Recommended Project 4 - Miniature Real-time Controller

  • The circuit uses only three chips, a 89C2051, DS275(or MAX232), and 74LS07 open collector driver.
  • The scheduler for time on/off of 6-channel output can be made by downloading from PC and saved into onchip RAM.
  • Each output provides a 20mA sinking suitable for driving a homemade opto-triac or big solid-state relay for heavy load.
Details can be found HERE