Doughtronics - Circuit Ideas.

Transcription

1 Doughtronics - Circuit Ideas Fall 2016 Rev. Page 1 of 13

2 To start, be sure you can get a single LED to light up. Try this, using 2 lumps of dough: The LED might not light up. If it doesn't, reverse how its wire are connected into the dough. Note above, the dark wire is to the left and below, it's to the right, like this: As you may know, LEDs are the new and efficient lighting technology, but they must be inserted into your circuit properly in order to work. Page 2 of 13

3 Try this with two LEDs both stuck into the same to lumps of dough. Remember, you might have to reverse the connections of one, or both LEDs to get them both to work. Here's a three lump circuit: Again, one LED inserted "backward" will cause both to not light up. Page 3 of 13

4 Here are some dough-style switches you can make: If you push the two lumps of dough together, the LED should go off. Pull them apart again, and it'll come back on again. Here's another switch. This time, touching the lumps A and B will cause the LED to go on. This is just opposite to the switch above. Page 4 of 13

5 Here's another type of switch that uses your finger to turn on an LED: The LED won't be that bright when it comes on, so be sure to do this is a dark place and look very closely into the LED. You can also build this circuit: Try putting miscellaneous objects in for the?-mark, like a coin, paperclip, metal spoon, nail, screw, piece of plastic, aluminum foil, etc. Can you tell what types of materials "conduct electricity?" This circuit is a "conductivity tester." Page 5 of 13

6 Find the LED that flashes. If you don't know which it is, try inserting all of them, one by one, into this circuit, remembering to reverse and LED if it doesn't come on at all. At some point, you should see it flashing, like this: This flashing LED can make other LEDs flash too, like this: You'll have to add a 3rd lump of dough. When it all works, both LEDs should now flash. If the flashing LED worked before you added the 3rd lump and red LED, and now it doesn't, you probably need to reverse the red LED's connections. Page 6 of 13

7 Try getting the beeper to work, like this: The beeper is like an LED---if it doesn't work, reverse its connections in the circuit. The flashing LED can make the beeper go on and off, like this: If the beeper is too quiet or makes a clicking sound, give it a tap with your finger, or knock it gently on the table, to help it get started. Page 7 of 13

8 Try using the push button switch to turn your circuits on and off, like this for the beeper: And this for an LED: In these circuits, the LED or beeper will go on when the switch is pushed down. See the next page for a variation of this... Page 8 of 13

9 In this circuit, the LED is on, and goes off when the button is pushed: If you're interested, this circuit, and those on the last page, are examples of a switch "in series" (last page) an "in parallel" (this page), with a circuit element (like an LED or beeper). Page 9 of 13

10 Here's a "smart" circuit that knows about how much light is coming in around it: When the LED is on, cover the photocell tightly with your thumb of finger, blocking all light from hitting it. Or, take the circuit into a very dark room. The LED should go off. Letting light hit the photocell, will turn the LED on again. If you send a lot of light onto the photocell, like using the light on your cell phone, and holding it right up to the photocell, the LED should glow brightly. This circuit is opposite to the one above, in that the LED goes off in you send a lot of light onto the photocell. Page 10 of 13

11 Here's a smart circuit that knows what orientation it's in. Find the black cylindrical element that makes a rattling sound when you shake it and build this circuit: Try holding the rattling element (called a "tilt switch") right side up and upside down. You can control the LED by its orientation. Try shaking the switch too, or replacing the LED with a beeper. Be sure your LED is inserted properly (you might have to reverse its connections), and works all by itself first. You can try swapping the LED for a beeper too. Page 11 of 13

12 Here's a smart circuit that knows when a magnet is nearby. Find the black cylindrical element that DOES NOT make a rattling sound when you shake it. Next, hold a magnet nearby. The LED should come on when the magnet is close. Try replacing the LED with a beeper too. In this circuit, the beeper will stay off while the magnet is nearby. Can you use this to make an alarm for your door, backpack, or desk drawer? Page 12 of 13

13 Here's a circuit called an "AND gate" in that the LED only comes on when the button is pushed AND the magnet is nearby. Computers contain millions of AND gates. Here's the same, but it's an OR gate. The LED comes on if either the push button is pushed, OR the magnet is nearby. Page 13 of 13