April 2020

Ultra-low-distortion Preamplifier with Tone controls (Part 1)

This superb pre-amplifier also has tone controls, and infrared remote volume control and input switching and muting. It can be used with just about any power amplifier, either built-in or as a standalone unit. THD+N < 0.001%, typically <0.0003%. Straightforward to construct using discrete components on a thru-hole PCB. The circuit PIC 16F88 microcontroller, free hex file downloadable from the PE website.

iCEstick (Part 1) Introduction to programming FPGAs

Field programmable gate array (FPGA) ICs have been complex and difficult to utilise at hobbyist level, but thanks to the low-cost iCEstick development board from Lattice Semiconductors, helped along by some open-source software, beginners can now explore the use of these super-fast programmable devices that can be very much faster than microcontrollers. In Part One, the iCEstick USB development ‘stick’ and software are introduced.

Flip-dot Display

Flip-dots are alphanumeric dot-matrix displays that operate electromechanically. These types of traditional displays date back more than 50 years and are still in widespread use in many applications today.

They have high-visibility in all conditions and emit a very satisfying ‘click clack’ when changing state. Our constructional project explains their operation in full and provides a details of an expandable, stackable flip-dot segment, each 90mm high. Uses 5V/ 3.3V 4-wire serial interface and can be driven by a Micromite or Arduino. Demo of a single segment counting is available at http://www.siliconchip.com.au/Videos/Flip-dot

Also in this issue:

• Techno Talk – memories of Tandy batteries, and investigations into ferrite suppressors on computer leads
• Net Work –the new risk from web browser fingerprinting and more Internet news
• Circuit Surgery – troubleshooting problems with SPICE simulations
• Practically Speaking –  our practical, hands-on workshop series reminisces about traditional constructional techniques and offers an in-depth primer on surface mount technology (SMT).
• Make it with Micromite (Part 15) – having fun with a higher resolution TFT colour touchscreen
• Audio Out – The subject of analogue noise is discussed this month
• Visual programming with XOD – a thermostatic fan speed controller is created  using the XOD visual programming system
• Max’s Cool Beans – flashing LEDs and drooling engineers!

Next month

433MHz Wireless Data Extender; Bridge-mode AudiO Amplifier Adaptor; Ultra-low-distortion preamp with tone controls (Part 2); iCEstick FPGA VGA Terminal; Visual programming with XOD – a rate of change switch module.