Circuit Help

[RubberMan]

Can any body help me please?

I am trying to simulate certain conditions by using a chart recorder.

The chart recorder requires a low current, low voltage input to function correctly. (I believe its 0 -10 V DC)

I need a circuit that will produce a voltage that will fluctuate between 8 and 9 volts!

Is this impossible or is there someone clever out there that can help me?

Thanks in advance

 

[Nigel Goodwin]

Can any body help me please?

I am trying to simulate certain conditions by using a chart recorder.

The chart recorder requires a low current, low voltage input to function correctly. (I believe its 0 -10 V DC)

I need a circuit that will produce a voltage that will fluctuate between 8 and 9 volts!

Is this impossible or is there someone clever out there that can help me?

Thanks in advance

You don't much in the way of details?, but a simple potentiometer across a 12V supply should do the job - perhaps with a series resistor or two to limit the range of adjustment.

 

[mstechca]

Try an astable multivibrator. A transistor multivibrator can have two outputs. One output is the inverse of the other output.

One output (of the multivibrator) will enable an 8 volt source and at the same time, disable the 9 volt source. After x seconds (depending on resistors and capacitors in the multivibrator), the reverse is true.