Contemplations Upon Voltage As Visualized As The Height Of A River


I’ve never been comfortable with my understanding of Voltage. This post is me trying to get it straight in my mind by thinking “out loud”…

My touchstone is the equation I have been handed down as the electronic gospel:

Voltage = Current * Resistance      (aka:   V = C * R )

Which is to say, if Current increases, then Voltage increases also, assuming Resistance doesn’t go down.  And if Current doesn’t go down, but Resistance increases, then Voltage will also increase. Similar goes for decrease situations.

Can I not then think of Voltage as a dam, and Current as a river? A higher Voltage would then be visualized as a higher dam. No, no–

No, the Resistance is the dam. The Voltage would be… Voltage would be the height of the river (and the increasing pressure associated with the increasing height). Yes… The dam (Resistance) impedes the river (Current). The river does not stop moving when it strikes the dam, of course. Instead, more waters (electrons) keep flowing in, and the river begins to rise up the dam (Voltage increases). When the river is high enough (when the Voltage is powerful enough) the river will flow over the dam (the Current will move through the Resistance).

The height of the river (Voltage) will be maintained at the level which allows the river (Current) to continue flowing past the dam (Resistance). The height of the river will not need to increase more to keep flowing, and the height cannot be reduced, or else it would not continue past the dam (the circuit would be broken).  Or…if the height of the river at the dam WERE to be reduced, it would start building back up toward the height necessary to again traverse the dam.

Another scenario:  If the Current is assumed to remain constant, then if the dam (Resistance) is lowered, the river ‘s height will lower also (the Voltage will lower)– just staying high enough over the dam to continue passing at the same rate. This satisfies the equation V = C x R mentioned above.

If the Current is allowed to flow correspondingly harder as the dam (Resistance) is lowered, then the river will maintain its height, and more water will flow over the dam. Thus, the Voltage (river height) will remain the same even as the Current increases and the Resistance lowers. This also satisfies the equation V = C x R.

On the other hand, If the height of the dam (Resistance) is raised, then either the Current will be reduced or else the height of the river (Voltage) will need to increase in order to maintain the same Current. This also satisfies V = C x R.

If I’m right or close to right, then I may be starting to “get” the distinction between “volts” and “amps.”  If I’m very wrong, then pretty much all hope is lost of me ever understanding Voltage.


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