multiple mosfets on basic stamp

PLJack

www.al-williams.com/fetrly.htm

With the circuit listed above on each BS2 pin, can the stamp turn on 8 to 10 of these MOSFETs at the same time?
If so, how fast is the switching?


Thanks.
Jack

Dave Paton

How many? Until you run out of usable output pins. How fast? That depends entirely on how tight your code is, and how fast the FET is. If it has a lot of gate capacitance, it'll take a little while to charge, but I think it'll be faster than the Stamp is able to cycle the outputs unless you're using FETs with Cg measured in nF

-dave

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PLJack

Dave Paton said...
How many? Until you run out of usable output pins. How fast? That depends entirely on how tight your code is, and how fast the FET is.
-dave

Thanks for the reply Dave.

The Fets will be connected to 12v solenoids.
They need to fire within a few hundred milliseconds.
Sounds like it will work fine.

I was going to use relays, but I like the FET idea much better.

Jack

allanlane5

Yes, and you can turn on 8 all at the same time with the OUTH or OUTL command, if you've wired them to P0..P7 (OUTL), or P8..P15 (OUTH).

In any event, a few hundred milliseconds is a reasonable amount of time for a BS2. It cycles around 100 uSec per instruction. You could do 8 separate outs in around a millisecond.

PLJack

allanlane5 said...
Yes, and you can turn on 8 all at the same time with the OUTH or OUTL command

I had assumed that. Thanks for the confirmation.

allanlane5 said...
In any event, a few hundred milliseconds is a reasonable amount of time for a BS2. It cycles around 100 uSec per instruction. You could do 8 separate outs in around a millisecond.

And thanks for the 8 outs/pm info. The platform will be moving, I'll be using that information. [noparse]:)[/noparse]

Jack