[Making DAC with 0808]

can someone give me another shcematic of DAC????because when I use that schematic the output voltage always 4V...
in that schematic i change the resistor into 5.6 Mohm..

[Making DAC with 0808]

I've the same problem...I'm using the circuit in datasheet of DAC0808..
you can see the circuit in the pic...

[help!!!]

thanks for the reply.....
maybe this will help to understand that formula...
that formula was made in laplace...and  you can see their explanation...
does anybody know the relation between voltage and speed motor DC??
my argument :"bigger voltage will make the speed faster...but its speed change doesn't linear..."
is there any argument????

[help!!!]

hi...
I'm in final project and I've a problem...in this formula :
can somebody help me explain for every part of that formula...
especially "beta" and "J"

I want to know the formula of voltage to speed in motor DC...
can somebody help me to explain or give me the website about it...
thanks... 

[Datasheet Request]

haii....i'm a newbie...
can i get datasheet about "1525 analog compass"..
thx

[please help a newbie]

hi..I'm newbie...
can somebody tell me about estimation position??can I get web site about it??
thx