Hobby Projects - Insulation tester, LED Circuits, Meters.

Sunday, February 03, 2008

Twisted Pair - Learn Electronics Lessons

Learn Electronics Lessons and Information Pages

Find tools to help you work with resistors, capacitors, inductors, FETs, transformers, diodes, transistors, digital logic, TTL and CMOS devices. Learn how to use these in both AC and DC series, parallel and complex circuits. Explore Ohm, Kirchhoff and DeMorgan.

  • Capacitor Identification Codes
  • Metric Prefixes in Electronics
  • Dictionary of Electronics Terms
  • Circuit Analysis Puzzles
  • Ohms and Kirchhoff's

Saturday, February 02, 2008

PY2WM JK De Marco Projects

An Amateur Radio Enthusiast from Brazil. JK De Marco. In these pages Hams will find his ideas on QRP, Antennas and Complete circuits.

PY2WM JK De Marco Projects

 A 40 dB RF Attenuator

A 40 dB RF Attenuator

"To measure power of a high power transmitter, or to be able to observe the output signal on an oscilloscope or spectrum analyzer, it is necessary that the signal is attenuated in accordance with the instrument, while it must be ensured that the transmitter is "seeing" the correct impedance. So it requires an attenuator that works with three ports (input, output, and output attenuated), all while maintaining the correct impedance of 50 ohms.

The circuit assembly and is shown here in EMRFD and also in the QST. When properly calibrated can be used for precision measurements in section 0-500 MHz, or a a calibration capacitor C1, can be used for the range of 0-50 MHz with reliability."

Other Projects and Ideas
  • Simple Homebrew Coil Winding Machine
  • Qrp-Br Spectrometer
  • Simple ESR meter
  • Swr Power Measuring mW To KW
  • 5 Volts Reference Voltage Calibrator

Learning Circuits learn electricity

Learning Circuits learn electricity

If you are aged between 8 and 10 and wanting to learn about electricity and circuits then this is the place for you. Learning Circuits will guide you through 6 tutorials and then quiz you to test your knowledge.

Electricity and Circuits reinforces what your children learn from Physics at School, it takes the form of a virtual learning environment which reinforces Sources of Electricity, Circuits and Conductors, Changing Circuits andCircuit Diagrams.

Mikes Optical Timer Counter

"This page is the result of a lot of effort over the past couple years to develop a quality, inexpensive device to test shutters on the classic film cameras that I have been using..." .. Mike

Mikes Optical Timer Counter

Mikes Optical Timer Counter

Once built, this counter timer/device is easily adapted to a wide variety of applications, simply by construction of a new sensor.  Although designed to be used with photo-transistors, this device can also use relays, transistors and many other kinds of electrical switches as a sensor.

Other Projects
  • Model Railroading
  • 3 Transistor Audio Preamp for a Dynamic Microphone
Configuration and control of this counter/timer is through a RS232 port. Cable configuration for a usual PC compatible would consist of a null modem cable, with a female connector on the timer/counter end of the cable. The correct cable for a PC or usb to serial adapter with a DB-9 interface is listed in the bill of materials.