some time ago kind mr CJ Miller sent me some old EFM schematics to upload them to my site. one was the
ADC flash, based on LED driver ICs (LM3915). i thought about the use for a ADC module for a modular
synthesizer and came up with the idea of controlling the steps of a sequencer with it. but why use expensive
or hard to get LM3914/15?
so i utilized an ADC0801 (or even 0804) for that purpose. this IC accepts 0V-5V input,
so i put a simple manual CV processor in front, with two additional comparators to drive helpful indicator LEDs for voltages
higher +5V or less than 0V.
the parallel output of the ADC gets converted to grey code and amplified to drive CMOS4016 switches. these switches
turn on/off the outputs of a 4017. BTW each control input of the CMOS switches can manually switched between
ON/OFF/ADC output to provide manual control of each step and to overwrite the ADC if necessary.
the actual sequencer section is a baby10, limited to 8 steps. the incoming clock gets ANDed with the sequencers
steps out to provide a trigger output, which pulse width follows the incoming clock.
here's the proto, side by side with the simple inverted divider proto. for the prototype i had only red LEDs on hand - will have to replace them later...