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Old 22 May 2014, 01:43   #414
robinsonb5
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Join Date: Mar 2012
Location: Norfolk, UK
Posts: 564
Quote:
Originally Posted by Johan1973 View Post
If it is an active low on the step, why not use a BC557 (PNP) BJT instead?
The complication with that idea is that the Amiga's Step pin is open collector and the ┬ÁC in the Gotek only pulls it up to around 3v.

Quote:
(EDIT: And to be on the SAFE side, wire that buzzer to +5V, it makes little difference to sound volume, but it makes a huge difference if the transistor breaks down and you send the buzzer voltage directly to the step pin.)
True - added to which the mod will then work even in external drive enclosures that omit the +12v wiring from their power plug.
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