December 2010

Digital RF Level and Power Meter

A low-cost digital level and power meter, suitable for measuring RF signals ranging from 50kHz to 500MHz. As well as indicating the signal level in volts and dBV, it also shows the corresponding power level (into 50 ohms) in both mW and dBm on an LCD. PIC 16F88 based, with free source code downloadable from our Library and all constructional details provided in full colour.

Multi-purpose Car Scrolling Display (Part 1)

This mini dot-matrix scrolling LED display started as a car dashboard display, but can be used in any measurement or data logging application where 9-12V d.c. is available. Monitors up to six signals, eg speed, fuel, battery, cabin temperature, ECU data, and displays up to 10 computed values in a scrolling or static readout, on its 7 x 15 dot matrix LED. Two output channels for relays or buzzers, data logging is performed via USB upload to a PC.

12V Motor Speed Controller / 12V Lamp Dimmer

A handy pulse-width modulation circuit that can be utilised as a speed controller for a 12V 5A d.c. motor (continuous) or a dimmer for a 12V halogen or incandescent lamp up to 50W. MOSFET output stage. Single pcb to make a compact unit.

USB Clock with LCD Readout (Part 2)

This LCD clock will act as a stand-alone timekeeper using its internal battery backup, and will synchronise from your PC’s local time using an internet timeserver for accuracy. Displays 12 or 24 hour modes, time and date, and rechargeable battery condition indicator. Includes optional scroll modes and an optional dimming LED backlight.  PIC 18F4550-based, source code available from our Library.

This project requires a high degree of soldering expertise due to the use of several surface mounted devices.

In Part 2 this month the PC driver installation and setting up procedures are described. We also show how to synchronise your PC to an internet-based timeserver and how to sync.  the USB clock to the PC each time it boots up.

Teach-In 2011 (Part 2) – a broad-based introduction to electronics

Our educational electronic series Teach-In 2011 – A broad-based introduction to electronics. In Part 2 of Teach-In 2011 basic ‘discrete’ electronic components are introduced: resistors, capacitors, timing and delay circuits. Circuit Wizard software will help you to simulate and measure simple or more complex circuitry and we include a free demo CD on this months cover!

Teach-In 2011 is a unique electronics series offering hobbyists and students a superb, world-class opportunity to climb on board and enjoy the exciting and fast-paced world of electronics. Don’t miss this unique educational series.

Also in this month’s issue:

• Techno Talk – peering into tomorrow’s world, our column muses the potential of nano wires and all-photonic data switching.
• Recycle It! Our popular salvaging expert gives the low-down – or high beam – on HID headlights – high voltage high intensity discharge units and describes what can be done with them. (Handling them with care, for one!)
• Max’s Cool Beans Blog –  Max peers into a magical mirror!
• Circuit Surgery – Our in-house ‘circuit surgeon’ illustrates how to utilise LT Spice to display useful spectra.
• PIC n MIX A PS/2 keyboard and mouse interface for Propeller is described. Free code downloadable from our Library.
• Interface – the PC interfacing column explains how old relays still have their uses today! Circuits for simple transistor drivers are explained.
• Net Work – our Online Editor outlines his choice of anti virus program, and security measures to help guard your mobile phone data after loss or theft.