Slowly turning 12v garden lights on and off

[havanajoe]

Hi all,
I'm after a circuit that will turn my 12v garden lights on slowly when switched on and then turn off slowly when switched off. Can anyone help?

 

[(*steve*)]

Yes,

(that's a not very useful answer to a very uninformative question)

What sort of lights are they? Power source? How are they switched on and off? Over what period do you want them to brighten and dim?

 

[havanajoe]

The lights will be 12v Garden lights, 20watt LED lamps X 4
The power source will be a 12 V Battery that will be charged by solar panel
The lights will be switched on by a light sensor and I want them to take about 5 seconds to turn on, they will be switched off by a timer and I want the lights to take about 5 seconds to turn off.

 

[ljcox]

I suggest you use PWM.

That would be simple and energy efficient.

It could be done very easily with a microcontroller, (PIC, PICAXE, etc.)

Or it could be done easily in hardware.

You would need an oscillator to generate the PWM signal and a ramp signal to change the duty cycle.

I expect you could do it with two 555 ICs.