The CPC1390G is a 4-pin, single pole and normally open solid state relay that has input to output isolation of 5000 Vrms. It has a blocking voltage of 400 Vp and does not generate EMI or RFI ...
Many integrated circuits have undocumented features or abilities. This is one of them. The TLC555 output (pin 3) can sink a 100mA load to 1.28V. The open drain transistor reset (pin 7) can sink 100mA ...