MisterBill2
- Joined Jan 23, 2018
- 18,477
It is not that there are wrong connections, but that there is room for improvement in a number of places. Of course I have designed a lot of boards over the years and experience is very useful.Hello MisterBill2, PrairieMystic, Bernard and the AAC forum,
Thanks guys. I got it to work.
Prairie Mystic,
Thanks for looking at the circuit logic of the schematic versus the
PCB diagram. I checked that several times but sometimes the logical
non sequitur made in the initial evaluation is also made in checking
the work.
MisterBill2,
The tip on diagnostic process sequence was the difference maker.
Using the DMM, the PIR V+ and ground were checked for nine volt potential.
Nope. So went back to the barrel jack.
A different wall wart was used for the PCB than the breadboard.
Once again its a simple thing that trips me up.
The polarity on the wall warts were reversed.
View attachment 204826
Not sure what this refers to but perhaps in the drawing PIR Sensor to 555
to LEDs (P5L), above, that the pads above and below J1 should be
eliminated and the trace coming from the cathode of the LED
should go straight to the T2 emitter. Or, extending this idea, the trace going to the
LED cathode should be bifurcated before it gets to the LED cathode
with one side of the fork going to the LED cathode and the other
side of the fork going to the T2 emitter. This would provide
a more direct, less serial, connection to the transistor.
Is that what is meant by 'less of a serial connection'?
If so, are there other instances?
(If this is correct will update the PCB design and repost.)
Thanks.
Allen in Dallas
PS Have reordered the PCB as a three-level board which
will further miniaturize the layout. Will follow up when
that one is loaded up.
And following a diagnostic procedure based on system function is the way to make money on fixed price servicing. So I can share what I learned over a bunch of tears on that aspect.
And I am relieved that no parts were damaged by the reversed polarity.