Electronics Project Question

I am a first time poster, love the site. This is a great place to post this question I hope. I have very little electronics experience and want to keep this as simple as possible. What I want to do is have 4 buttons, when any of the 4 buttons is pushed it will randomly (or at least seem random to kids)pick one of 4 12v circuits to energize. Any sugestions?

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If I have very little electronics experience

Could you tell me what you mean by "little experience" ?
For instance, if I tell you : CD4060, RC, transistor and relay, does it make sense to you ?

If not, would it be possible to change the rule of your game a little :
- kid presses one of the 4 button that activates one of the four 12V circuit, then the kid is authorized to change at will a combination of switchers : Each time a switcher is switched, this change the way the buttons are connected to the four 12V circuits. There would be many possible combinations ... That would be a mean to manually change the "random" part without having to deal with "complicated" electronics parts. That would remain in the framework of basic knowledges about "electricity" instead of "electronics".
blawmt (author)  chooseausername9 years ago
I have changed my thinking some. I know what a breadboard is and I know basic components like resistors and diodes. I can wire things together I just don't have the knowledge base to use PLC's and programmable chips. Could I do something like a digital die that would oscillate very quickly (kHz) when a button was pushed and stop when released with my knowledge base? Could I scavenge something like the shocking game but instead of a player getting a shock it would activate my solenoid? Thanks
Maybe, if you feel confortable using a 555 timer and a 4017B decade counter. The schematics for those are real simple.
Oh ! I forgot about 4017 ...............

Yeah, it would be simpler than my 4060/4555 recipe =o)
Could I do something like a digital die that would oscillate very quickly (kHz) when a button was pushed and stop when released

If you mean digital dice , then you could do that with a CD4060.
This integrated circuit is a binary counter. With an appropriate set of resistors and a capacitor you can make it oscillating and counting very quickly.
I don't remember the formula to calculate the frequency and the value of the R and C ... you'll have to google a little if you want it.

The good thing with this circuit, it's that it can work with a 12V power supply. (CMOS technology can work with any voltage in the range of 3V to 15V).

This site shows a circuit using a 4060 as a timer (very low frequency).
You could use that schematic as source of inspiration, and with a better combination of resistors and capacitor (pins 9, 10 and 11) you could make it oscillate very quickly.

For your "digital dice" :

Pin 16 goes to +12V
Pin 8 goes to 0V (aka GND)
Pin 12 goes to 0V.
You will insert your "press button" between the Capacitor connected to pin 9 and the resistor connected to pin 10. When the button will be pressed, it will establish the connection between the resistor and the capacitor which form the oscillator, and the counter will count till the button is released.

The voltage of the outputs (pins 1 to 7, and pins 13 to 15) will be "randomly" set to 0V or 12V.
However, you can't use them directly to command your four 12V circuit, because :

1) the outputs are to weak to command anything that requires a lot of energy. You'll have to make an interface with some transistors and a relay (there is an example here).

2) several of the outputs may be set to 12V at the same time.
If you want only ONE at a time, you'll have to use a second integrated circuit : CD4555.

The CD4555 is a double demutiplexer. (you can find its pinout here).

Pin 16 goes to 12V.
Pin 8 goes to GND.
Pin 1, 2 and 3 go to 12V.

You connect pin 14 to the pin 7 of the counter.
You connect pin 13 to the pin 5 of the counter.
You connect pin 15 to GND.

Only one of the 4 outputs (pins 9 to 12) will be set to 12V.