kybert said:
The PIC will work, however, its going to be tricky to fire a triac at such a low current.
I need about 30mA really to do the LEDs and the triac.
hi,
This is one way you could get +5V for the PIC and LED's.
Consider the Triac as being OFF, non conducting.
The capacitive reactance of C1 at 50HZ will limit the current thru the Lamp/C1 and the power zener to approx 35mA.
The voltage drop across the 5V6 zener, will reduced by the forward voltage drop of the 1N4007 diode, which charges
the Cd smoothing cap, giving approx +5V, wrt to the neutral line, this will power the PIC etc.
As the Triac is switched into conduction by the trigger transformer, the current flowing thru the Triac will also flow thru the 5V6 zener
[ thats why it has to be at least a 5Watt zener], the voltage drop across the zener is 5.6V as before.
You will always have 5.6V drop on the positive half cycle of the mains supply, that shouldn't be a problem.
The problem is the Triac trigger reference, I have shown a trigger isolation transformer.
You have not said in your posts, how you intend driving the Triac from the PIC?
Where are you going to get the mains phase cross over point reference for the dimmer control?
Please look thru the drawing, any points you dont understand... ask