Hi! First of all, I'm new to the forum, so this is my first thread. I'm bit of a beginner in electronics, so some of my question may be noobish 
So, the question itself. I need to design a circuit for school project. It must be done without programmable devices.
The task goes like this - design circuit which turns on 3 different light sources, during the first hour after dark. It must be a random process, like each day the order or exact time of switching changes. Between 23:00 and 24:00 the lights must be turned off, once again like a random process. Of course I have to make sure, the lights stay off during the night. Basically it's like simulating 3 apartments with people living in them.
So my idea is something like this. There's a decade counter like 4017, which gives a pulse in every output every 50 min or so. It keeps counting all the time, that way I get something like a random process. When sun sets photodiode circuit allows the counter pulses through AND logic gate. Then it has an op amp circuit with electrically controllable gain (+1 or -1) which determines either the lights are switched on or off by the pulses. The on or off pulses go to comparator which turns on or off SSR. The problem is with the gain control, gain should be flipped at 23 and then flipped again at the morning. But I have no idea how to make this time control circuit.
So is the basic idea any good or am I making it harder than it should be? Also any suggestions are welcome
//Sorry for my english. Hope you can understand the text.
So, the question itself. I need to design a circuit for school project. It must be done without programmable devices.
The task goes like this - design circuit which turns on 3 different light sources, during the first hour after dark. It must be a random process, like each day the order or exact time of switching changes. Between 23:00 and 24:00 the lights must be turned off, once again like a random process. Of course I have to make sure, the lights stay off during the night. Basically it's like simulating 3 apartments with people living in them.
So my idea is something like this. There's a decade counter like 4017, which gives a pulse in every output every 50 min or so. It keeps counting all the time, that way I get something like a random process. When sun sets photodiode circuit allows the counter pulses through AND logic gate. Then it has an op amp circuit with electrically controllable gain (+1 or -1) which determines either the lights are switched on or off by the pulses. The on or off pulses go to comparator which turns on or off SSR. The problem is with the gain control, gain should be flipped at 23 and then flipped again at the morning. But I have no idea how to make this time control circuit.
So is the basic idea any good or am I making it harder than it should be? Also any suggestions are welcome
//Sorry for my english. Hope you can understand the text.
