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cnh1995
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How did you get 470Ω here?
According to the simulation I ran, I got 400Ω there.
According to the simulation I ran, I got 400Ω there.
I read the color code on the resistor in the provided imagecnh1995 said:How did you get 470Ω here?
Oh..!Beause I could not theoretically determine R1. But once the zener is shorted, R1 won't be a part of the circuit, right?gneill said:I read the color code on the resistor in the provided image
Right. That's a valid approximation since the zener resistance is small compared to the other resistances in the circuit. So R1 will effectively be shorted, too.cnh1995 said:Oh..!Beause I could not theoretically determine R1. But once the zener is shorted, R1 won't be a part of the circuit, right?
Right!gneill said:Right. That's a valid approximation since the zener resistance is small compared to the other resistances in the circuit. So R1 will effectively be shorted, too.
In a more stringent analysis, one might find the resistance of the zener under operating conditions to be, say ten Ohms or so. Maybe less. Maybe a tad more. If it came down to such details then you'd look for a datasheet for the particular zener and pull up a value from there.
You mean (R3 ll R4) in series with (R2 ll R5)? Looks correct to me!mrowa196 said:How about R3 being in parralel with R4, but in series with R2 and R5 in parralel? That gives me something about 4.5 after quick calculation.
At point A: 5.6/(5.6+3.3)*6.2 = 3.90gneill said:Here's another rendering of your circuit with the components rearranged into a more common pattern:
View attachment 94003
If the zener is replaced by a short (not a bad approximation since it should have a zener resistance of just a few Ohms when in "zener mode") can you reevaluate your method for determining the Thevenin resistance?
gneill said:Here's another rendering of your circuit with the components rearranged into a more common pattern:
View attachment 94003
If the zener is replaced by a short (not a bad approximation since it should have a zener resistance of just a few Ohms when in "zener mode") can you reevaluate your method for determining the Thevenin resistance?
Redraw the circuit in post #46, suppressing the voltage source (ignoring its small resistance) and placing identified parallel resistances next to each other:nathsen said:Hi, I understand how R2 ll R5 and R3 ll R4 but what is the reasoning for R2 and R3 being in series and same for R4 and R5? Thanks
gneill said:Redraw the circuit in post #46, suppressing the voltage source (ignoring its small resistance) and placing identified parallel resistances next to each other:
View attachment 99869
Does that help?
Thanks again for your reply. So, to identify two components are in parallel I can identify that two components share the same pair of nodes. What's the definitive method to determine a component is in series with another? How do I come to the conclusion that they are in series from your diagram? Or are they only considered to be in series once both pair of parallel resistors are added?gneill said:Redraw the circuit in post #46, suppressing the voltage source (ignoring its small resistance) and placing identified parallel resistances next to each other:
View attachment 99869
Does that help?
It's the pairs of parallel resistors that are in series, not the resistors individually. The parallel pairs can both be simplified to single resistance values, and those resistors will be in series (share one node exclusively).nathsen said:Thanks again for your reply. So, to identify two components are in parallel I can identify that two components share the same pair of nodes. What's the definitive method to determine a component is in series with another? How do I come to the conclusion that they are in series from your diagram? Or are they only considered to be in series once both pair of parallel resistors are added?