80C552 board


New toy – a Philips PCB80C552-5-16WP based single board computer.

The board is designed to have 64KBytes of EEPROM from 0×0000 to 0xFFFF, 32KB of SRAM from 0×0000 to 0x7FFF and 32KB of peripherals space from 0×8000 to 0xFFFF

On the same board I’ve placed a SPI RTC, EEPROM and 4.096 voltage reference for the on-chip ADC.

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Category: Electronica, Proiecte

New toy

Just got a new toy, to start working on some interesting projects: an HP3466A almost my age, but still kicking

Here are some pictures:

Related Images:

Category: Electronica | Tags:

Chinese PSU fix


This is a quick teardown and fix of a Chinese variable power supply.
While trying to measure a negative power supply I’ve discovered that the negative terminal was shorted to main’s earth and case


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Category: Electronica | Tags: , , ,

Notebook restoration


In this post i’ll show a quick walk-trough on how I managed to re-use an old Asus A6RP that had a sad ending.
In a few words, the entire case got smashed to plastic splinters. Luckily the internal components survived.
The case was rebuilt around two 4mm transparent acrylic sheets and 2.5mm pcb stand-offs, 10 and 15mm tall.

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Category: Electronica | Tags: , ,

RGB led lighting module update

top layer

This is an update for the led lighting project.
The design in complete and the PCB’s are almost ready.
This is the schematic:

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RGB led lighting module


I’ve started a new project: a RGB led lighting module, that can be controlled from a central communication node.

I’ll be using some SMD rgb leds, in 5050 case, that i ¬†got from e-bay.

The Imax is specified to 40mA, but i’ll be running them at 30mA max, to keep the heat down.

The design features are :

  • 50x50mm per module
  • cheap controller, JTAG interface, enough cpu power for high resolution/ speed PWM
  • the ability to run stand-alone, following a pre-programmed sequence
  • RS485 line drivers
  • wide input voltage range

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Ceas cu afisaj VFD

Ca o prima postare am ales un proiect mai “aratos”: un ceas cu afisaj VFD

Pentru afisaj am folosit un tub IV-18:

IV-18 tube

IV-18 tube

Caracteristicile tubului sunt:

  • 9 digiti, 8 cu 7 segmente si virgula, 1 cu simboluri speciale.
  • tensiune de filament : 5V la 85mA
  • tensiune anodica: 20-30V
  • curent de grila: 11mA per digit
  • curent anodic: 8mA per digit, cu toti anozii aprinsi

Mai multe informatii puteti gasi aici
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Category: Proiecte | Tags: , , ,