Assembling a Circuit

1. Assembling a Circuit While Making A Dragonfly

2. With... • 2 LEDs • 2 Transistors 1 Resistor 1 Capacitor • 1 9V Battery • 1 Battery Clip • 9 Electric Wire Connectors Pairs • 8 Electrical Wires • 3 Jumper Wires • 4 Zip-ties

3. Now let’s move into the components…. Let’s start with the basic Concepts of Circuits • Voltage (V) • Is the difference in charge between two points • This comes from the 9V battery supply we are using today • Current (I) • Is the rate of which charge is flowing through a circuit • Resistance (R) • Is a material’s (or multiple materials’) ability to resist the flow of charge Electrical and Electronics Engineers use this formula to createbalanced and stable circuits. Voltage (V) = Current (I) x Resistance (R)

4. Light Emitting Diodes (LEDs) • LEDs are two-lead components that work in one direction. • This means that one lead is positive (called an anode) while the other is negative (called the cathode). • The negative side is the flat side of the brim. • LEDs emit light, when an appropriate voltage (called a turn on voltage) is applied. • The 2 LEDs will be used as your dragonfly’s eyes!

5. Transistors • Transistors have three leads and are used to amplify or switch (to turn on and off) electronic signals and electrical power. • The 2 transistors amplify the voltage in your circuit!

6. Resistors • Resistors are two-lead components, that reduce current flow • Direction is not a concern • The resistor in your circuit keeps your LEDs from burning up!

7. Last but not least, Capacitors • Capacitors are two-lead components, that store charge (like a tiny battery) • Direction does matter! • In your circuit the capacitor will allow the LEDs to dim off instead of immediately turning off. • A bigger capacitor (than what we are using today) would let the LEDs stay on longer before dimming out

8. Now let’s Build YOUR DRAGONFLY!!! • Use your connectors to construct your • Dragonfly's right wing • Fix pieces of wire in stubs 4, 6 and 7. (Start counting from where the eyes will be mounted) • Dragonfly's left wing • Fix pieces of wire in stubs 4, 5 and 6

9. Building YOUR DRAGONFLY • Fix the (2) 3 single connector stubs on the tips of the wires • Bind the loose connectors together with Zip-ties. • Pull the Zip-ties as tightly as possible.

10. Building YOUR DRAGONFLY • The Left Eye • Fix the LED’s negative-lead into the left side of connector number two. • Let the positive-lead run along the front side of the connectors.

11. Building YOUR DRAGONFLY • The Right Eye • Fix the other LED’s positive-lead into the right side of the first connector. • Let the negative-lead run along the front side of the connectors. • Connect both eyes across the front side of the Dragonfly's body. • Twist them together carefully with small pliers.

12. Building YOUR DRAGONFLY • Mount a battery  to the lower part of the dragonfly's back end. Use two Zip-ties to fix the battery. • Our body has 1 terminal pair shorter, but no worries the dragonflies will still look cute!

13. Building YOUR DRAGONFLY • To get the power from the battery to the dragonfly, you need to use a battery clip. • Fix the battery clips red lead into the eighth connector stub, on the right side of the body. • Fix the black lead in the seventh connector stub, on the left side of the body. • Don't connect the battery to the clip yet! *** You will end up frying your parts *** • Connect stubs 2 and 4 on the right side with a piece of jumper wire.

14. Building YOUR DRAGONFLY • Twist together one lead of a 10k Ohm resistor with a longish piece of jumper wire (with your fingers)!

15. Building YOUR DRAGONFLY • Fix the wire with the resistor into the first connector-stub, on the left side. • Fix the jumper wires' free end into stub number 8, also on the left side. • The resistor is now fixed with one tip. The other tip sticks out, like a dragonfly's antenna.

16. Building YOUR DRAGONFLY • Fix the other ending of the wire into connector stub number 5, on the right side of the body. • This is the second antenna. Bend it forward, across the Dragonfly's head.

17. Building YOUR DRAGONFLY • On the tip of each wing, a transistor is needed. But... be careful! The transistors must be mounted in the right way or your dragonfly won't turn on properly • The left and right wing transistors point the same way! • Let your instructor tell you which way the flat side points. • (one room points up the other points down) • Then connect the three leads into the three connector stubs for both sides.

18. FINALLY the LEGs • Find 2 free connector stubs connect the electrical wire at the 9th position on the body and attach 2 small connectors (as the feet)

19. Now its time to Test your Dragonfly(without the capacitor) • When you connect the battery to the battery clip and touch both antennas together, the LEDs should light up!Just like when turning on a light switch. • If not, don't panic! Just unplug the battery and raise your hand so we can troubleshoot it! • First, check the transistors! • Check the LEDs! Did you connect them in the right way to each other and into the connectors? • Check all the wires. Are they fixed into the right connectors? • Check the connections, esp. with the transistors. Sometimes the small leads escape from the screw's pressure.

20. Now Let’s Add the capacitor…. • But first do you see how the LEDs immediately turned off. • Now let’s unplug the battery and add the capacitor! • The positive side goes on the 5th spot (side with the longer lead) • The negative side goes on the 6th spot (has the grey strip)

21. Now let’s turn it back on • Connect the battery clip to the battery and touch the two antennas together • The LEDs will light up and when you break the antennas connection by opening the circuit you will see that the LEDs will dim off.

22. Congratulations you Completed this Circuit!!!