Simple PhotoCel Circuit Needed

Good Day Experts.

I am in need of a little help. I would like to build a simple circuit to operate a 60w lightbulb.

As the light level in the room decreases, the brightness of the lightbulb would increase and visa versa.

It's a small project for my son. The lightbulb will either illuminate a sun or moon.

Thanks for your help.

You don't mention the line voltage?

Anyway a sort of quick and dirty method might be to hack a standard line voltage lamp dimmer. The guts of a basic dimmer can be seen here. Most dimmers for home use follow that scheme. Note the Pot (R1 220K Ohms). You could likely replace the pot with a good LDR (making sure the voltage limits are OK) having a dark resistance around the value of R1. This may take some playing around. Anyway, something to consider.

Thinking about it the wife has a few night lights in the house that work that way but only have a 7 watt lamp. The darker the room gets the brighter the night lights become.

Just remember if you are working with mains voltages to light the sun, moon or whatever to make sure caution is observed and this science project is safe. No exposed voltages and everything safely enclosed in a box.

Ron