Utilizing the internal error amplifiers to compare the output voltage against the internal 5V reference ( Pin 14 ) allows the IC to automatically adjust the duty cycle to maintain a steady output.
TL494 Pulse-Width-Modulation Control Circuits datasheet (Rev. I) tl494 circuit diagram
The TL494 circuit diagram can be divided into several sections: Utilizing the internal error amplifiers to compare the
It compares the sawtooth against the error amplifier output. As the control voltage rises, the output pulse width narrows. 5V Reference: tl494 circuit diagram