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Latest Issues

July 2008

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C I R C U I T L A B

1) PC Multimedia Speakers (New)
2) Three-Phase Appliance Protector (New)

Click to view in order of 'highest hits first'

S No.	Circuit Name	Hits
1	Aquarium Probe	2297
2	Bicycle Indicator	2098
3	Poor Man’s Hearing Aid	1747
4	Portable Lamp Flasher	2720
5	Staircase Light With Auto Switch-Off	4560
6	Car Anti-theft Guard	3907
7	USB Power Booster	6695
8	Smart Vibration Sensor	5244
9	Drinking Water alarm	8510
10	GLOW PLuG CONTROLLER	4010
11	Versatile CMOS TTL Logic And Clock Probe	2843
12	Tester For Remote Control	6921
13	Automatic Low-Power Emergency Light	11966
14	Mobile Bug	13999
15	LED Lighting for Christmas	10522
16	Current Sensor	11082
17	Seismic Sensor	9514
18	Dice With 7-Segment Display	7629
19	Motorbike Alarm	12426
20	Laptop Protector	16976
21	Shutter Guard	7257
22	Desktop Power Supply	11759
23	Mobile Shield	16752
24	Infrared Firecracker Igniter	12244
25	Automatic Phase Changer	12970
26	Flying Saucer	16393
27	Anti-Collision Rear Light	13173
28	Light Fence	13831
29	MAT Switch	11639
30	5-Band Graphic Equaliser	11391
31	Clock Timer	19210
32	Fully Automatic Emergency Light	24223
33	IR Music Transmitter and Receiver	28255
34	Electronic Horn	17245
35	Ultrasonic Proximity Detector	20603
36	Secret Bell	24303
37	Variable Power Supply Using a Fixed-Voltage Regulator IC	28099
38	Appliance Timer-Cum-Clap Switch	14408
39	Telephone-Operated Calling System	20297
40	Front Door Guard	21508
41	Bell-Cum Light Controller	14091
42	Friendly Charger for Mobile Phones	23918
43	Hearing Aid	18585
44	Speed Control of DC Motor Using Pulse-Width Modulation	24617
45	Remote-Controlled Fan Regulator	40644
46	Low-Power Voltage Doubler	15479
47	Parrot-Sounding AC Doorbell	15396
48	Multi-Melody Generator With Instrumental Effect	11884
49	School/College Quiz Buzzer	13753
50	Visual AC Mains Voltage Indicator	14921
51	Simple Short-Wave Transmitter	16091
52	Solar Lighting System	41966
53	Infrared Bug	26180
54	Picnic Lamp	21699
55	Versatile Power Supply	22904
56	Ultrasonic Proximity Detector	27914
57	Shadow Alarm	30691
58	IR Burglar Deterrent	34671
59	Versatile Water-Level Controller	27813
60	Automatic-Off Timer For CD Players	19549
61	Heat-Sensitive Switch	21858
62	Sensitive Vibration Detector	21575
63	Digital Dice	23713
64	Remote-Controlled Power-Off Switch	38937
65	Little Door Guard	28008
66	Stress Meter	26598
67	Teleconferencing System	30742
68	Medium-Power FM Transmitter	33937
69	Smart Cellphone Holder	27660
70	Fuel Reserve Indicator For Vehicles	25200
71	Brake Failure Indicator	27737
72	Safety Guard	21061
73	Mains Supply Failure Alarm	22352
74	Remote Control For Home Appliances	63455
75	Micromotor Controller	31402
76	Solar Bug	33448
77	Simple Digital Security System	37622
78	Digital Audio/Video Input Selector	20637
79	Auto Turn-Off Battery Charger	39366
80	Atmel AVR ISP Dongle	28131
81	Audio Amplifier for Personal Stereo	38614
82	Musical Light Chaser	32675
83	Water-Level Controller	54821
84	Hit Switch	34581
85	Fire Alarm Using Thermistor	33405
86	Electronic Watchdog	45901
87	Automatic School Bell	29869
88	Anti-Theft Alarm For Bikes	43427
89	DC Motor Control Using A Single Switch	34665
90	Solidstate Remote Control Switch	32227
91	Flashing-Cum-Running Light	28758
92	Quality FM Transmitter	64686
93	Stabilised Power Supply With Short-Circuit Indication	28599
94	Digital Stop Watch	39482
95	Cell-Phone-Controlled Audio/Video Mute Switch	44626
96	PC-Based DC Motor Speed Controller	49645
97	Child's Lamp	37865
98	Watchman Watcher	33794
99	Highway Alert Signal Lamp	26294
100	Low-Cost Electronic Quiz Table	24199
101	Mobile Cellphone Charger	58709
102	Smart Foot Switch	30039
103	Programmable Timer for Appliances	46563
104	Anti-Bag-Snatching Alarm	25808
105	LED-Based Message Display	68863
