Email OF The Day: 06/27/13

Thursday, 27 June 2013

[www.keralites.net] Digitally Adjustable Dancing Lights

Digitally Adjustable Dancing Lights

You might have come across several types   of adjustable dancing lights (flickering LEDs). Most of them use presets   (variable resistors) to adjust the rate of switching. Being a   mechanical component, the preset easily wears out with use and also   introduces noise in the circuit. The circuit presented here selects   different values of resistors to control the frequency of an astable   multivibrator using timer IC 555.

The circuit is built around   decade counter IC 4017, quad bilateral switch IC 4066 (to select the   desired resistance) and timer 555. The decade counter output selects one   of the resistors at the output of IC 4066. The selected resistor   changes the time period of the 555 timer circuit, whose 'on' and 'off'   timings are given by:
ton = 0.693(R9+Rx)C3
toff = 0.693RxC3
  		  			  			
Fig. 1: Circuit for digitally adjustable dancing lights
In   the present design, R9 = 1 kilo-ohm, C3 = 47 µF and Rx varies according   to the output of IC1 (CD4017), which changes by pressing the switch S2   one by one.

When
Rx=R5=5.6 kilo-ohms, ton=0.214969 second, toff=0.182398 second
Rx=R6=10 kilo-ohms, ton=0.358281 second, toff=0.325710 second
Rx=R7=22 kilo-ohms, ton=0.749133 second, toff =0.716562 second
Rx=R8=33 kilo-ohms, ton=1.107414 second, toff=1.074843 second
  		  			  			
Fig. 2: Optional circuit
Whenever   you momentarily press switch S2, the output of the decade counter   advances to select a higher value of resistor Rx in IC 4066, which   changes the switching time of the astable multivibrator. LED1 and LED2   indicate switching 'off' and 'on,' respectively, of the multivibrator.

Assemble   the circuit on a general-purpose PCB and enclose in a suitable case.   Fix LEDs and switches on the front panel. Connect the optional circuit   shown in Fig. 2 if higher intensity of light is needed.

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[www.keralites.net] World's Longest Mustache Measures over 4 Meters

Ram Singh Chauhan started growing his moustache in 1970, and hasn't cut it since. Today it measures over 4.30 meters, and the proud Indian man from Rajasthan holds the Guinness record for World's Longest Moustache.

The 58-year old says one of the secrets to impressive facial hair growth is starting early. "As you grow old your hormones grow weak, so the speed slows down," Ram says, but even now he still adds a few centimetres to his moustache every year. He stopped shaving his moustache back in 1970, after being inspired by a fellow moustache enthusiast from Rajasthan, resuming to trimming the split ends every once in a while. In the early years Chauhan and his wife Asha used to fight over his abnormally long facial hair, because he used to take a long time to wash and groom it, and people stared at them every time they went out. But as soon as her husband started getting recognition for his efforts, she began to respect his commitment, and says she now considers the moustache part of the family and shares his pride in it. Thanks to his long moustache, Ram Singh Chauhan appeared in big movies like 1983's "Octopussy", starring Roger Moore, as well as numerous Bollywood productions. He has also travelled around the world, to show off his amazing whiskers.

Ram's moustache currently stands at over 4.30 meters, and taking proper care of it is no easy task. The Rajasthan state tourism official takes between one and two hours a day to clean and comb his precious facial hair. "I massage it and oil it regularly and I wash it every 10 days which takes a long time," he told BBC News. "My wife helps me." Walking around with over 4 meters of hair hanging from your face is also pretty tough. When the moustache was shorter, Chauhan used to wrap it around his ears, but these days he has to roll both ends around his neck. But he knows there's no gain without pain and he wouldn't dream of getting rid of it. It's what makes him special, and that makes everything worth it.

Ram Singh Chauhan's biggest regret is that his son doesn't share his passion for long facial hair. He doesn't even have a tiny moustache.

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