Experiments PC1-PC73 manual: The manual revision is indicated on the bottom right of the cover.Rev B:(There is no revision A.)Note on using Winscope with Windows 7: be sure the cable is plugged into microphone port or youwill not be able to activate the Winscope on-line button. You may need to close Winscope and re-startit.Project PC1 – In the lower left illustration, the arrow from the text "Variable setting" should point to the"T" control, not the "Y1" control.Project PC15 – In last sentence, the microphone project is PC14, not PC5.(no Rev):Page 1 – The note to Mac users is incorrect, there is no Mac compatible software available at thistime.Page 4, Note A – pages 9-11 should be 8-10 and page 3 should be 4.Project PC1 – This circuit does not always work, change D2 to C3 (+ on left) to fix.Project PC10 – In the last paragraph, the Light and Sounds project is PC4 and on page 16.Project PC11 – In the last paragraph, the Microphone project is PC14.Project PC24 – This circuit does not always work. Remove C3, replace WC with C1, and place L2 inparallel with SP to fix (project 265 in the Rev-F Experiments 102-305 manual shows the revised cir-cuit). Project PC25 – If the circuit does not make any sound, then replace R2 with L2. Project PC34 – The circuit works better if you replace R5 with R4.Project PC52 – You are placing C5 on top of C4, not C3.

Experiments 512-692 manual: [The manual revision is indicated on the bottom right of the cover. SC-750 Changes to Rev C:Screw-in bulb/socket may have been replaced with a single-piece lamp.Project 590: Remove the circuit branch with S2, and remove all references to S2 in the text.Project 594: Set the meter (M2) to the LOW scale.Projects 641-644: See the next revision for improved circuits. Project 652: Remove the first and last sentences.Project 682: The case for the T1 transformer was changed, and the new case does fit. Use this re-drawn circuit:

Project 683: The case for the T1 transformer was changed, and the new case does fit. Use this re-drawn circuit:

B

A

A

B

Rev B: (There is no revision A.) Project 536 – Ignore the last paragraph of the text; it refers to a circuit that is not in your manual.Project 542 – Ignore the last paragraph, since resistor R1 limits the current.Project 549 – Red LED D1 should be under the blue snaps. Project 568 – The 1-snap at C5 is on level 1, not level 2. Project 595 – The 3-snap at C6 should be under capacitor C5. Project 601 – Do not place the fan on the motor.Project 613: Uses three 4-snaps but you only have two. Replace the 4-snap at D6-G6 with the redjumper wire; this also removes three 1-snaps. Project 615 – This project uses seven 1-snaps, but only six are available. The 1-snap at E6 on level 4may be omitted. Project 673 – Use the 6V lamp (L2) instead of the 2.5V lamp (L1). Project 674 – Use the 6V lamp (L2) instead of the 2.5V lamp (L1).Project 677 – Remove “(using a spacer on point B)”.Project 692 – If the lamp never turns on then replace resistor R2 with resistor R1.(no Rev): Page 3 – Remove “don’t” from last sentence of 3rd paragraph.Project 520 – The part beneath the press switch is transistor Q1.Project 523 – R4 is on level 2, not level 1.Project 526 - If the motor does not spin then give it a push with your finger to start it or remove thefan.Project 538 – The text was revised in Rev-B to be simpler. Project 550 - The green LED is dim even in sunlight. See Rev-B for revised circuit.Project 558 – There should be a jumper wire connecting point A on the alarm IC (below the 4-snap) topoint B.Project 577 – This circuit does not work very well. See Rev-B for revised circuit.Project 581 – This circuit uses U1, not U2.Project 584 – The text should refer to U4, not U2.Project 592 – Remove the 2-snap at E5-E6.Project 605 - Some text references to segment E should be C and some to segment C should be E.Project 606 – Rev-B has a revised circuit.Project 607 – There is no 1-snap at base grid locations B6 or E6. Projects 607, 608, 610, 612-615, 632, 640, 650, 651 – Note that some wires cross directly above oneanother with little separation but are not connected, this wiring arrangement gives the mistaken im-pression that these points are connected. For example, the red and black jumper wires are connectedto the 7-segment LED display but not connected to the 3-snap wires directly above them. These cir-cuit drawings were revised in Rev-B.Project 619 – This circuit may damage L1. See Rev-B for a revised circuit. Project 620 – This circuit may damage L1. See Rev-B for a revised circuit. Project 621 – Remove RP and shift S2 to RP’s location.Project 681– remove the 3rd paragraph of text.

