A
Anonymous
Guest
Same post as on Geotech, got busy & forgot to post it here...
<HR>
Here is the first draft of a new PC board I've worked up, this time using surface mount devices. It's 2 x 2.3 inches, a little less than 1/3rd the area of the old board.
The major ICs and most discretes are SMD, using SOIC and 0805 sizes. Having hand-soldered down to 0402, I think 0805 is as small as most hobbyists can deal with. I kept the 78xx regulators in TO92 because SMD doesn't save any space. I kept the electrolytics through-hole as well, and the trimmer pots, for easier availability.
This version of the design eliminates most of the "options" of before. The preamp will have a single method of offset tweaking, which should still work for most opamps. The option of VCO and non-VCO is maintained. One nice thing, is that all the I/O's and pots are around the edge of the board.
Feedback is welcomed...
<IMG SRC="http://www.thunting.com/geotech/forum/tech/images/top300.jpg">
Top layer. IC placement is basically the same as before.
<IMG SRC="http://www.thunting.com/geotech/forum/tech/images/bottom300.jpg"></P>
Bottom layer. Most of it is ground plane, wide runs are supplies. 3 SMD resistors and 2 big honkin' caps go on this side.
<HR>
Here is the first draft of a new PC board I've worked up, this time using surface mount devices. It's 2 x 2.3 inches, a little less than 1/3rd the area of the old board.
The major ICs and most discretes are SMD, using SOIC and 0805 sizes. Having hand-soldered down to 0402, I think 0805 is as small as most hobbyists can deal with. I kept the 78xx regulators in TO92 because SMD doesn't save any space. I kept the electrolytics through-hole as well, and the trimmer pots, for easier availability.
This version of the design eliminates most of the "options" of before. The preamp will have a single method of offset tweaking, which should still work for most opamps. The option of VCO and non-VCO is maintained. One nice thing, is that all the I/O's and pots are around the edge of the board.
Feedback is welcomed...
<IMG SRC="http://www.thunting.com/geotech/forum/tech/images/top300.jpg">
Top layer. IC placement is basically the same as before.
<IMG SRC="http://www.thunting.com/geotech/forum/tech/images/bottom300.jpg"></P>
Bottom layer. Most of it is ground plane, wide runs are supplies. 3 SMD resistors and 2 big honkin' caps go on this side.