I want to build a ventilation fan timer circuit. Fan starts working when switch is closed and keeps working for a set time after it is open. SAB0529 has a circuit in its datasheet for this purpose which I'm going to build. However, I have no experience using 220VAC and I have some questions.

1. Where should I connect the Ground Line in this circuit. I know where 2 hot lines going to be connected but no idea about the ground line. There is no ground in the circuit diagram.

2. Vs is getting the voltage directly from the hot line and GND pin is not connected to the ground. I know value of the Vs pin is referenced to the GND pin but I can't understand how the IC works when the connections are like this.

3. After I understand the circuit I'm going to build it on PCB. What should I use for the voltage/output pins. For lower voltages I usually go with Jacks or soldering but I don't know if it is safe for higher voltages. I want to be as safe as possible.

Any help is appreciated. Thanks in advance.

 

Hello,

I have taken the schematic and enhanced some lines that where missing.
I also marked phase and neutral for you:


Bertus

 

Hi,
As per datasheet Vs is positive supply ,but not mentioned DC. But as per drawings Vs is getting a line Ac input(phase).
Its confusing the voltage to be supply. A little bit unsafe to do it.

 

Hi,
As per datasheet Vs is positive supply ,but not mentioned DC. But as per drawings Vs is getting a line Ac input(phase).
Its confusing the voltage to be supply. A little bit unsafe to do it.

Hello,
Datasheet states direct operation from AC line is possible. However, as you mentioned I can't figure out how it is safe and how it is even working.