Archive of the former Yahoo!Groups mailing list: ComputerVoltageSources

I may want one of these 16 analog input boards for my PSIM for a
sequencer so I designed an ExpressPCB mini-board. For those of you
that don't know, this is a fixed-size set of 3 quicks with no solder
mask or silk screen for $51. It makes small runs of PCBs pretty
affordable.

I put the design file "I2C Analog-Digital Design Files 4-10-07.pdf" in
the files section. I put 4 of the PCF8591 parts with 4 analog
channels per part for 16 inputs. There is no over/under voltage
protection as it is intended to directly interface to 16
potentiometers.

Andrew - I know you are trying to do something with 16 switches so I
added two MCB23008 parts for 16 digital inputs/outputs. Maybe this
will be easier than wiring up your parts.

Regulation is from +15 volts through a 78L05. There is very little
current draw from these parts so the L version should be sufficient.

I added two MTA power connectors so this board could daisy chain with
either the PSIM or LCD-Support PCB. I put an extra 3 pin MTA-spaced
set of holes so wires could be soldered directly to +5, +15 and
ground. Connection to a PSIM is through a two-wire interface to
connector J3.

I'll leave it up in the files section to take any feedback before I
order mine. I would appreciate if someone would give them a quick
look-over. I've used both of these parts on my AtomPro so I know they
work. I haven't used all 6 together but don't see any issues.

For PSIM owners who want a sequencer, I have a 16 step program on my
web page. It already interfaces to a single PCF8591 so it wouldn't be
hard to modify. I use the eeprom in the AtomPro28 so that would have
to be modifed although you could replace the AtomPro24 with a
AtomPro28 to get the non-volatile storage (That's what I did with my
PSIM). If you add John's LCD Support module then you'll also get MIDI
and a display for a user interface. Connection to the PSIM is through
a three wire interface to connector J5. I have videos of my sequencer
LCD also on my website.

Disclaimer - I don't sell boards and I'm not in that business. I have
previously made parts available like my A440 generator and the LCD
Support module with John only to have email interest go unanswered
after buying parts. I will put the design files up for anyone who
wants to order some after I have verified functionality. Maybe two or
three of you can get together to pool a single order. The ICs are very
inexpensive so it would be quite affordable.

Dave