106	Multiband CW Transmitter	28216
107	Automatic Night Lamp With Morning Alarm	51924
108	Touch Dimmer	47473
109	Mosfet-Based Preamplifier for FM Radio DXing	33993
110	Non-Contact Power Monitor	25145
111	Remote-Operated Musical Bell	41520
112	Electronic Motor Starter	45015
113	Telephone Receiver	64123
114	Washing Machine Motor Controller	41863
115	Low-Cost Hearing Aid	38317
116	Over-/Under-Voltage Protection of Electrical Appliances	33292
117	Parallel Telephone With Secrecy and Call Prevention	39097
118	Voltage-Based Controller For Switches	22838
119	DTMF Receiver IC MT8870 Tester	51584
120	Pulse Generator	40892
121	Infrared Remote Control Timer	47853
122	Clap Switch	77991
123	Multi-Switch Doorbell With Indicators	26971
124	Song Number Display	36499
125	Lead-Acid Battery Charger With Voltage Analyser	53976
126	Electronic Security System	103153
127	Three-Colour Display Using Bicolour LEDs	44622
128	Ultra-Bright LED Lamp	66316
129	Computerised Universal Timer	36929
130	Number Guessing Game	31922
131	PC-Based Oscilloscope	212161
132	Intruder Radio Alert System	45699
133	Flashing Beacon	41453
134	Knock Alarm	56533
135	Automated Traffic Signal Controller	65747
136	Infrared Toy Car Motor Controller	176198
137	Mains Manager	33157
138	Crystal-Controlled Time-Base Generator	25817
139	Mains Operated Christmas Star	28141
140	Music On-Hold For Telephones	34881
141	Solidstate Switch For DC-Operated Gadgets	26515
142	Ding-Dong Bell	60038
143	IR Remote Switch	86021
144	Shortwave Transmitter	41747
145	FM Booster	86045
146	Laser Torch-Based Voice Transmitter And Receiver	67799
147	Mobile Phone Battery Charger	58535
148	Fastest Finger First Indicator	43905
149	Condenser Mic Audio Amplifier	57331
150	DarkRoom Timer	34962
151	Speller Effect Sign Display	29329
152	Stereo Tape Head Preamplifier For PC Sound Card	35033
153	A Hierarchical Priority Encoder	22011
154	Digital Mains Voltage Indicator	39717
155	Water-Level Controller	71183
156	Invisible Broken Wire Detector	63892
157	Anti-Theft Security For Car Audios	41523
158	Simple Telephone Ring Tone Generator	40889
159	Versatile Zener Diode Tester	33141
160	DTMF Proximity Detector	58093
161	Under-/Over-Voltage Beep for Manual Stabiliser	24422
162	15-Step Digital Power Supply	56206
163	Auto Shut-off For Cassette Players And Amplifiers	26444
164	House Security System	99907
165	Generation Of 1-Sec. Pulses Spaced 5-Sec. Apart	20268
166	9-Line Telephone Sharer	57426
167	Musical ‘Touch’ Bell	49338
168	Automatic Heat Detector	46238
169	Single Phase Electronic Starter	25655
170	Precision Amplifier With Digital Control	35007
171	Precision Attenuator With Digital Control	21907
172	Infrared Electronic Shooting Game	10922
173	Telephone Ringer Using Timer ICs	28653
174	Blown Fuse Indicator	26236
175	Automatic Speed-Controller For Fans and Coolers	41835
176	2-Line Intercom-Cum-Telephone Line Changeover Circuit	30852
177	Low-Cost PCO Billing Meter	32775
178	Telephone Line Based Audio Muting And Light-On Circuit	20642
179	Power-Supply Failure Alarm	38550
180	Add-On Stereo Channel Selector	21799
181	Parallel Telephones With Secrecy	28206
182	Telephone Number Display	55917
183	Luggage Security System	35579
184	Precision Digital AC Power Controller	28865
185	Phone BroadCaster	27509
186	Telephone Call Meter Using Calculator And COB	26666
187	Telephone Conversation Recorder	34291
188	Universal High-Resistance Voltmeter	19829
189	Protection For Your Electrical Appliances	25377
190	Simple Code Lock	43751
191	Time Switch	28534
192	Digital Speedometer	26165
193	Long-Range FM Transmitter	177327
194	Self-Switching Power Supply	25763
195	Electrical Equipment Control Using PC	69853
196	Teleremote Control	42432
197	Low-Cost Transistorised Intercom	29744
198	Charge Monitor For 12V Rechargeable Lead-Acid Battery	50976
199	Cordless Phone Backup	25267
200	Sleep-Switch Cum Wake-up Timer	20741