Experiments 306-511 manual: The manual revision is indicated on the bottom right of the cover. Rev C: Screw-in bulb/socket may have been replaced with a single-piece lamp.Page 3, Project 308, and Project 312: Recording time for U6 is about 4 seconds, not 8 seconds. Project 307: Add a 2-snap across base grid locations D5-D6, on level 3. In some cases this will im-prove your radio reception. Project 317: Note that half of the 3-snap across base grid locations D1-D3 is under R4. This circuitmay be improved by placing the R1 resistor directly over the D3 diode using a 1-snap. C5 should beshown with the “+” on the right side (so the “+” gets the higher voltage), but this does not affect per-formance. Project 383: This was replaced with a more exciting circuit in the latest revision. Project 457: This was replaced with a more exciting circuit in the latest revision. Project 458: C2 should be below C1 in the drawing. Project 492: All references to “speaker” should be “whistle chip”. Rev B: Project 306 – Set the control lever on the adjustable resistor (RV) toward the left when you start.Project 343: S1 should be under the 2-snaps.Project 458 – Base grid location D1 should be labeled as point A, not point D.Rev A: Project 306 – This circuit does not work very well. See Rev-B for revised circuit.Project 307 – Remove first paragraph of text. Project 312 – D3 does not fit properly on U6. You can make it fit properly by replacing the 4-snap withthree 2-snaps.Project 317 – This circuit does not work very well. See Rev-B for revised circuit.Project 318 – This circuit may damage the SCR so replace the 3-snap wire with the 1K resistor (R2).Project 323 – This circuit is a 3mA meter, not a 1mA meter.Project 342 – The text should say 7 seconds, not 10 seconds.Project 343 – In the text, R4 should be R2.Project 358 – The text mentions current paths shown by arrows in the drawing, which are not in thedrawing. There should be an arrow in the upper-left part of the circuit showing a clockwise current,and an arrow in the lower-left part of the circuit showing a counter-clockwise current.Project 383 – Use the circuit from project 382, not project 381.Project 384 – Modify the circuit to add resistor R1 in series with LED D1, or D1 may be damaged.Projects 386 and 387 – Rev-B has a better explanation of how these circuits work.Project 393 – You hear the machine gun when the room is bright, not dark.Project 422 – You are replacing the 100µF capacitor with the 10µF capacitor.Project 434 – The text should say 15 seconds, not 10 seconds.Projects 440-443 – These are the same as projects 411-418, see Rev-B for revised circuits.Project 466 – The text mentions current paths shown by arrows in the drawing, which are not in thedrawing. There should be an arrow in the upper-left part of the circuit showing a counter-clockwisecurrent, and an arrow in the lower-left part of the circuit showing a clockwise current.Project 476 – Number 0 will be displayed, not number 4.Project 492 – The text should say to clap your hands next to the whistle chip, not the speaker.

