Rc Definition and 643 Threads

rc (for "run commands") is the command line interpreter for Version 10 Unix and Plan 9 from Bell Labs operating systems. It resembles the Bourne shell, but its syntax is somewhat simpler. It was created by Tom Duff, who is better known for an unusual C programming language construct ("Duff's device").A port of the original rc to Unix is part of Plan 9 from User Space. A rewrite of rc for Unix-like operating systems by Byron Rakitzis is also available but includes some incompatible changes.
Rc uses C-like control structures instead of the original Bourne shell's ALGOL-like structures, except that it uses an if not construct instead of else, and has a Bourne-like for loop to iterate over lists. In rc, all variables are lists of strings, which eliminates the need for constructs like "$@". Variables are not re-split when expanded. The language is described in Duff's paper.

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  1. D

    How Do Scale Calculations Affect RC Car Physics?

    Hello All, I'm doing some fun at home experiments with my 1:6 scale RC car and I wanted do some camparisons with its full scale counter part. Mainly how jumping the two off a ramp (Duke's of Hazzard style). I wanted to know if you can help me with confirming some of my scaling...
  2. T

    Time constants, resistance and RC circuits

    I just need some help understanding some of the theory behind these.. Can anybody help explain the relevance of a time constant in an RC circuit and why the time constant increases as resistance increases? Thanks in advance:blushing:
  3. O

    A (probably) simple RC circuit question

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  4. D

    Engineering RC Circuit + Dependent Voltage Source

    Homework Statement http://img167.imageshack.us/img167/7747/picture2mg7.png Homework Equations iL(t) = current through inductor Using The Step by Step Method: Assume the solution iL(t) = K1 + K2*e^(-t/tau) where K1 = iL(infinity) and K2 = iL(0+) - iL(infinity) so, Assume the...
  5. D

    Engineering Solving RC Circuit Pulse with Step-by-Step Approach

    Hi, I have this problem to do for HW. I did what it asked for, or so I think. I think I may have made a mistake somewhere, it's telling me its not correct. Can you check it out? BTW, I have to use the step by step approach. I'm assuming my solution will be v(t) = K1 + K2 * e^(-t/RC). I then...
  6. D

    Engineering RC Circuit (Quick Glance please, mostly theoretical)

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  7. B

    Applying a square wave (from 0 to 5V) on a RC circuit

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  8. J

    Understanding Charge Formulation in Discharging RC Circuits: A Quick Question

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  9. M

    Calculating Phase Shift for a Series RC Circuit

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  10. S

    RC Circuit Problem: Find I1, I2, I3 and Q

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  11. B

    Help designing a RC passive high pass filter

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  12. R

    Maximizing Bandpass Filter Bandwidth: Practical vs Theoretical Approaches

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  13. K

    Problem about rc and lr circuits

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  14. A

    Cascading RC circuit w/ DC voltage. How will capacitors charging time vary?

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  15. Cyrus

    Cool RC Jet Stuff - Too Pricey for Me

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  16. P

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    Hi everyone http://img36.imageshack.us/img36/5721/wave7xq.gif .[/URL] I'm in a little bit of a mess and need some help with this lab write up. There's no way of getting in touch with my TA and my professor didn't prove to be that great of a help when I went to see him yesterday. Anyways, we did...
  17. T

    RC Time Constant and Average Slope

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  18. B

    Energy in a capacitor in an RC circuit.

    The question asks: For a charging circuit, the emf supplied by the battery is 200 V, R = 2*10^5\omega and C = 50 \mu F. Find: a) the time taken for the charge to rise to 90% of the final value b) the energy stored in the capacitor at t=RC c) the power loss in R at t=RC I've worked out...
  19. T

    How Does an RC Circuit Behave Over Time?

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  20. Cyrus

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  21. Cyrus

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  22. M

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  23. F

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  24. O

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  25. E

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  26. M

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  27. D

    How Do I Calculate Theoretical Charge and Discharge Times in RC Circuits?

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  28. N

    RC Circuits Lab: Get Help Understanding Charges & Discharges

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  29. C

    Solve Parallel RC Circuit Diff Eq | Current Flow

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  30. D

    Solve RC Circuit: Find Unknown Capacitor Value

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  31. S

    AC - frequency affect on RC voltage

    We observed that whenever the frequency of an AC circuit was increased, the voltage across an RC component changed shape. Specifically, 1) the trace lost its exponential growth and decay and instead had linear growth and decay, and 2) the voltage amplitude was much smaller. My guess as to...
  32. D

    What is the missing value in this parallel RC circuit problem?

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  33. E

    RC circuit with complex exponential

    I am stuck on this... Given a circuit: current source (Is(t)), R , C - all parallel; Is(t) = e^jt, Vs(t) = 223.6e^j(t - 63.43), Vs(t) is voltage across the current source, which I assume to be the same across R and C since they are ||. Find R and C. (ans: 500 Ohm, 4mF) My attemp was to...
  34. W

    Calculating Work Done with a Series RC Circuit with Variable Plate Spacing

    hey everyone just joined! glad to be here! i just don't get one part of the question and once i get it, i should be able to get the rest. A battery with an emf of 20 volts is connected in series with a resistor of 300,0000 ohms and an air-filled parallel-plate capacitor of capacitance 6...
  35. K

    Solving an RC Circuit with 68.0% Charge in 0.980s

    A capacitor in an RC circuit is charged to 68.0% of its maximum value in 0.980 s. What is the time constant of the circuit? >> I know the time constant is equal to Q/(Q/t) and that t = 0.980 s. I also know that Q = CE and E is a constant. But they don't tell me the capacitance to use... Bah...
  36. J

    How Do Charges Distribute in a Series RC Circuit with Two Capacitors?

    A current is released from a 120 V battery. The current passes through a resistor of 1200 ohms and then the current splits into two different capacitors. C1=2.0 uF C2=3.0 uF. If there is no charge on the capacitators before the current is released, determine the charges of Q1 and Q2 on...
  37. V

    Strange resistor voltage curve in an RC

    Hello, My data gravely perplexes me. I've set up a simple series RC circuit with an AC emf of 14V @ 20Hz. Resistor and capacitor values are 3.9E4 ohms and 4.7E-5 farads respectively. Ideally, the voltage across the resistor should be a simple sine curve, since this is basically an RLC series...
  38. R

    What is a single pole RC filter?

    Im just trying to write a small introduction for my lab report due in on friday and while i have an idea in my head what it is, i just can't put in into words
  39. G

    Solve RC Circuit: Find Capacitor Value

    Hi, I am stuck on a question to work out the value of a capacitor, The Question is: A capacitor and a 2Kohm resistor pass the same current when each is separately connected across a 100Hz power line. What is the value of the capacitor?
  40. I

    Can RC Car Clear a 20' Ramp at Racing Speed?

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  41. H

    RC Circuit:placement of capacitor on circuit

    In a series RC circuit, why does the capacitor need to be placed between the resistor and ground, and not between the resistor and voltage source. I have looked everywhere to find the reason, so if you could help it would be appreciated.
  42. S

    What is the significance of the RC time constant in a simple RC circuit?

    Hello there, I m very new to the forum n doesn't know that much manners of this forum.. I actually want to do a question... we did a practical in our university in which we determined the unknown resistance by using a neon flash bulb... I have to submit a report on that..i have to...
  43. N

    How to use the RC ckt to make a filter?

    how to use the RC ckt to make a filter?? how to use the RC ckt to make a filter??
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