Jump to content

How "optional" are these BC547's on T2-T9 of the MB-6582?


dubka

Recommended Posts

If you don't solder them in, you would need to put jumpers in their place.  They are "current sinking" transistors.  If you opt out of them, you might be OK if you don't use bright LEDs, but if they draw too much current you will destroy a shift register IC.

If you have them, there is no disadvantage to using them.

Link to comment
Share on other sites

They are not really optional. The firmware expects them there (it inverts the outputs so that a high DOUT pin causes current sinking). You would need to modify the source code to not invert the outputs. Not really worth the effort, since they're there to sink more current than the shift register can handle by itself... i.e. sinking current from 16 LEDs.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...