The circuit uses two timer/oscillators connected as a Pulse Width Modulator. The chip used is an nmos dual timer/oscillator, NE556. This IC has two 555 timers in one 14-pin IC package.
http://www.ozitronics.com/docs/k67v3.pdf
DC motor PWM controller that takes the 1ms to 2ms pulse from the RC receiver and converts it into a pwm train at 1Khz. design is based around three parts.
http://www.math.niu.edu/~behr/RC/AP/ap-digital.html
This electronic speed control is suited for small electric planes. It has propeller brake and exponential speed growth. It has propeller brake and exponential speed growth.
http://www.rcdesign.ru/eng/electronics/esc/