PitelSPOT » Grant Pitel

PitelSPOT is Moving

Grant Pitel — Sun, 27 Dec 2009 18:57:09 +0000

Temporary Server Rack

PitelSPOT server will shutdown on December 31st 2009 and will not become active again until Janurary 6th 2010 (at earliest). We are moving from Illinois to New Jersey and are taking the server with us. We are also changing services from DSL to Cable. We are keeping out fingers crossed that cable upload speeds are faster than out current DSL speed. Comcast does not guarentee bandwidth like DSL does.

Visio Shapes and Engineering Template for Electrical Circuits

Grant Pitel — Thu, 18 Jun 2009 05:27:26 +0000

If you have ever used the the Electrical Engineer Library included with Visio, you will quickly learn just how crappy it is. Symbols do not align to the grid, they contain long connectors, and the shapes are just plain unprofessional. I believe the example image shown in Fig. 1 clearly explains my point. The circuit library I have been slowly building as a result could be useful to ECE students and practicing engineers. If you are a student and your department is part of the Microsoft Development Network (MSDN), which most are, you can get Visio for free.

Fig.1 Why Visio Library Sucks

The advantages of the PitelSPOT Electrical Shape Library and the PitelSPOT Engineering Template are:

Symbols align to a 0.1″ grid. This grid work great for those small double column articles required in IEEE journals and conference papers.
The Engineering Template will setup the grids and snaps for you. To use, go to File=> New=> New Drawing from Template=> then select PitelSPOTEngineeringTemplate.vst.
Symbols are minimal. Use the connector tool to join shapes.

The presently supported shapes are shown in Fig. 2.

Fig. 2. List of Included Electrical Symbols

Version History

06-17-09: FREE DOWNLOAD: PitelSPOT Engineering Template for Visio Version 1.0
06-17-09: FREE DOWNLOAD: PitelSPOT Electrical Shapes for Visio Version 1.0

The dowloads listed are for free. If there is a symbol missing, make your request in the comments below. Bribes/gratitude in the form of donations are welcomed via the Paypal link below.

Downgrade to Wordpress 2.8 – Revenge of the Permalink

Grant Pitel — Sun, 14 Jun 2009 15:09:52 +0000

Revenge of the permalink errors. A had a similar problem happen when I upgraded to 2.7.1, which I posted about here.

Downgrading to Wordpress2.7.1 was really simple:

Download the previous version.
Drag the files into your Wordpress installation directory.
Log-in into the admin menu.
Wordpress will request to automatically update your database. Agree to the update.
Everything should be back to the way it was. It was for me.

Readers, keep me posted on when this major bug gets resolved. Thanks.

Rapid Digital Design

Grant Pitel — Sat, 06 Jun 2009 00:43:13 +0000

This article covers chapter 5 of my dissertation.

    - Single-Phase Grid Connected Control
    – Direct Digital Synthesis
    - All Digital Phase-Lock Loop
    - Software and Hardware in the Loop Experiments
    – Rapid Control Prototypes and System Products

G. Pitel, “Fast power converters and rapid digital design,” UILU-ENG-2008-2509, CEME-TR-2008-02, December 2008, pp. 92-109.

Introduction & Power Electronics Modeling

Grant Pitel — Wed, 13 May 2009 01:05:40 +0000

Good news, my transactions was accepted–which means I can start letting dissertation chapters trickle out into Internet land. Enjoy.

This article covers chapters 1 and 2 of my disstertation. These chapters cover:

- Dissertation Introduction
- Voltage Source Buck Converter Modeling
- Boost Converter Modeling
- Voltage Source Inverter Modeling

G. Pitel, “Fast power converters and rapid digital design,” UILU-ENG-2008-2509, CEME-TR-2008-02, December 2008, pp. 1-14.

Wordpress Fixes for HTTP 500 and HTTP 404

Grant Pitel — Wed, 15 Apr 2009 02:28:52 +0000

This post adds to the collection of fixes for the dreaded WordPress HTTP 500 and HTTP 404 errors users can encounter after an update . In particular, the article targets the scenerio when default Permalink settings (e.g. http://pitelspot.com/?p=123) work, but not custom structures (e.g. http://pitelspot.com/2009/04/sample-post/) which produce HTTP404 errors. Below, I have summarize solutions that the community has offered and contributed my own fix — as I could not find it anywhere. These solutions are listed in order of frequency they were found.

COMMON FIXES FOR WORDPRESS PERMALINKS

(1) Go to http://yourdomain.com/wp-admin/options-permalink.php, click the Default radio button, Save Changes, restart Apache, verify that post links work, then revert to you original Custom Structure (e.g. /%year%/%monthnum%/%day%/%postname%/), Save Change, restart Apache, and hopefully it works.

(2) Delete the hidden .htaccess in your Wordpress root directory. If your folder has correct write permissions, WordPress will create a new .htaccess, otherwise it will report an error. Fixing write permission depends on you host OS .

(3) Make sure that your Apache settings file httpd.conf has directory settings similar to

    Options FollowSymLinks
    AllowOverride All
    Order allow,deny
    allow from all

(4) Make sure that LoadModule rewrite_module modules/mod_rewrite.so is enabled in Apache setting file httpd.conf (that was what was wrong with my server).

I hope this concise summary was useful. Please do not ask me personally what is wrong with your server as I am not an expert and there are just too many variables involved. Feel free to discuss your issues amongst other users in the comments.

