BUY LM555 https://www.utsource.net/itm/p/11564932.html

Description: The LM555 is a highly stable device for generating accurate time delays or oscillation. Features: Timing from microseconds through hours Astable or monostable operation Adjustable duty cycle TTL compatible Temperature stability better than 0.005% per °C Applications: Pulse generation Sequential timing Time delay generation Pulse width modulation Pulse position modulation Linear ramp generator (For reference only)