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Electronic design and prototype development.

POUL PETERSEN - or PP - is a minor, highly specialized firm, exclusively dedicated to advanced electronic design and development - mainly within the analogue field of pro-audio and studio equipment.

One of my primary services is development of electronic appliances like Hi-Fi equipment, electronic cross over networks, navigational equipment for ships and laboratory equipment.
My contribution can be the entire product design - from product specification to production - or only a part of the design like for example PCB design. On this page, I will try to give an overview over a product development.

As most product developments are different, and as this page is held in general terms, the content should be considered as a guidance only.


Product design, step by step

This section describes some of the steps that can be part of a project design.
Product description.
The product description must contain a complete description of the product's features. The product description can be made by the customer, or can be worked out in cooperation between the parties.
Some of the points, that may be part of a product description, are listed in the Product description section further down this page.

Time schedule.
One of the 1st. points in a project design, is to establish a time schedule for the project.
In addition to establishing the time, where the development must be finished, the time schedule can also have a number of checkpoints during the development.

Initial user's manual.
During the product development, an initial user's manual is often a great help, and writing the manual in an early stage in the development phase may also catch some adverse product features; features that are difficult to explain may be unnecessary or implemented in the wrong way.

Mechanical design.
For prototypes and products with a low production volume, I can design, and to some extend, manufacture the mechanics from aluminum or plastic.
I also have a close cooperation with a number of mechanical workshops, so mechanical parts from almost any material can be realized.
For products with a high production volume, the manufacturer of the mechanical parts must be involved in the design process from the beginning in order to achieve the optimal solution.

Circuit design.
The circuit design can start from scratch, or be based on existing and proven circuit blocks.
Before circuit design starts, the main goal of the design must be established; this can be minimum cost, minimum size, visual impression, discrete component circuitry only, no overall feedback, best performance/price ratio - or any other parameters.

Circuit simulation.
Circuit simulation is used to verify that the circuit performs as desired and to establish the component tolerances required to meet the specification. During the simulation, it is also investigated how the circuit will perform under extreme conditions and during overload conditions.
In house developed software allows me to create simulation models from measured data, so special components,  where simulation models are not normally available, can be included in the simulation.

Initial microcontroller or PLD programming.
This is to establish the type and size of the programmable devices that are required. At this time, simulation is used to verify the function of the microcontroller or PLD. The initial programming also provides a microcontroller or PLD with sufficient functionality for circuit testing.

Circuit testing.
The circuit is tested under conditions as close as possible to how the circuit will be used in order to verify that it actually works as expected.

PCB lay-out.
Depending in the size of the project, this is a PCB for the actual prototype or, if the project is so large that more people must work on it, a number of temporary PCBs.

Prototype test and verification.
This is to verify that the mechanics, electronics and software works together as expected, and equally - or more - important, to verify that the final product works as expected seen from the user's point of view.

Assembly instructions for manufacturer.

Circuit description.
This is a summing up of notes made during the design process, typically describing why things were done the way they were. These notes can be are very useful if the product is to be modified at a later time.

Test procedure description.
This describes how to test the final product in simplest possible way to verify that all parts of the product performs as required. If the product testing is done by automatic test equipment, this also involves writing software for the test equipment.

Product and circuit description for marketing purposes.
This is a non-technical description of the product functionality and a performance description according to the standards normally used for the kind of product.

Product description

In order to obtain the shortest development time, as much information as possible should be included in the product description. This list shows some of the points that could be relevant for a product description.

The customer's expectations to the product, like:
Best price/performance ratio.
No overall feedback.
Discrete only circuit.
Easy to disassemble and repair.
Few, but expensive, components.
European components only.

Commercial items like:
Production volume per year.
Production location.
Maximum acceptable component cost.
Use of already stocked components.

Technical items like:
Approval requirements.
Operation temperature range.
Minimum supply voltage.
Maximum supply voltage.
Maximum supply current.
Enclosure design and material.
Source transducer type.
Source impedance.
Input impedance.
Voltage input.
Current input.
Balanced input.
Unbalanced input.
Transformer balanced input.
Maximum operational input signal.
Maximum non-destructive input signal.
Maximum noise.
Maximum distortion.
Maximum offset voltage or current.
Load type.
Load impedance.
Output impedance.
Voltage output.
Current output.
Balanced output.
Unbalanced output.
Transformer balanced output.
Maximum required output signal.
Maximum allowed output signal.
Voltage or current gain.
Input signal bandwidth.
Output signal bandwidth.
Bandwidth for control inputs.
Clickless signal path switching.
Path switching setup and changeover times.
Filter frequencies and bandwidths.


Most of the tools I use are PC based, PC controlled or can transfer the measured data to a PC. This allows me to save a large number of calculated and measured data for later reference or for use in project documentation, user manuals and service manuals.
The list below shows some of the tools that I use for product development.
PSpice circuit simulator
The industry standard in circuit simulators. Features includes DC, AC and transient analysis, worst case analysis, monte carlo analysis and behavioral modeling.
A very comprehensive PCB design software package.
Microchips PICstart
A simple, yet powerful, PIC microcontroller assembler, simulator and programmer.
Audio Precision System Two Dual Domain
One of the most comprehensive and accurate audio frequency analyzers available.
Features include:
  • Analogue, digital or mixed analogue/digital signal generation and measurement.
  • <0.01 dB frequency linearity.
  • FFT analysis of analogue or digital signals (analogue signals up to 80 KHz / 16384 samples).
  • Jitter generation and measurements for AES/EBU and SPDIF digital audio interfaces.
  • Multitone signal generation and measurement.
  • Quasi-anechoic acoustical (MLS) measurements.
More information on Audio Precision's products can be found at http://www.audioprecision.com.
HP 54645D
A 100 MHz digital sampling oscilloscope with 2 analogue channels, 16 digital channels, 1 Msample memory and a 100 MHz / 1024 point FFT analyzer.
Tektronix 7603
A 100 MHz analogue oscilloscope with 2 high frequency inputs and a high sensitivity differential amplifier input.
V Line
Product design
PCB lay-out
V Line
Hi-Fi products
PA products
Recording & studio equipment
Test & measurement equipment

Poul Petersen, C/Faya 14, 35120 Arguineguín, Las Palmas, Spain.
Tel/Fax: (+34) 928 152 807, Skype: poul.petersen.gc.
http://www.poulpetersen.dk, E-mail: pp@poulpetersen.dk
Copyright © Poul Petersen 1998 - 2015. Valid HTML 4.0!