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tatapoum

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Posts posted by tatapoum

  12. [blog] 4xSID photoblog

    in MIDIbox SID

    Posted

    That's a part of the challenge to know if an idea is good or not until the end.

    I think I will order some black caps... My initial idea was to have something like EMS VCS3. I admit the result is far away to what I expected. But Fisher Price are nice toys.

    I've ordered this button at a french online component shop, GoTronic.

    Button are 0,95 euro and caps 0,15. These button are available from 15mm diameter to 45mm. The catalog page is here (only in french).

    ludo

  15. Speakjet - A PIC ready sound chip?

    in MIDIbox User Projects

    Posted

    I'm about to finish the control application; just have to fix the recording buffer...

    now I'm wondering if I forgot something, that should definitely be part of a first release:

    Wow, that's amazing. I've receive a speakjet from HVW Technologies.

    I intend to use a little AZERTY keyboard and integrate it in a box. Do you thinkk that is something easily achievable in terms of software ? On the hardware side, I know it's not so complex. I aim to write the sentences to be spelled.

    Cheers,

    ludo

  19. PSU design

    in Design Concepts

    Posted

    cool, so you've built this design then?

    Yep.

    how quiet is it?

    The voltage oscillated at less than 10 mV. And the sound seems to have not too much buzz.

    can it be compared to the c64 psu?

    I never have a c64 PSU, so I can't compare.

    also, what was the point of having a separate output for the LCD backlight? sorry, i'm new to all this complicated stuff!  :-[

    Yes, that's complicated. It's an adjustable regulator LM317 fixed at 4,2V with the pot. It's the best system I found to power up the LCD backlight. It needs 460 mA, that's quite amazing, and a serial resistor of 5 ohms at 3 Watt is not the prefered solution because the pots allow to low the luminosity.

    ludo

  21. [blog] 4xSID photoblog

    in MIDIbox SID

    Posted

    Hi,

    Will your LED matrix design fit into the originally designed frontpanel designed by TK?

    It should. The diodes are on a 2/10" (5,08 mm) grid.

    i have one question.....in which sections are non-detended encoders....in which detended Encs better for handling ???

    i think menue encs detended....rest Non-det. .... Right ??

    You're right.

    ludo

  25. PSU design

    in Design Concepts

    Posted

    Thanks for your suggestion. However with your design, the 7812 is overload. The 4.2V used for the backlight consume 450mA and main 5V for logic and LED has a similar need.

    Moreover, I've read somewhere that cascading 78xx may produce a lot of noise. As 7812 provide current for SID module, this not, in my opinion, acceptable.

    My major concern is about the rectifiers. Two diodes are parallized and I feel that's not a 'clean' design. But it works even if they come hot.

    As I've said in my previous post, 12VAC if perfect to provide 12VDC. The rectifier drops the voltage to 17V (1,42 x 12, rectified current rules) and the voldate drop down of a 7812 rectifier is about 2V.

    ludo

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