Time vs voltage circuit

[[email protected]]

I need help in order to make a circuit which will do the following:
Measure the time a voltage is applied (or switch is closed) and
convert the time to an output voltage (linearly). Also measure the
time when another switch is closed (or voltage applied in another
circuit) and linearly convert this time to REDUCE the same output
voltage. Is there an expert out there who can give me advice on how-
to?

Thanks
Lars

 

[D from BC]

I need help in order to make a circuit which will do the following:
Measure the time a voltage is applied (or switch is closed) and
convert the time to an output voltage (linearly). Also measure the
time when another switch is closed (or voltage applied in another
circuit) and linearly convert this time to REDUCE the same output
voltage. Is there an expert out there who can give me advice on how-
to?

Thanks
Lars

How about...
Use a constant I source on a cap for increasing V with t.
Use a constant I sink on the same cap for decreasing V with t.

D from BC

 

[[email protected]]

I need help in order to make a circuit which will do the following:
Measure the time a voltage is applied (or switch is closed) and
convert the time to an output voltage (linearly). Also measure the
time when another switch is closed (or voltage applied in another
circuit) and linearly convert this time to REDUCE the same output
voltage. Is there an expert out there who can give me advice on how-
to?

Over what sort of period? There are well-established techniques
embodied in off-the-shelf time-to-voltage converters for microsecond
to nanosecond time scales.

If the times involved are in the seconds to milliseconds range, a dumb
microcontroller is a much cheaper solution.

 

[MooseFET]

How about...
Use a constant I source on a cap for increasing V with t.
Use a constant I sink on the same cap for decreasing V with t.

A gear motor and a 10 turn pot.

 

[Don Lancaster]

I need help in order to make a circuit which will do the following:
Measure the time a voltage is applied (or switch is closed) and
convert the time to an output voltage (linearly). Also measure the
time when another switch is closed (or voltage applied in another
circuit) and linearly convert this time to REDUCE the same output
voltage. Is there an expert out there who can give me advice on how-
to?

Thanks
Lars

A PIC, of course.

--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[[email protected]]

I need help in order to make a circuit which will do the following:
Measure the time a voltage is applied (or switch is closed) and
convert the time to an output voltage (linearly). Also measure the
time when another switch is closed (or voltage applied in another
circuit) and linearly convert this time to REDUCE the same output
voltage. Is there an expert out there who can give me advice on how-
to?

digital up-down counter with an R network on the output's doing the DA?