201	Simple Analogue To Digital Converter	28856
202	Dual-Channel Digital Volume Control	28495
203	Infrared Cordless Headphone	60342
204	Magnetic Proximity Switch	22455
205	Simple Low-Cost Digital Code Lock	35167
206	Ultra Low Drop Linear Regulator	12038
207	Simple Sensitive Remote Control Tester	13716
208	Electronic Scoring Game	17207
209	Tiny Dew Sensor	17989
210	Electronic Jam	40289
211	Precision 1Hz Clock Generator Using Chip-On-Board	14002
212	Digital Switching System	24610
213	40-Metre Direct Conversion Receiver	22552
214	Frequency Measurements Using PC	25017
215	Contactless AC Mains Voltage Detector	14539
216	PC-Based 7-Segment Rolling Display	22917
217	Electronic Card-Lock System	46170
218	Miniature Strobe Light	20293
219	Automatic Dual-Output Display	14016
220	CD-ROM Drive As Digital-Audio CD-Player	38109
221	Clap Remote	21664
222	Wiper Speed Controller	17944
223	Water Level Indicator With Alarm	33371
224	IC Controlled Emergency Light With Charger	37269
225	Auto Reset Over/Under Voltage Cut-Out	7280
226	Smart Phone Light	13584
227	Automatic Emergency Light	21595
228	Telecom Headset	13005
229	Automatic Room Power Control	17209
230	Handy Zener Diode Tester	9434
231	Telephone Line Vigilant	9666
232	High and Low Voltage Cutout With Delay and Melody	7817
233	Colour Sensor	22227
234	Running Message Display	19208
235	Low Current, High Voltage Power Supply	10433
236	Audio-Visual Extra Ringer For Phone	6016
237	Solidstate Auto Power-Off/On Mains Failure	5698
238	7MHz CW/AM QRP Transmitter	7647
239	Intelligent Switch	17323
240	Fluid Level Detector	12519
241	Programmable Door-Bell With Flashing LEDs	9231
242	Clap Switch	13909
243	Computerised Morse Code Generator/Transmitter	6191
244	Accurate Electronic Stop-Watch	7662
245	Magic Lights	18991
246	Digital Dice With Numeric Display	9857
247	Sensitive Temperature Switch	10308
248	Automatic Temperature Controlled Fan	15144
249	Watch-Dog for Telephones	9770
250	FM Transmitter For Channel Changer	16753
251	UPS For Cordless Telephones	17747
252	Touch-Sensitive Musical Bell With Timer	7262
253	Programmable LED Indicator	11033
254	Economical Pump Controller	9476
255	Fire Alarm	17357
256	Short Wave AM Transmitter	11068
257	Automatic Emergency Torch	10524
258	Ramp Controlled Light	7029
259	Simple Intercom Circuit	13700
260	Tank Overflow Preventer	11524
261	33-Volt Tunning Voltage	8032
262	Appliance Timer	8942
263	Electronic Code Lock	17096
264	Flashing Brakelight	8532
265	IR Remote Control	20721
266	Car Anti-Theft Wireless Alarm	17108
267	Divide-By-N Counter Realisation Using ICs CD4033 And CD4017	9515
268	Soft Musical Telephone Ringer	6387
269	Low Cost Transistorised Inverter	14828
270	Automatic Telephone Answering Machine	13447
271	Hourly Chime Function Generator	6927
272	Programmable Priority Time Switch	8192
273	Digital Volume Control	16283
274	Extension Phone Switcher	6555
275	Battery Opeated High Voltage Source	10651
276	Handy Telephone Receiver	10382
277	A Highly Efficient DC Lamp Dimmer	8333
278	Low Cost Automatic Gate LIght With A Musical Bell	9277
279	Automatic Switch For Audio Power Amplifier	9392
280	Capacitance Bridge	9678
281	Darkness Controlled Light Switch	14386
282	AF/RF Signal Tracer	11021
283	Automatic Temperature Controller	14589
284	Simple Logic Probe	7618
285	Telephone Amplifier	9004
286	Ready -To-Use Object Counter	9157
287	Four-In-One Burglar Alarm	10463
288	Telephone Call Counter	11433
289	Water Level Controller Using 3-Phase Starter	10386
290	Running Lights Effect	11465
291	Programmable Musical Bell	7092
292	Solidstate Relay with Under/Over Voltage Protection	6116
293	Adjustable Dancing Lights	7139
294	Ultrasonic Switch	10551
295	Off-Line Telephone Tester	5611
296	Dancing Lights	11759
297	Versatile Variable Duration Digital Timer	4083
298	Programmable 8-Digit Code Lock	8036
299	Add Auto Start To Generators	4820
300	Sound Controlled Flip-Flop	5525