Hi all,
I'm still beginner in PCB design. I wasted a lot of time to decide which program to go for. But finally I swept ashore of KiCad. I started to design a circuit and now I stick on a problem that seems quite hilarious. I can't connect VCC and GND of an N555. But see the photo. I deleted the wires already many times and reconnected but still the ELECTRIC RULE CHECKER shows that the pins are open. In fact it says Input power pin not driven by any output power pin. I don't get it.

 

Have you tried adding a "GND" symbol to the 0V line?

By the way, connecting both TRIG and RST to the same switch is going to confuse the poor thing. RESET sets the output low, and TRIG sets the output high.
And you're not going to get anywhere near enough current through R3 to operate an opto-triac.

 

I don't see any PWR flags declared?
Must have for any power and GND that is not supplied by a PWR supply source..
You only do it once for each PWR source.

 

Ian0 Yes pin 4 of N555 is wrong. It has to go to the 12V power rail.
Thanks MaxHeadRoom. I'm a beginner on KiCad.
I think I will use a BT136 TRIAC and skip the Optocoupler. The 555 delvers enough power to drive the Tirac and galvanic separation isn't there anyway.

 

Ian0 Yes pin 4 of N555 is wrong. It has to go to the 12V power rail.
Thanks MaxHeadRoom. I'm a beginner on KiCad.
I think I will use a BT136 TRIAC and skip the Optocoupler. The 555 delvers enough power to drive the Tirac and galvanic separation isn't there anyway.

You need a negative supply to drive a triac. Many triacs won't trigger in the 4th quadrant (a positive gate voltage and a negative mains voltage)