Hobby Projects - Insulation tester, LED Circuits, Meters.

Wednesday, April 24, 2013

Experiments with the LM2575

The standard buck regulator circuit delivers a +5V output. This is a rather straightforward circuit and will operate with a wide spread of component values. Optimal values should be selected however to get minimal ripple, minimal noise to the power source, maximum efficiency etc. Note that the quiesent current is about 10 to 14mA.

Experiments with the LM2575

Here is a nice way of using this regulator, this can be used for CMOS opamps as you have a -5V too. That means a portable instrument may find this design useful.

The TI Datasheet Layout Guidelines

LM2575 Switching Regulator
LM2575 - Step-Down Adjustable Voltage Switching Regulator with Output Enable

 The Spirit of Hacking and Fixing, Giving back Life to Old Instruments.

Fluke 8050A LCD display replaced with LED seven-segment

"Recently I was able to cheaply buy a second hand Fluke 8050A made in the early eighties. It is a nice 4.5 desktop digit meter, but a typical problem seems to be that the LCD wears out and goes black. Replacement LCD displays are hard to find, not cheap and probably lead to similar problems in due time."

Friday, April 19, 2013

Paul Falstad EE Applets and Tablet Apps

"These are some educational java applets I wrote to help visualize various concepts in math, physics, and engineering." - Paul Falstad

Electronic Educational Applets - Paul Falstad
  • Math and Physics Applets - MyPhysicsLab - Physics Simulation with Java.
  • Index of Circuit Examples - Demonstrates various electronic circuits.
  • Digital Filters - Filters digital signals and plays the output on your speakers.
  • Acoustic Interference Applet - Audio interference between your speakers.
  • Waveguide Modes Applet - Electromagnetic waves in a waveguide.
  • Antenna Applet - Generates antenna radiation patterns.
Analog Circuit Simulator Applet - Demonstrates various electronic circuits.

"This java applet is an electronic circuit simulator.  When the applet starts up you will see an animated schematic of a simple LRC circuit. The green color indicates positive voltage.  The gray color indicates ground.  A red color indicates negative voltage.  The moving yellow dots indicate current."

Derivative Works

iCircuit is the easy to use electronic circuit simulator and designer - the perfect tool for students, hobbyists, and engineers.

Its advanced simulation engine can handle both analog and digital circuits and features realtime always-on analysis. It is the perfect companion to students, hobbyists, and engineers.

Learn + Make + Teach Electronics at EveryCircuit

Electronics at EveryCircuit 

Build any circuit, tap play button, and watch dynamic voltage, current, and charge animations. This gives you insight into circuit operation like no equation does. While simulation is running, adjust circuit parameters with analog knob, and the circuit responds to your actions in real time.

Tuesday, April 16, 2013

Amateurfunkbasteln - Amateur Radio Crafts and Electronics

Amateur radio is a technical hobby. The attraction? To cover long distances with a low power radio to talk with other people, learn about their countries and cultures.

Amateurfunkbasteln - Amateur Radio Crafts and Electronics

But amateur radio also means tinker devices themselves, solder, apply electronics and learn something. In this sense, it can be a preparation for a technical career or even an engineering degree.

Use Google Translate, the pages are in German.

A Data Logger that records Slowly varying parameters, such as the temperature or decreasing the voltage of a battery. This copy records up to four measurements on parallel and saves it on a EEPROM.

Four Channel Data Logger - Amateurfunkbasteln

Four Channel Data Logger

It measures self-sufficient - without a PC - analog voltages (0-5V), it digitizes and stores the numerical value obtained in a separate memory. Later, after the measuring and recording phase, passes the data logger its information to the PC.

Friday, April 12, 2013

Tone generation using 89C2051 - AirBorn

This is a nice educational reference project based on 89C2051, an 8051 derivative. This uses the Uses analog switches to steer test tones and results. Programmed in assembler to produce pure 1khz tone. 

Tone generation using 89C2051 -  AirBorn

Tone generation using 89C2051 -  AirBorn

Using a multimeter

"The example meter that we are demonstrating is typical of many economical digital multimeters that you can purchase, hopefully these instructions will be of some use to you no matter what brand or type of meter you use. "

My Notes

Students and Hobbyists can study all the example projects and tutors in this site to become more skillful. They have pages that show how a PCB is made and things like Circuit Design and Prototyping. This Site also happens to be one of the oldest resources in the web for Electronic Embedded Designs.