Cmos type gate relaxation oscillator simulated to test ability of software to handle mixed signal feedback systems. Hardware was built / tested many years ago. The sim matches the timing measurements very closely. Other CMOS type gates can be used as long as the inversions match. A variation can be built without led current limiting resistors if CD4000A series CMOS parts are used. The anode side of the leds are wired so that they go to the 5V power source and the cathode side of the leads go to their respective gate outputs. The built in gate output current limiting will prevent the leds from overheating and burning out.