(no Rev): On page 4, “the circuit.” should be added at the end of the description of the 7-segment LED display.Project 307 - Ignore the first paragraph. Project 312 - D3 does not fit properly on U6, you may let this part hang loose on one side and makethe connection with a jumper wire. Project 318 - Replace 3-snap with 1K resistor.Project 325 – In last paragraph, replace “/” with “part”. Project 338 – Add segment B, remove segment D. Project 339 – Add segment B.Project 340 – After “across points A & B” add “(use a jumper wire to complete the connection)”.Project 343 - Change resistor from 10K to 1K. Project 346 – The text is incorrect, it should say 1K (R2) and “increasing the resistance decreases”. Projects 347 & 399 are the same, this will be corrected when we revise this manual. Project 354 - Uses six 3-snaps but only 4 are available, use the snap jumpers as substitutes. Line 3of the text should say C3, not C5.Project 380 – Use the circuit from project 379, not 377. Project 381 – On line 5 of the second paragraph, “is turned on” should be “is turned off” and “C5”should be “C4”. Project 384 - Does not work as described, add 100Ω resistor in series with red LED to correct. Project 387 – A jumper cable should be shown connecting points A and B.Project 398 – Uses five 3-snaps but only 4 are available, use the antenna or a jumper wire as a sub-stitute.Project 410 - 3-snap across C1-E1 should be layer 2. Projects 411 to 418 – Replace the 3-snap across base grid locations A1-C1 with the photoresistor.Also, the text should say that the display is flashing when you turn on the switch, and goes off whenyou cover the photoresistor. You can add sound to this circuit by connecting the whistle chip acrossA2-C2.Project 414 – Remove “D”, add “G”.Project 419 - Place whistle chip on top of the transformer on the left side. Project 422 – Replace text with “Use the circuit in project 419, but replace the 100µF capacitor (C4)with the 10µF capacitor (C3). “Project 423 - Replace text with “Use the circuit in project 419, but replace the 100µF capacitor (C4)with the 470µF capacitor (C5). “Project 424 - Replace text with “Use the circuit in project 419, but replace the 100µF capacitor (C4)with the 10µF capacitor (C3) and connect the whistle chip across points B & C. You can also connectthe whistle chip across points C & D.”Project 425 - D3 does not fit properly on U6, you may let this part hang loose on one side and makethe connection with a jumper wire. Project 435 – Add whistle chip at base grid locations A2-C2, level 3.Project 440 – Remove the first sentence of the text. Add whistle chip at base grid locations A2-C2,level 3.Project 447 - Add speaker and two 2-snaps on right side of transformer. Project 457 – Do not use the LED in this circuit since it may get damaged. Use only the 6V lamp. Project 471 – Add segment C.Project 473 – Add segment A, remove segments D and G.Project 489 – Replace last sentence with “After the music stops, hold down the press switch (S2) tomake it continue.”Project 501 – Change the 3-snap across C2-C4 (over display D7) to the light-blue color and changethe “3” on it to a “G”. Project 508 – Remove the 3rd sentence about making sound.

Experiments 102-305 manual: [The manual revision is indicated on the bottom right of the cover. Rev F:Screw-in bulb/socket may have been replaced with a single-piece lamp. Page 2: The symbol for C3 is missing. Page 5, step 13: The drawing is wrong. Either connect the branch with R4 to the D2 side of Q1, orjust use project 128 to test the PNP transistor (Q1). Page 5, step 14: use the 100Ω resistor R1, not 1KΩ R2.Project 103: Add a 1-snap at base grid location C6, on level 1.Project 104: The references to space war sounds in the text and objective are misleading; it doesn’treally sound like that. Project 122: See the latest revision for an improved circuit. Project 123: This circuit might not make noise if you have too little or too much moisture on your fin-gers.Project 220: The circuit drawing uses ten 2-snaps, but model SC-300 only includes nine. Remove L2and instead place L1 across base grid locations D7-D9 on level 3.Project 221: Remove 2nd paragraph.Project 228: Change “here a tone” to “hear a tone”.Project 230: This project doesn’t always work. Use the whistle chip (WC) instead of the variable ca-pacitor (CV). Project 248: Replace L1 with L2. Change objective text to “To make space battle sounds.”Project 262: Swap L1 with one of the 3-snaps, replace the other 3-snap with L2, and remove the last2 sentences of text.Project 265: The drawing should show the 3-snap as being above the R5 resistor, not below it. Project 269: Add a 1-snap at D5 (level 2) and a 2-snap at C5-D5 (level 3). Project 296: Our C5 parts are now non-polarized, so this circuit won’t work. Use this circuit instead:

Quieting a Motor:

Place the fan on the motor (M1) and turn off

the slide switch (S1). Press the press switch

(S2) and listen to the motor.

As the motor shaft spins around it connects/

disconnects several sets of electrical contacts.

As these contacts are switched, an electrical

disturbance is created, which the speaker con-

verts into sound.

Turn on the slide switch and push the press

switch again. The fan spins just as fast, but the

sound is not as loud. Capacitors, like the

470µF capacitor (C5), are often used to filterout undesired electrical disturbances. If you

replace C5 with one of the other capacitors in

your set then the sound will not be changed

as much.

!WARNING: Moving parts. Do not touch the fan or

motor during operation. Do not lean over the motor.

