Using SAB0529 integrated circuit can be build a very simple timer with a programmable time between 1 second and 31 hours and 30 minutes. This electronic circuit can be used for staircase lights, battery chargers, etc.
The chip is programmed using E-I pins with switches S1-S4. When S1 is closed, IC is valid for a period of 1 h, with S2: 4 h, with S3: 10 h, with S4: 16 h; all combinations are possible between them: for example, if S2 and S3 are closed, and the other two switches are open, the chip is enabled for a period of 14 h IC drive a 4A triac, which can act pretty big task. Timer starts with S5.
In case of emergency, it can be stopped with S6.