. Actually separating DC and AC is extremely practical which is why it is done in the real world. -- Jim Pennino |
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#5
July 9th 15, 08:11 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
On 7/9/2015 1:16 PM, wrote:
rickman wrote: On 7/9/2015 1:27 PM, wrote: rickman wrote: On 7/8/2015 9:07 PM, John S wrote: On 7/8/2015 4:48 PM, wrote: John S wrote: On 7/8/2015 12:47 PM, wrote: John S wrote: So, at 1Hz the law has changed, eh? What new law do I need to use? To be pendatic, there is only one set of physical laws that govern electromagnetics. However for DC all the complex parts of those laws have no effect and all the equations can be simplified to remove the complex parts. In the real, practical world people look upon this as two sets of laws, one for AC and one for DC. A good example of this is the transmission line which does not exist at DC; at DC a transmission line is nothing more than two wires with some resistance that is totally and only due to the ohmic resistance of the material that makes up the wires. So, is .01Hz AC or DC, Jim? How about 1Hz? 10Hz? Where does AC begin and DC end? It is called a limit. If there is NO time varying component, it is DC, otherwise it is AC. Are you playing devil's advocate or are you really that ignorant? Then there is no such thing as DC because even a battery looses voltage over a period of time. DC voltage sources have noise. Are just being argumentative or are you really that ignorant? Even if you have a theoretical voltage source, there are no circuits (other than imaginary) that have been on since before the big bang and will be on for all time in the future. So what? Is there some point to all this other than to be argumentative? How long before someone brings up the fact that a resistor generates AC signals as some kind of straw man objection to DC theory? The point is that separating DC and AC as being ruled by separate "laws" is pointless. Just discuss the topic of interest rather than digressing onto pointless diversions. Actually separating DC and AC is extremely practical which is why it is done in the real world. Sure, but separating the real and imaginary parts of impedance is SOMETIMES practical which is why it is done in the real world. |
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#6
July 9th 15, 08:38 PM
posted to rec.radio.amateur.antenna
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An antenna question--43 ft vertical
John S wrote:
On 7/9/2015 1:16 PM, wrote: rickman wrote: On 7/9/2015 1:27 PM, wrote: rickman wrote: On 7/8/2015 9:07 PM, John S wrote: On 7/8/2015 4:48 PM, wrote: John S wrote: On 7/8/2015 12:47 PM, wrote: John S wrote: So, at 1Hz the law has changed, eh? What new law do I need to use? To be pendatic, there is only one set of physical laws that govern electromagnetics. However for DC all the complex parts of those laws have no effect and all the equations can be simplified to remove the complex parts. In the real, practical world people look upon this as two sets of laws, one for AC and one for DC. A good example of this is the transmission line which does not exist at DC; at DC a transmission line is nothing more than two wires with some resistance that is totally and only due to the ohmic resistance of the material that makes up the wires. So, is .01Hz AC or DC, Jim? How about 1Hz? 10Hz? Where does AC begin and DC end? It is called a limit. If there is NO time varying component, it is DC, otherwise it is AC. Are you playing devil's advocate or are you really that ignorant? Then there is no such thing as DC because even a battery looses voltage over a period of time. DC voltage sources have noise. Are just being argumentative or are you really that ignorant? Even if you have a theoretical voltage source, there are no circuits (other than imaginary) that have been on since before the big bang and will be on for all time in the future. So what? Is there some point to all this other than to be argumentative? How long before someone brings up the fact that a resistor generates AC signals as some kind of straw man objection to DC theory? The point is that separating DC and AC as being ruled by separate "laws" is pointless. Just discuss the topic of interest rather than digressing onto pointless diversions. Actually separating DC and AC is extremely practical which is why it is done in the real world. Sure, but separating the real and imaginary parts of impedance is SOMETIMES practical which is why it is done in the real world. On rare occasions, but in the real world the DC analysis and the AC analysis are ALWAYS done seperately. A real world example: in the analysis of a circuit containing active components, first a DC analysis is done to establish the operating point of the circuit, then the AC analysis is done. -- Jim Pennino |
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