H
Howhurley
- Jan 1, 1970
- 0
I've got a situation I hope one of you wonderful circuit designers can
help me with. In a three wire (+24VDC, DC GND, and a 12-24 signal
from a PLC, perhaps 100 ms in length) I need to come up with a
monostable ramp signal from 0 to 10 volts, no more than 10-15 mA,
approximately 1 sec in duration, adjustable in slope.(gain)
Three thoughts I had were:
1. A simple RC circuit, (non-linear, I know, but buffered with a
cheap op-amp front and back to even things out)
2. A 555 timer/oscillator to charge a cap until it hit a certain
point on an op-amp comparator which discharged the cap...the voltage
level would then be tracked by a unity gain follower and actually be
my output.
3. A simple 8 bit d-a, charged by a oscillator circuit,
4. Of course, a simple rabbit or pic microcontroller...but that's for
the future.
Any ideas? I'm a sales guy that sells industrial stuff, and some of
the things I sell are ideas on how to do things. I quoted a job,
assuming that this type of thing was available, and, well, you know
about assuming things.
Howhurley
help me with. In a three wire (+24VDC, DC GND, and a 12-24 signal
from a PLC, perhaps 100 ms in length) I need to come up with a
monostable ramp signal from 0 to 10 volts, no more than 10-15 mA,
approximately 1 sec in duration, adjustable in slope.(gain)
Three thoughts I had were:
1. A simple RC circuit, (non-linear, I know, but buffered with a
cheap op-amp front and back to even things out)
2. A 555 timer/oscillator to charge a cap until it hit a certain
point on an op-amp comparator which discharged the cap...the voltage
level would then be tracked by a unity gain follower and actually be
my output.
3. A simple 8 bit d-a, charged by a oscillator circuit,
4. Of course, a simple rabbit or pic microcontroller...but that's for
the future.
Any ideas? I'm a sales guy that sells industrial stuff, and some of
the things I sell are ideas on how to do things. I quoted a job,
assuming that this type of thing was available, and, well, you know
about assuming things.
Howhurley