Potentiometer changes not noticeable

[BJH1984]

Hi,

As part of an activity we are having students hook up an LED number readout on a protoboard that is controlled by a potentometer. So as you adjust the potentiometer the speed that the readout counts from 0-9 changes. Before they physically build the circuit we are having them look at a simulation in Multisim. However, when I run the simulation and adjust the slider on the potentiometer there is not a noticeable change in the speed the readout counts. Any ideas of what I need to change to make it more obvious? I attached the file we are using. Any info would be very helpful since i'm not too familiar with Multisim or building circuits for that matter.

[mnauss]

Why not just increase the frequency of your clock generator (LM555). You can decrease the value of C1 to acomplish this. Something like 1 uf should be good.

[ahillinaustin]

Hi  BJH1984,

Thanks for posting on the discussion forums with your Multisim question! I tested your code and saw the same behavior your were seeing. Just as mnauss was saying, the quickest fix (at least in Multisim, maybe not in the real world) is to change C1 to a smaller capacitance, somewhere in the range of 1-5 uF. At about 2.5, I was able to see a gradual but noticeable difference in the frequency of the counter. Hope this helps!