PitelSPOT’s New Home–Skynet

Grant Pitel — Sat, 24 Jan 2009 01:11:01 +0000

In an effort to make my life easier I decided to put PitelSPOT on its own dedicated server. In the past, all my web applications were run from my workstation, which has obvious disadvantages. I appologize to all those cutoff mid-article because I was doing some routine MATLAB/Vista reboot. I wanted to share the hardware specifications, server features, and installed web applications.

Hardware
Intel Core i7 2.66 GHz, 130W, Quad-Core with hyperthreading (8 core equivalent)
6 GB of DDR3 memory
two 1 TB Hitachi hard drives
250 GB Seagate Barracuda hard drive
ASUS P6T Motherboard (16-phase VRM… covered in my dissertation)
rackmount case with 5 hot-swappable drive bays

Server Features
Shadow Copies – Every modification done to a file is backed up seamlessly. Can restore any intance of the file
Image Restoration – Recover entire OS and installed programs according to bi-weekly intervals
Off -Site Storage – Copy files to external hard drive and store offsite (when I remember).
RemoteApp - Load applications remotely within their own window. All application processing is performed on the server.
Consolidated Storage - All of Sheryl’s and my documents are stored in the same spot, regardless of which computer we use.
Virtual Machine Server - Emulate an entire computer in software

Web Applications
Wordpress Version 2.7
Gallery 2.3
Deki-Wiki Virtual Appliance
FTP Site

PitelSPOT is Getting a New Home

Grant Pitel — Sat, 10 Jan 2009 17:44:05 +0000

Expect server outages this week. PitelSPOT is getting a major upgrade that will be described in a later post.

Fast Power Converters and Rapid Digital Design

Grant Pitel — Thu, 01 Jan 2009 22:16:26 +0000

I decided to post my University of Illinois doctorate dissertation. If you have questions, please leave a comment below so we can have open discussions. This dissertation applies large-signal and time-domain models along with digital control to achieve fast control performance and to quickly test/design multi-block power controllers.
Fast controls are needed for motherboard level power supplies, called voltage-regulator modules (VRM), where CPU power specifications grow more stringent. Multi-block controls help interconnected power systems track numerous control objectives, such as those found in grid-interactive power electronics. The models used in the dissertation were derived using MathCAD, simulations in Simulink, and hardware experiments on a TI TMS320F2812 DSP. The main chapters are summarized below.

Chapter 2: Piecewise linear, bilinear, and steady-state power converter models.
Chapter 3.4: Minimum-time control / nonlinear-model predictive control.
Chapter 3.5: Parameter system identification using recursive-least squares algorithm.
Chapter 4: Programmable dc-dc converter system performance using active low/high-side damper resistors.
Chapter 5: In depth study of model-based techniques using a grid-interactive inverter.

I would like to thank National Science Foundation (NSF ECS 06-21643) and the Grainger Center for supporting the work. Also I would like to thank my adviser Prof. Krein and the members on my committee whose guidance was greatly appreciated. If you decide to reference this work, please use the official reference, G. Pitel, “Fast power converters and rapid digital design,” UILU-ENG-2008-2509, CEME-TR-2008-02, December 2008.

Download Link–The full document is coming January/February.

How to Make Neighborhood Electric Vehicles Legal in Your Town

Grant Pitel — Tue, 19 Aug 2008 05:11:26 +0000

Somehow, my wife and I managed to share a car for the past five years. This arrangment worked because we live in a small town, both work at the University, and are attached at the hip. However, I am about to graduate and will need a car to commute. My wife still has about a year before she finishes. It is hard to justfiy getting a second car for her short trip to work. I was ecstatic when she agreed to ride a neighborhood electric vehicle (NEV) into work, provided it met certain cosmetic criteria. My wife is a really good sport when it comes to my unusual habits. She has no shame tailing behind on my Go-Ped electric scooter while I bicycle into work. Her response to this new brainstorm should come at no surpise. The NEV fits her transportation needs perfectly, is inexpensive, low maintenance, and fuel-free. The rules on NEVs are governed by the city you live in. I was extremely disappointed to find the Cities of Champaign and Urbana do not allow them outside of the University of Illinois district.

I have contacted some city council members in hopes of bringing these enviroment- and energy-friendly vehicles to public streets. Below I am documenting the steps we have gone through so far, and will update it as new events occur. I encourage you contact your city council members to support NEVs in your town. This gesture is just a small step in ending our dependence on foreign oil. Thank you and I hope you find the items below useful.

NEV JOURNAL

(08-12-08) Sheryl called our insurance agent to see if they would insure an NEV. They confirmed that they insure NEVs but at a higher rate than cars due to their lack of safty features and limited availability of replacement parts.
(08-15-08) I contacted Champaign City Council, whose ordinances define where NEVs are allowed. The e-mail addresses and photos listed on the city council website suggested the members were very appoachable, and I found this to be true. Champaign also has an extensive database that lets users search previous minutes and agendas–an excellent resource for finding existing NEV ordinances.
(08-18-08) I recieved a reply from a member of the city council saying he was adding NEVs to the agenda. He stated that he personally supports allowing NEVs on public streets but expects opposition for their use outside the University District, and recommends that I e-mail the other council members.
(08-22-08) City council study session schedule approved for next week.
(09-08-08) City council is discussing expansion on 09-09-08.
(09-09-08) City council passed in favor of Neighborhood Electric vehicles eight to one. Stay tuned. Read the meeting summary (taken from the City of Champaign website).