Simple electrical circuits

copper tape circuits

(1) When you fold the corner over and put the clamp on, the trace on the left will touch the top of the pill battery, and the trace under the battery touches the opposite side of the battery. If you look closely, the top of the battery has a "+" mark on it, meaning it's the positive side of the battery. Therefore the bottom is the negative, and it is connected to the short leg of the diode. When making this pattern, I cut the tape down the middle, this makes it easier to make curves, but you don't have to do that. You can get artistic here, and shape the traces into fancy curves. But keep the gap you see at the bottom.
(2) Fold over the corner and put the clip on, this connects the battery. I laid a piece of copper tape across the gap, and the LED turns on brightly, since an electrical current can run all around the circuit.
(3) Here the current runs through a resistor, which impedes the flow of the electrical current. As a result, the diode shines, but very weakly.
(4) First we measure the voltage of the battery by touching the traces that are connected to the top (left) and bottom (right). The meter is set to the DCV (DC Voltage) sector, and the scale is chosen to be 20 Volts max. The meter reads 3.1 Volts. Note the LED is not on, since nothing is bridging the gap at the bottom.
(5) Here we measure the current that runs through the circuit when the LED shines brightly. The meter is set to the DCA sector, which means Direct Current Amperes. The scale is chosen to be 20m, which means 20 milliAmperes max. [when you use the DCA setting, the meter offers (almost) no resistance to the current, so it acts like our little piece of copper.] The current reads -3.75 mA.
(6) If the current also has to go through the resistor, the flow is throttled to only -0.91 mA.
(7) Here we measure the resistance of the resistor in our circuit. The meter is set to the sector labeled $Ω$ (the Greek letter Omega), which stands for Ohms, the unit for electrical resistance.
(8) Let's have a closer look at the resistor. It has 4 colored bands, In our case, the bands are brown (1), black (0), red (×100), which means 10×100 = 1000 Ohms. The last band is gold, which means a tolerance of ±5%, and 1006 Ohms is well within 950-1050 range.
Here is where you can let your artistic side shine
You can use more than one LED. Note the polarity is labeled with + and − Experiment! - Multiple LEDs? - Different resistors in the circuit? - Paperclip switches?

Hubert van Hecke

Last modified: Tue Jun 15 17:47:23 MDT 2021