Building a DC-DC converter

Anyone can provide me with some help on how should i build a dc-dc converter?

Some specs include 10v power supply,output should be in pulse wave modulated waveform, manually variable duty cycle, emergent stop function, 3LEDs to indicate state(Green = power on , red = load motor in operation , yellow emergent stop), chopper frequency from 2kHz to 4kHz and MOSFET is used as a switch.

Thanks in advance

Cheers

Sounds like it's more than a simple DC/DC converter. How much current? What input voltages? Why PWM out?

Hmm wanna see whats the diff between a PWM wave compare to a normal pulsation wave. Input current maybe from 0-20mA.

Not much is going to run at 0mA. What are you trying to build?