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* With the DC voltage setting on the multimeter in the appropriate range, identify which is the positive and which is the negative wire coming from the adapter. The voltage setting on the multimeter dial is shown below. The number at top will display the current voltage. It is helpful to use a red and black alligator cable to connect from the multimeter probes to the power supply. Attach them as shown. WARNING: You need to plug the adapter into the wall. Be sure that you do not touch the two power supply wires together, this will short out your power supply and you will be out $5.00. This is your first live voltage!
[[Image:Voltage_setting.jpg | 300 px]] [[Image:Pos_neg_alligator_clips.jpg | 400 px]] [[Image:Testing_powersupply_voltage.jpg | 400 px]]
* Which is the positive wire and which is the negative wire? ** Is the positive wire labelled in any way? ** Attach a the red alligator cable to the positive wire, and a the black alligator cable to the negative wire. This is the standard color code for positive and negative wire, red for "+" and black for "-". We will use this throughout the course.* Unplug the power supply.
* Using one red and one black alligator cable and a short length of red and black hookup wire, connect the positive and negative lines from the power supply to the appropriate power buses on the breadboard.
[[Image:Power_connected.jpg | 400 px]]
* Plug the power supply back in.
* Measure the voltage across the positive and negative power bus. What is the voltage that you see? Is it the same at every point on the board?
* Unplug your power adapter from the wall, and look at the label on the back. What is the labeled output value?