Make Electronics

Experiencing Electricity 21

Experiment 4: Varying the Voltage

6v Battery Pack

Volts

Figure 1-56. The meter shows how much voltage the LED takes.

6v Battery Pack

Volts

Figure 1-57. The meter shows how much voltage the potentiometer

takes.

Checking the Flow

Now I want you to make a different measurement. I want you to measure the
flow, or current, in the circuit, using your meter set to mA (milliamps). Remem-
ber, to measure current:

• You can only measure current when it passes through the meter.


• You have to insert your meter into the circuit.


• Too much current will blow the fuse inside your meter.

Make sure you set your meter to measure mA, not volts, before you try this.
Some meters require you to move one of your leads to a different socket on
the meter, to measure mA. See Figures 1-58 through 1-61.