A Virtual Joystick – How Can You Make That ? – tutorial

01/31/2011

Hello everybody, this is a tutorial in which a virtual  Excel joystick controlled by mouse movements on a scatter chart has been demonstrated . While in operation, a macro updates the coordinates of the pointer in two spreadsheet cells. The two coordinates are then incorporated in formulas which limit the range of motion of the joystick. Just like a real device the stick head movement is confined within a square (with a side…

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Modeling a Three-Pendulum Harmonograph – tutorial: part #2

01/23/2011

Hi guys, here is the second part of a tutorial describing the matematical equations used in modeling a three-pendulum harmonograph (automatic drawing machine). It pertains to the second version of the model. This section describes the kinematic equations involved in the articulated linkage mechanism on the top of the table, the custom spreadsheet functions used in the model and some overall considerations about the partition of the spreadsheet.  This is an…

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Modeling a Three-Pendulum Harmonograph – tutorial: part #1

01/19/2011

Hi guys, here is the first part of a tutorial describing the matematical equations used in modeling a three-pendulum harmonograph (automatic drawing machine). It pertains to the second version of the model. This section refers only to the kinematic equations for the movement of three pendulums. A second section will be published later and it will describe the kinematic equations involved in the articulated linkage mechanism on the top of the table,…

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Creating a Digital Clock #1 – sprite generation

01/06/2011

Hi guys, this is part #1 of a tutorial showing how to generate sprites used in a digital clock model. Sprites are typically simplified images (usually two-dimensional) which are used to replace complex but remote 3D-objects in an image. When an object is far away from the viewer a three-dimensional representation is not necessary since the eye cannot see all the details, therefore the object is replaced with a much simple object…

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How to Model a Basic 2-body Planetary System

12/23/2010

Here is a tutorial explaining how to model a two dimensional  2-body planetary system in Excel. It uses the Euler method of integration. The tutorial starts with explaining the simple newtonial laws acting on the two planets. There are essentially just two forces acting on each body at any time: the inertia and the gravitational attraction. During each small time step, from the distance between bodies we can calculate the gravitational…

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Introduction to Numerical Methods – Basic Filters #2

11/09/2010

This post shows the steps for building a first model of a single pole RC high pass filter (HPF) in Excel based on numerical solution using the finite difference method. It is quite elemetary to undersand, try to go through the proof regardless of your background. [sociallocker][/sociallocker]

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Introduction to Numerical Methods – Basic Filters #1

10/22/2010

This post shows the steps for building a first model of a single pole RC low pass filter (LPF) in Excel based on numerical solution using the finite difference method. It is quite elemetary to undersand, try to go through the proof regardless of your background. [sociallocker][/sociallocker]

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