Rev E: Project 111 – R4 is being replaced, not R5.Project 112 – R4 is being replaced, not R5.Project 123: The resistor at left is R3.Project 180 – Place the fan on the motor.Project 182 – Replace the 100Ω resistor (R1), not the 3-snap wire. Project 219 – The objective and second sentence should refer to the speaker making sound, not theLED flashing.Project 253 – The text should refer to lamp L1, not L2.Project 263: Flip C4 for best performance.Project 281: Flip C4 for best performance.Rev D: Project 109 – The text should refer to lamp L2, not L1.Project 123 – Add a 2-snap across base grid locations E5-E6.Project 139 – In the drawing, R1 should be R3.Project 174 - This is the same circuit as project 102. See Rev-F for revised circuit.Project 199 – This circuit does not always work, change D2 to C3 (+ on left) to fix.Project 215 – The unmarked resistor on the left is R5. Project 219 – This circuit does not always work. See Rev-F for revised circuit.Project 253 – Add a 1-snap at base grid location E4.Project 265 – This circuit does not always work. See Rev-F for revised circuit.Project 277 – This circuit does not always work. See Rev-F for revised circuit.Project 279 – Add a 1-snap at base grid location C3, level 2.Project 280 – The 4-snap is on level 2, not level 1.Project 288 – See Rev -F for an improved circuit, with better sound quality.Project 296 – The resistor on level 2 is the 1KΩ (R2).

Rev C: The project listing on page 7 incorrectly refers to project 233 as Electronic Golf Game, it should sayMind Reading Game.Project 102 – Text line 2 should say 100, not 1K.Project 104 – 2-snaps at F1-F2 and F2-F3 should say level 1 and level 3, respectively.Project 134 – The circuit drawing is incorrect, replace variable resistor RV with PNP transistor Q1. Project 151 – Three 2-snaps have the level marked incorrectly: D7-E7 should be on level 2, E7-F7should be on level 3, and F7-F8 should be on level 2.Project 158 – This project calls for five 3-snaps when only four are available, so replace the 3-snapacross base grid locations G7-G9 with a 4-snap across G6-G9. Project 164 – Change first line of 2nd paragraph to say: “Now turn off the slide switch. Repeat the testwith the slide switch off; you’ll notice the LED goes out much faster after you release the pressswitch.” Project 165 – In the second paragraph, (C4) should be (C5).Project 177 – Second sentence should say: “Blowing hard into the microphone turns off the lightbriefly.”Project 178 – Resistor R5 is on level 3, not level 2.Project 180 – Capacitor C2 cannot be placed next to the speaker as shown. Remove the 1-snap fromthe speaker to correct this; C2 can be mounted between levels 3 and 4 on this circuit.Project 185 – Part of the 3rd sentence should say: “appears to be on”, not “appears be on”.Project 188 – Change “(C3, in either orientation)” to “(C3, plus side on right)”.Project 197 – There should be a 2-snap connecting transistors Q1 and Q2.

Project 198 – Make these changes to improve performance: replace R5 with RV, remove 1-snap and3-snap at A3-A5 and place jumper wires at these points, place 3-snap at E1-E3.Projects 217 and 219 – The resistor cannot fit onto speaker as shown. Shift the resistor to level 2 andthe 2-snap across grid locations D3-D4 to level 3, move the 1-snap to D3.Project 225 – Text should say “Q2”, not “U2”.Project 226 – Change “get” to “got” in line 3, and change “press press” to “press the press” in line 6.Project 230 – “C5” should be “CV”.Project 232 – The text should say: “Use the circuit from project 228 shown above, but change the1KW resistor (R2) to the 100Ω resistor (R1). While holding down the press switch (S2), move theslider on the adjustable resistor (RV) around. When the slider is near the 100Ω resistor you won’thear any sound, but the circuit is still working. This oscillator circuit is making sound waves at a fre-quency too high for your ears to hear. But your dog may hear it, because dogs can hear higher fre-quencies than people can.”Project 245 – Change 4th sentence to say: “Any loud sound or vibration causes the whistle chip toproduce a small voltage, which activates the circuit. Project 253 – There should be a 1-snap at base grid location E4, on level 1.Project 262 – Flip the motor around, so the “+” side is down.Project 276 – The drawing shows the wrong circuit, and is corrected in Rev D. Project 278 – The 4-snap on the left is on level 2, not 3.Project 279 – The speaker is on level 3, not 2. Project 284 – Once activated, the sound stays on until you turn off the switch.Project 300 – There should be a 1-snap at G7.

