printed-circuit boards designed by me
| what
| when
| parameters
| in service life
| images
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| enhanced I/O for data-acquisition of Gonio-Photometer
| 2013+
| work in progress
| development/active
| -
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| multiple custom signal distribution boards pgII gonio-photometer,
| 2012+
| interface cards for signal distribution between COTS I/O cards and internal electrics,
mostly passive, although tightly packed with connectors and tracks,
special thanks to the folks at kicad for a neat schematic and PCB program
| active at pab-opto and other research labs worldwide
| -
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| custom pre-amplifier and A/D converter for pgII gonio-photometer
| 2008+
| modular, > 7 decades, digital output
back doing the PCB layout myself on Linux
| active at pab-opto and other research labs worldwide
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| pre-amplifier for pgII gonio-photometer
| 2005-2007
| 4 channels, 7 decades, analog output
circuit design by pab, external PCB layout
| 2+ years at pab-opto and in productive industrial use
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| analog/digital input module for an Eltec SAC700 board
| January 1991
| 4x 12bit, 12bit parallel out
HP's electronic CAD program "DCS" at FhG-ISE, SMD bus driver components, PAL address decoding by Bernhard Tritsch
| 12 years at FhG-ISE
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| digital opto-coupler board
| August 1989
| de-coupled all I/O signals to pg1 gonio-photometer
done with my own small X11 layout program, since I found hand-drawing dual-layer PCBs a bit tedious
| 12 years at FhG-ISE
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| dual logic and power control for 5-phase stepper motor
| January 1989
| 40V DC, 6A , 5x Siemens TCA1561 PWM power chips, interlaced chopped current (lower noise and smoother power consumption),
hand-drawn PCB layout, photographically reduced on high-contrast, transparent Lith film with clear base,
EPROM based stepper logic
(with hindsight, this is actually termed an FSM, finite-state-machine, built with an EPROM 2716 and an 6bit register),
manufacture of dual-side PCB by Bernhard Tritsch
| 14 years at FhG-ISE, powered the main drive motors at my photo-goniometer pg1
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| opto-coupler with TTL Schmitt-Trigger
| January 1989
| 4x 24V DC in
| 14 years at FhG-ISE
input signals at photo-goniometer pg1
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| photo interrupter with TTL Schmitt-Trigger
| January 1989
| 4x TTL_out
| 14 years at FhG-ISE
reference position sensors at photo-goniometer pg1
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| pab "quadro-serial" card QSC for Apple][
| April 1987
| 4x RS232,
offered more much-needed serial connections in a slot-limited Apple-2, which was used in an experiment at Fraunhofer ISE.
Hand-made PCB layout, manufacture of dual-side PCB by Bernhard Tritsch,
cold-contacts by Genswein GmbH, all Freiburg
| multiple years at FhG-ISE (Antonio Pflüger's "k-Wert")
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| DIY home-built kit with Motorola MC68000 CPU
| 1986
| The 68k project of German publication "ct" featured a wealth of improvements over the Apple][: More memory, higher floppy capacity,
graphic processor, "real" colour graphics, lots of soldering. My main use was writing a hidden-line algorithm in object space,
which allowed to record a short animation on Super-8 (camera was a Beaulieu providing nicely exact timing and control by the Apple][).
Programming language was the real-time Pearl,
which allowed two tasks running in parallel, hence the 3D line-drawing could be done with a client-server model.
| once-off testing animation
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| interfacing an IBM-XT keyboard to an Apple][ clone
| May 1986
| When the clone Apple-2 motherboard got "upgraded" to a complete system, the keyboard of the IBM XT was much nicer than an Apple keyboard.
My solution consisted of a second (non-Apple) 6502 board that solely interfaced the XT timing and key-map to the Apple interface.
Programming was done in 6502 assembler, burned into an 2716 EPROM.
| serial terminal to an MC68000 system
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| memory expansion of an Apple][
| summer 1985
| When cheap clones of Apple-2 motherboards became available, it was relatively easy to use a second, passive motherboard as
memory expansion to a classic Apple-2. The interface card was hand-wired, using 74LS373 transceivers and some logic.
Note missing EPROMs on the clone board.
| some months, until a larger MC68000 system became operational
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| interfacing an Apple][ to a mechanical SEL teletype
| around 1983
| A 5bit teletype, made by SEL, was interfaced to an Apple-2 without need for extra logic, using an NPN transistor to drive the solenoid.
Substituting the I/O routines of the Apple][ with suitable look-up tables and timing allowed the teletype to be used as a terminal, with
wires running diagonal through the flat. It provided a true /dev/tty to an Apple-2, if you want to put it that way.
| demo
| (images not yet located)
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