Circuit 1: Single Light

Building Electrical Circuits Circuit 1: Single Light

Okay, now it is time to build a circuit. We are going to wire the battery directly to a single bulb. This is a good test to make sure everything is working well!

This circuit looks like:

Follow the video below to build this circuit on your own workbench.

video

Understanding This Circuit

Try these steps to more deeply understand how your circuit works:

With your finger, trace the path of the electricity starting from the battery and returning to the battery.
Using the multimeter:
1. Check the voltage from the battery to establish your supply voltage.
2. Determine the resistance of the bulb in the socket.
3. Determine the resistance of the bulb out of the socket.
4. Which is higher? Why would this be?
5. Check continuity across the socket with the bulb installed. [SHOW HOW THIS IS DONE.]
Take the bulb out of the socket and disconnect the battery leads from the socket terminals.
1. Holding the bulb in your hand, touch one battery lead to the base of the bulb and the other to the bottom terminal of the bulb, but don’t let them touch each other.
2. Keep trying until the bulb lights up.
3. Touch the black ring around the bottom terminal with the battery lead; does the bulb light up?

Feel like you've got this circuit mastered? Move to the next page and let's build another one.

Troubleshooting

No? Let’s troubleshoot it.

Make sure the On-Off switch on your battery case is ON. Did that make the light come on?

Let’s troubleshoot some more. Here are some things you can try.

Remove the lightbulb and insert it again, seating it gently but firmly in the socket.
Try the other lightbulb.
Check your batteries for charge: set the multimeter to 20V on the DC settings and put one probe on each of the leads coming from the battery holder. You should get about 3V. If you do, the batteries and battery holder are good. If not, try new batteries. Make sure to put them into the holder pointing the right direction.
Take the bulb out of the socket and disconnect the battery leads from the terminals on the socket. Hold the end of one battery lead to the threaded base of the bulb and the end of the other lead to the bottom terminal, but don’t let the battery leads touch each other. If the bulb lights here, you either have bad connections to the socket or the socket is bad.
Check the leads between the battery case and the socket to make sure there is good metal-to-metal contact with the screws in the thumbnuts. If these look good, you might have a bad socket.
Check your socket for continuity. DISCONNECT ONE OF THE LEADS FROM YOUR BATTERY HOLDER. Set your multimeter on the buzzer setting and touch the probes together. If it buzzes, you are ready to test. Touch one probe to the metal part of each terminal on the socket. If it buzzes, the socket is good.

If nothing works, call your guide for what to try next.

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