I have constructed a Pulse width modulating circuit that should output an amplitude of 10 Volts PWM signal. The control input signal is a 5Vpp, 100Hz sine wave and a pulse input of 10Vpp, 1kHz square wave.
I know that the VCC value controls the amplitude of the PWM output signal. However, I tried setting it to 10 volts and the oscilloscope did not display any signal. The only time the oscilloscope displays an output is when the VCC is set to 6.5 volts and below. 
The red signal is the PWM signal, the blue square wave is the pulse input and the green signal is the control signal.
Any thoughts as to why my circuit does not output an amplitude of 10V PWM signal? Please help me solve this problem.
