4 Channel DSP Amplifier with ADAU1701 & TPA3251

After having built my first class D amplifier, which is supposed to be a part of a new loudspeaker project, I thought it would make sense to include a DSP as a crossover and equalizer. I could build an active or passive crossover which I did in the past but I felt I needed a…



Multi speaker system for audiology lab

This is another project I did as a part of my civil service. The following requirements had to be met:

A linear actuator implementation to allow a non independent motion of each speaker
Two separate motion directions
Position accuracy of 1°
Repeatability of loudspeaker positioning
Tiltable frame
Total cost of all mechanical parts 3000 CHF (excluding labour)

The reason behind this project:…



Class D Verstärker mit TPA3251

Heute in Schmibens Bastelstunde: Ein 4 Kanal Class D Verstärker auf Basis des TPA3251 von Texas Instruments. Wo man früher noch dicke Kühlkörper brauchte, kommt man heute mit einem IC und einer Hand voll Hühnerfutter aus. Auch wenn Puristen und Audiophile auf Klasse A Verstärker schwören, nimmt die Verbreitung von Klasse D Verstärkern immer…



300W Konstantstrom LED Treiber (Buck Converter)

So, nach den vielen englischen Artikeln schreibe ich wieder einmal einen in Deutsch. Ich habe vor ein paar Wochen eine Konstantstromquelle für eine gepulste LED Leuchte “gebastelt”. Wie das manchmal so ist, hat mein Vorhaben nicht so funktioniert wie ich mir das vorgestellt habe, da die Energiedichte der Leuchte massiv zu klein ist. Naja immerhin…



The evolution of the brain

This article is written with permission of Dr. Nicolas Gerber (my boss during my civil service).

When I first got into this project I couldn’t believe that no one has ever built a brain with silicone, apparently there was no need for it. There was absolutely zero information in the net about…



Word clock on steroids

Nowaday it seems that everyone is building a word clock. The idea is nothing new anymore so I shouldn’t build one too, right? WRONG! Instead of going the easy route and rebuild a proven design I decided to create my own and beef it up a little. It’s definitely more expensive, more work,…



DIY IGBT controlled 1000Ws Flash Unit

The goal of this project was to develop a flash unit which is capable of withstanding continuous
operation over a “long” period of time before it needs maintenance. To be precise: 10 Million flashes of 1000J through a load of about 0.8Ohm. With a flash interval of 4 seconds this means about 1.5…



24S+ LTC6804 BMS with various Sensors and Logging Function

A few weeks ago I decided to build a Battery Management System based on the LTC6804-1. The reason that made me build a BMS was the lack of economically priced high grade systems that are also customisable and extendable. The last few Battery Management Systems I used were also absolutely not serviceable (sealed with…



4Motus DIY Überbike Part4: Jetzt mit Zulassung!

Nach Part3 folgt nun der endgültig letzte Part der 4Motus Überbike-Serie.

Es gab noch ein paar Änderungen am E-Bike, diese sind zwar klein aber trotzdem von Bedeutung. Wie schon in den vorigen Beiträgen erwähnt, war das Sattelrohr viel zu weit vorne. Dank eines Beitrags im Endless-Sphere Forum wurde der Hersteller des Rahmens auf mich…



Review: Smart-Prototyping.com PCB fabrication

This was my first time ordering from Smart-Prototyping.com. I was quite impressed by the speed they produced my PCBs. I ordered 75 PCBs with the following specs:

Max X-Dimension (cm): 15
Max Y-Dimension (cm): 15
Layers: 2
PCB Thickness (mm): 1.6
Copper Thickness: 1 oz
Surface Finish: ENIG
Solder Mask Color: White