10/24/06

Current Sensors

How folks, I've been quite busy with teaching and my day job, therefore, the blog has not been updated on weekly basis. Sorry to all that have been waiting on what's been happening in Don's World. The electronics development projects at Hunter Fan have been pouring in and so short of time during the work day to start them, so I've been doing a little bit of "Maker" Hacks here and there at home to keep my head above water. One of the projects I'm working on (unfortunately I can't divulge it because of Hunter Fan's IP associated with device) involves using a current sensor for no-invasive detection of amperes. About 2 weeks ago, I purchased some current sensors to explore their electrical characteristics and possible inclusion for this electronic device I'm working on. The company is called Energy Science/Amploc located in Goleta, CA. They have several Hall Effect Sensors in various sizes and current ratings for measuring ac, dc, and complex waveforms. In my Office/Lab I was exploring the AMP Series (25Amp rating) of Current Sensors and developed this basic circuit for testing and evaluation.

                                                                                  

The cost of the sensor is about $12.00 which is a little pricey, therefore I recommend buying 2 or 3 spares for future sci tech or robo-gadget projects. This circuit would be a great with a Handy Cricket, LEGO RCX, or a ZigBee Demo Kit for detecting current non-invasively. Also, on the website there's a Engineer's Handbook explaining the basics behind the Hall Effect and how Energy Science/Amploc sensors can work in a Open or Closed Loop circuit configuration. I'll have additional information on about Current Sensors in a future blog entry.

 

10/09/06

The Solderless Breadboard

In capturing electronic circuit ideas for sci-tech or robo based gadgets, the solderless breadboard is an indispensable development tool. I've been using this electronics prototyping tool since 1978 and I several variations based on project requirements. In writing the two LEGO Mindstorms Books: (Interfacing and Mechatronics) all control circuits were built and tested using a Radio Shack Electronics Learning Lab Solderless Breadboard! The solderless breadboard allows for quick changes to be made to an electrical or electronic circuit based on the spring clip - wire insertion method for making electrical wiring connections to transistors, resistors, capacitors, relays, and ICs. Depending on how the wiring is done, the solderless breadboard can be placed into a Hobby Box for the final Electronics Hardware prototype. This rapid prototyping tool not only allows electronic design concepts to be captured and validated easily but also reinforces component packaging and pin identification as well. For the budding sci-tech and robo gadget builders I highly recommend building simple electrical circuits using the solderless breadboard for prototyping familiarity and circuit construction training. Also, reading circuit schematic diagram skills will be enhanced as well. With additional practice, you'll be ready for more complex electronics hobbyist projects in no time. Happy Solderless Breadboarding !!!!

                                               

                                               Hobby Electronics Frequency Counter using a Vector Prototyping Board

 

10/03/06

Digital Circuits     

Microcontroller Development boards like the Basic Stamp and the Handy Cricket make sci-tech and robo-gadget controls easy to build, digital circuits should not be discarded into the garbage. First of all, the Basic Stamp and Handy Cricket development boards rely on digital circuits for I/O interfacing to the real world. Also, microcontroller development boards can be enhanced by digital circuits because of the binary processing that both solid state devices use for connecting to the real world. The Digital Electronics II course I'm teaching at ITT Tech allows me to show the students how the course material can be modified with the aid of either the Basic Stamp, LEGO RCX , TI Graphics Calculator, or Handy Cricket microcontroller based development boards. To illustrate this concept, an expensive robot controller can be built using a basic digital counter/timer and a Handy Cricket. The system partitioning scheme consist of using a digital counter/timer to generate a control command signal after a count sequence of 9-0 is complete. Instead of activating a buzzer with completion of the count sequence, the control command signal will be fed to the Handy Cricket for a microcontroller control actuation of a small dc motor. The Handy Cricket is basically a "Smart Motor" Driver for robo-gadget devices. The building blocks for this controller consist of a Digital Counter/Controller and the Handy Cricket/Smart Motor Driver. I provide a complete schematic of the Hybrid Robo Controller in a future blog posting.