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[SIGMusic] circuit



i talked to a friend a little about the circuit we're making. 

he basically said it would work.  however...we run the risk of killing lots of circuit boards.  as well as the solenoids.  using a pic to provide power is basically bad design.  but whatever, we don't care.  and his question was can you even find a transister that will pull up..what is it?  15mA - 50mA (or 75mA)?  or .83V - 24V?  i am assuming we did find transisters. 

i'm not entirely sure that we need the volt regulator, unless we can't control the voltage output.  it's only amps, right that we can control. 

he suggested using flip flops (D).  and something about Darlington.  whatever. 

if i'm reading the specs correctly, the amps / volts out of a single pin changes depending on what pins are in use / or on.  that sucks ass and i hope i read that wrong. 

eh, i left my backpack in my friend's car, and i don't know when i'll get it back because of the weather.  i'm just gonna write down everything that we supposedly know.  

5 I/O ports
PortA : 6 input/output
PortB : 8 input/output
PortC : 8 input/output
PortD : 8 input/output
PortE : 3 input/output

Port A+B+E has a sink/source max of 200mA. 
Port C+D has a sink/source max of 200mA. 

each indidvidual pin has a sink/source max of 25mA. 

the pic needs 5V (high).  actually this can go to 5.5V, but..that would probably be risky as far as frying stuff goes. 

each pic will handle 2 instruments.

that's 11 solenoids and 1 solenoid valve controlled by 1 pic. 

all 12 outputs will each have a single transister. 

the solenoids need 24V / 50mA. 
the solenoid valves needs 24V/ 75mA

the TRISx register will denote whether a i/o pin is input or output.  this is done with the pic assembly and is part of the setup for the ports.  (TRISA for porta, and TRISB for portb...)

i'll draw a circuit diagram later.  it might be paper format, since i suck at drawing on the computer. 

i'll look at teh stupid diagrams, however, the graphs don't mean a whole lot to me.  i have a vague memory of "sharing" graph diagrams with former classmates. 

steph