I am looking for a way to activate three small led's, one at a time in a ramdom order. The start of the sequence will start with the movement of a micro mercury switch.

Help!!!!!!!!


I am looking for a solution to this small project, if there is help out there please let me know.

Thank You soooo much,

Lawrence

 

You shouldn't post your email address in open form. The only people who will usually answer this way is spammers, who use automated spam bots that harvest such addresses. Next time you read this you should remove them. You'll get your answers publically, on this post. That is how it works.

 

thank you for helping a rookie

 

For me the random is the hard part. I've made random generators by using a counter connected to the oscillator through a button. We might be able to do something similar with the mercury switch. Is it normally open or normally closed, and do you care if the all the lights are lite while it is in the odd state?

 

You can make something which is not random in reality but looks like random. Take a 4-bit counter and pulse it with a clock. Connect its outputs to a seven segment led driver and connect each led to one of this seven segment driver outputs. The outputs of the seven segment driver will switch on/off according to the output value of the counter and thus the leds will switch on/off. This of course is not random but for one who does not know it seems random.
If you like you can use an up/down counter and force the counter to count up or down between some time delays and thus create a more random on/off.

 

once the unit is activated the mercury switch will start the process and only one lEDwill come on until it times out then all is off. the next time the mercury switch is activated the process starts over and again a lED is turned on and stays on until it is timed out or until the mercury switch is again activated.

Size is very important, 2" sq by 1" high

 

The Idea of ramdon is up for question it might be better if the three LED's were set as 1 at 60% of the time, 1 at 30% of the time , and 1 at 10% of the time. in truth it only has to look ramdom.

The mercury switch was thought of only because you have to pick this unit up and roll it over to look at the response.

does this help?????

 

You can use two 555 to make this. Use the one 555 as a monostable, which will be activated by the switch, to drive the enable input of the other 555 which will be connected in astable mode and thus pulsing the counter. Once the first 555 triggers it will enable the other until its output goes to zero. You can move the thing during the timing but to get the leds stopped at some random positions you need to stop moving the thing around just a bit before the first 555 output goes low. If you move it gain it will start the random led on/off.

 

Thank you for the direction. Now it's off to the drawing board and see how small i can get it and have it work. it sounds good however I now need to put it into action which will bring up other requirements i'm sure.

Thank you your time and everyone esle also.

 

still no luck on the schematic for this problm. any help in finding a solution?

 

Does the sw. close & open a number of times on one roll? My take 5 555's[ 2 556+1 555 or 1 555 & 1 558]. First is oscillator, 2nd ,lock out 2-3 sec. 3-4 ring counter with attached LED's. Roll the die triggering lock-out which enables osc. oscillator drives ring; lock-ott resets stopping osc. preserving count.Something is still missing.

 

WE need two time delays, first [ 1-2 sec.] enables unit to count as it rolls and ,when it times out second delay preserves the count for a few seconds while unit is turned face up. First delay starts a clock driving a sequential counter with three associated LED's,ie 4017 with reset fed back to output 3.

 

Your three random LED gen schematic is ready.

 

One possible problem: outputs IC 1 A & IC 2 B may not drop below .7V.might add dividers to outputs, 10kΩ to outputs and to 3.3k and ground.center tap to resets.

 

At 12V input,change 680Ω to i.2kΩ.