Three lights in the room Solution

Http://blog.csdn.net/pipisorry/article/details/36014835

Question: There are three lights in the room, and three switches outside the room control the three lights respectively. Only when you enter the room can you see which one is on. How can I enter the room once to specify which switch controls which lamp?

Xiao Jie:

Three lights: Turn on two lights, and close one later. Go in and watch the bright ones, but the hot ones are not bright or hot.

Four lights: Turn on two lights, turn off one after a while, and then turn on a new light, bright but hot, bright but not hot, bright and hot, not bright or hot. different.

Details:

There are three unknown numbers. There are only two known values corresponding to bright and not bright. This problem cannot be solved. Other attributes need to be introduced.

(1) introduce the attribute of the duration of enabling the light

A B c three lights a turn on for a long time then turn off B turn on for a short time some turn off C don't turn on according to the light hot three degrees can solve this problem

A B c three lamps first turn a on for a long time and then turn B c on without opening according to a is hot B is bright C is not bright can also solve this problem

(2) extend this attribute

A B c three lights enter the room to connect a light with resistance (the three lights should not be in series, if it is in series, it makes no sense to set three switches) Turn on B, according to a light is not very bright B light C light is not light solve this problem

A B C three lamps are connected to three lamps in different sizes. This problem can also be solved based on the brightness and darkness of the lamps.

(3) introduce the flashing Property

Based on the Flash speed.

Conclusion: there must be an interval such as (0, 1.

Partial solution:

When three lamps are thermostatic lamps:

Remove the light from a room and open the door with colored paper on one of the remaining two bulbs (to make the light of the two lights different, do not pull the curtain (you should be able to see whether the curtain is bright from the room with a switch), then 1. Try to switch the curtain one by one, if the light is not on, the switch is to be removed. 2. The switch is determined based on the light color.

1. Prepare a rectification diode. 2. go to the room with a switch, and set the Switch number to 1, 2, 3, and 3. set 1 to enable, 2 to disable, and 3 to enable the cover. Record the rectifying diode into the loop and enable it again. 4. to the other room, we can see that the light is on the 1st, the light is on the 2nd, and the light is on the 3rd.

Ref:

Http://blog.csdn.net/pipisorry/article/details/36014835

Http://blog.csdn.net/kupepoem/article/details/10752333

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