16-03-2017, 09:20 AM
Hi Mark,
You're following the same line of reasoning as me regarding the 'A' line. You'll notice that R802 is referenced to ground, so it would reason that the A line is an input to the micro, however when I lift the inter-board connection for A, the micro side stays solid at about 16V, whereas the voltage on R802 falls to zero, only coming up to ~15v when Time ADJ and one of the buttons assosciated with Q801 is pressed.
The 3 contact switches are odd, they threw me for a while, before I had the diagram I was wondering why I seemed to get 3 different voltage readings on the same set of contacts!
I've looked for pulses and found none, this whole thing works on logic 1/0, just at unconventional voltages.
It's time is short....
You're following the same line of reasoning as me regarding the 'A' line. You'll notice that R802 is referenced to ground, so it would reason that the A line is an input to the micro, however when I lift the inter-board connection for A, the micro side stays solid at about 16V, whereas the voltage on R802 falls to zero, only coming up to ~15v when Time ADJ and one of the buttons assosciated with Q801 is pressed.
The 3 contact switches are odd, they threw me for a while, before I had the diagram I was wondering why I seemed to get 3 different voltage readings on the same set of contacts!
I've looked for pulses and found none, this whole thing works on logic 1/0, just at unconventional voltages.
It's time is short....
