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#67665 07/11/06 09:44 PM
Joined: Nov 2001
Posts: 75
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Bill39 Offline OP
Member
Here's one my son brought home from school and so far he's got me stumped:

Create a circuit in which initially, four lamps are ON while the fifth lamp is OFF. Also, you must be able to unscrew one of the four burning lamps in order to turn on the fifth lamp. You are not allowed to change any of the wiring to get this to work.

Darn College-boy!!

#67666 07/11/06 10:24 PM
Joined: Jul 2004
Posts: 9,771
Likes: 14
G
Member
What kind of parts can I use?


Greg Fretwell
#67667 07/11/06 10:29 PM
Joined: Nov 2001
Posts: 75
B
Bill39 Offline OP
Member
A battery, the lamps, (& holders) & any # of wires you need.

That's it, no switches, etc. A simple circuit connected in any combination of series or parallel.

#67668 07/11/06 10:31 PM
Joined: May 2003
Posts: 2,876
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e57 Offline
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Thyristor, zenor diode and SCR to control a relay? Multiples of each could do it arranged correctly, oh a few resistors too. Also what is the voltage and current?

You posted while I was pondering...

[This message has been edited by e57 (edited 07-11-2006).]


Mark Heller
"Well - I oughta....." -Jackie Gleason
#67669 07/11/06 10:32 PM
Joined: May 2003
Posts: 2,876
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e57 Offline
Member
Hmmm, not legal to install? But operational?

[This message has been edited by e57 (edited 07-11-2006).]


Mark Heller
"Well - I oughta....." -Jackie Gleason
#67670 07/11/06 10:37 PM
Joined: Jul 2004
Posts: 9,771
Likes: 14
G
Member
Are all of the light bulbs the same wattage?
If the 5th one was a small fraction of the others and in parallel with the one you unscrew it would work.
It sounds like one of those "all american five" radio filiment deals.


Greg Fretwell
#67671 07/11/06 10:39 PM
Joined: May 2003
Posts: 2,876
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e57 Offline
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Voltage and lamp wattage?

You guys got me again in the two minute delay of my slow typing...

[This message has been edited by e57 (edited 07-11-2006).]


Mark Heller
"Well - I oughta....." -Jackie Gleason
#67672 07/11/06 10:42 PM
Joined: May 2003
Posts: 2,876
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e57 Offline
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Thats what I was thinking too.


Mark Heller
"Well - I oughta....." -Jackie Gleason
#67673 07/11/06 10:46 PM
Joined: Nov 2001
Posts: 75
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Bill39 Offline OP
Member
Guys,
This is a college physics lab question.
No NEC code or inspectors to worry about.

Wattage of lamps was not given. The info in my original post is all the info the prof gave them.

#67674 07/11/06 11:16 PM
Joined: Jul 2004
Posts: 787
L
Member
Hint: Brooklyn

LarryC

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