Quote:
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Originally Posted by Groth
Your analog (power connector) and digital (p-port) ground: keep 'em separate. Star ground > ground loops. Same with the shunt inputs, don't tie it into board ground.
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Do you mean
totally seperate analog and digital grounds? i.e. connect only the DGND pin of the ADC only to the parallel port ground? No connection to the AGND pin or power supply ground at all? Anywhere? Should the Flipflop and the digital IO's be connected to P-port ground? but at the same time they need a power ground.
Or should there be a single connection for the digital circuitry as per the datasheet...
But they suggest a star ground.
Sorry, I get confused all the time about this.
PCB,
schematic.
Damn, back when I was supposed to know all this I was drunk. I do remember hating to manually insert little via rivets so I avoided them like the plague. It carries through still perhaps.
Hmm, so surface mount is easy eh? I'll have a look at that I think.
Been thinking about the PWM circuit. The comment about the time constant triggered a flurry of calculation which led to a bit of a tiff with the Differential Calculus. I came out of it OK I think. T@t=e^(-t/c*m*(C/W))*(DTi-((C/W)*W)+(C/W)*W is my thought for the day.
Anyway, this comparator fan control circuit is a PWM circuit in a way. The triangle wave generator is the water itself and the fan. Just a really low frequency and a bit of PFM as well.
A bit of friday night irrelevance.