Experiments 1-101 manual: The manual revision is indicated on the bottom right of the cover. Rev G: Project 28: Use the red or black jumper wire to connect points X & Y. Projects 51-52: See the latest revision for improved circuits. Project 69: Remove the 1-snap at C4, and add a 2-snap across C4-D4 (level 2). Project 79: Circuit was re-drawn to look nicer, but mistakes were made. It should look like this:

Projects 92-94: These are dull and don’t always work. Use these circuits instead:Project 92: Wacky Sounds:

In the circuit, the outputs from the alarm and music ICs

are connected together. Build the circuit shown and

then place the alarm IC (U2) directly over the music IC

(U1), resting on two 1-snaps and a 2-snap. There is

also a 2-snap on top of the alarm IC. Turn on the switch

(S1) and you will hear a siren and music together while

the lamp (L1) varies in brightness.

Project 93: Wackier Sounds:

Now remove the 2-snap connection between X & Y and

then make a 2-snap connection between X & Z (on

level 5). The circuit works the same way but has differ-

ent sounds.

Project 94: Really Wacky Sounds:

Build the circuit shown at left. Turn it on, press the press switch

(S2) several times, and wave your hand over the photoresistor

to hear all the sound combinations. You can make the sound

from the music IC louder by replacing the 100Ω resistor (R1)with the 2.5V lamp (L1).

Rev F: Page 6, step 5: it can be difficult to hear the sound for the resistor test, so change text to ”Build proj-ect #7 except initially use the speaker (SP) in place of the resistor, the LED should light. Then replacethe speaker with the resistor; the LED should still light.”Page 6, step 8: Change “either” to “the slide”.Rev E: Front cover: Not all versions have enough parts to build the circuit shown, project 58 should beshown. Project 15: this circuit does not always work, see Rev F for revised circuit. Project 43: Make the connection mentioned with a jumper wire, not lamp L1. Project 65: In rare cases this project may not work; see latest revision for revised circuit.Project 73 – Near end of text change “in the across its terminals” to “in the coil and a voltage acrossits terminals.”Project 84 – The circuit drawing is incorrect; see latest revision for revised circuit. Project 85: Reference in text should be to project 84, not 89.Rev D: Page 6 – On point 6, B2 should be A1, D2 should be C1, B4 should be A3, and D4 should be C3.Project 11 – If the fan doesn’t fly off even with new batteries then try pressing the switch several timesrapidly when it is at full speed.Projects 41-43 – You can make the new connection by using lamp L1 (on model SC-100 there is no3-snap available for this).Projects 56 and 59 – Some new types of fluorescent lights use electronic ballast to produce a con-stant light, and will not create the strobe effects described.Project 68 – If this project doesn’t work, swap the locations of RP and S2.Project 71 – Add “after a few seconds” to the end of the first sentence.Project 83 – The text was clarified in the Rev E manual.Projects 84-85 – These circuits do not always work, and were revised in the Rev E manual.Rev C:Parts list should say there are three 1-snaps, six 2-snaps, and three 3-snaps; not one of each.Project 4 – Resistor cannot snap onto speaker as shown, remove the 1-snap to correct.Project 10 – The red snap jumper creates a short circuit, so make the upper connection to U2 on level2 and replace the 3-snap above it with the 100Ω resistor. Also, the 2-snap across U3-SP should be onlevel 3 and the 2-snap across SP-L1 should be on level 2. Project 15 – Does not properly snap together, remove the 1-snap to correct. Project 27 – "V" (near U2) should be "Y". Project 40 – "V" (near U2) should be "Y". Project 53 – Does not properly snap together, place the resistor on level 2 and move the 2-snapacross U2-SP to level 3 to correct. Project 71 – Base grid location C3 should be marked as point C, which is referred to in the text. Projects 72 & 73 – Base grid locations A1 and C1 should be marked as points A and B, which are re-ferred to in the text. Project 76 – Remove “in the” from the 6th line of the text.Project 79 – This circuit does not work well and was re-designed in Rev D.Page 46 – The reference to page 25 should say page 28 for project 55; the reference to page 26should say page 29 for project 57.