Recent Changes - Search:
<^< C-R Discharging | Course index | Passive Wave-shaping Circuits >^>

Electronic circuits and components * Course Index * Introduction * About the Author * About this Course * Feedback * Course Navigation * How to use this Course * TINA * Locktronics

Fundamentals * Introduction: Fundamentals * Units and Multiples * Electricity * Electronic Principles * Electrical Circuits * Alternating Current * Assessment: Fundamentals

Passive Components * Introduction: Passive Components * Resistors * Capacitors * Inductors * Transformers * Batteries, Fuses, Lamps and Switches * Assessment: Passive Components

Semiconductors * Introduction: Semiconductors * Diodes * Transistors * Logic Gates * Assessment: Semiconductors

Passive Circuits * Introduction: Passive Circuits * Series and Parallel Connections * Kirchoff's Laws * Potential and Current Dividers * Passive Time Variant Circuits ## C-R Charging ## Worksheet: C-R Charging ## C-R Discharging ##

Worksheet: C-R Discharging ## Passive Wave-shaping Circuits ## Worksheet: Passive Wave-shaping Circuits * Assessment: Passive Circuits

Active Circuits * Introduction: Active Circuits * Power Supply Circuits * Operational Amplifier Circuits * Transistor Amplifier Circuits * 555 Timer Circuits * Assessment: Active Circuits

Parts Gallery * Introduction: Parts Gallery * Passive Component Images * Semiconductor Images * Other Images * Quizzes

(:Summary:Contains the 'action' links (like Browse, Edit, History, etc.), placed at the top of the page, see site page actions:) (:comment This page can be somewhat complex to figure out the first time you see it. Its contents are documented at PmWiki.SitePageActions if you need help. :) * Print (:comment (:if group Site,SiteAdmin,Cookbook,Profiles,PmWiki*:) (:comment delete if and ifend to enable backlinks:) * %item rel=nofollow class=backlinks accesskey='$[ak_backlinks]'% [[{*$Name}?action=search&q=link={*$FullName} | $[Backlinks] ]] (:ifend:) :) * Login

PassiveTimeVariantCircuits /

Worksheet: CR Discharging

<^< C-R Discharging | Course Index | Passive Wave-shaping Circuits >^>(:nl:)

Objective: To investigate the action of a C-R charging circuit when connected to a d.c. supply.
Underpinning knowledge: Capacitance, charge and voltage. Time constant.
Apparatus: TINA circuit file, or apparatus to make the following circuit.

TINA Circuit File: Click here to download circuit file
Initial Settings: C = 100µF, R = 1M&#937;, 10V d.c. Supply.
Requires: Paper, Linear graph paper, pen or pencil.
Instructions:

(a) Change the switch so the capacitor is connected to the discharge resistor. Then start the simulation in transient mode.

(b) Take readings of capacitor voltage every 20s from 0 to 200s and then every 50s from 200s to 400s. At each point, measure and record the capacitor voltage in a table.

(c) Plot a graph showing capacitor voltage, V'_C_', plotted against time, t.

(d) Determine the time constant of the circuit (C x R).

Observations:

Comment on the shape of the graph. Determine the time taken for the capacitor to fall to 37% of its initial voltage (i.e. 37% of 10V or 3.7V). Confirm that this time is the same as the time constant (C x R) for the circuit.

Further work:

Construct a tangent to your curve of V'_C_' plotted against time at t = 0. The line of this tangent should pass through 0V on the voltage scale at a time equal to the time constant (C x R). What can you infer from this?

(:nl:)(:table style="clear:both":)

(:Summary: Website page footer:)

Print - (:comment (:if group Site,SiteAdmin,Cookbook,Profiles,PmWiki*:) (:comment delete if and ifend to enable backlinks:) %item rel=nofollow class=backlinks accesskey='$[ak_backlinks]'% [[{*$Name}?action=search&q=link={*$FullName} | $[Backlinks] ]] (:ifend:) :) Search - Login

Page last modified on July 28, 2011, at 01:22 PM