Hi Guys,

I need help designing a 3 single pulse generator. Each single pulse generator is connected to the gate of a mosfet. These pulse generator will turn on 2 mosfets together then turn on the 3rd mosfet when the 2nd mosfet turns off. the 2nd mosfet has a longer turn on time. See attached file for a detailed explanation

 

How about a 4017 counter IC with a clock oscillator.

Use one of the higher outputs to disable or gate off the clock input.

Outputs 2, 3 & 4 would be the outputs, using outputs 2 & 3 through diodes to give the longer pulse.

Activating and releasing the Reset pin would allow it to sequence through the outputs.

If you need different time combinations, you can use outputs in twos, threes or mixes (combined with diodes) to get the appropriate times.

 

You could use a 555-timer configured to be a re-triggerable one-shot (monostable)


http://www.national.com/ds/LM/LM555.pdf

 

If you want to control the times with a reasonable amount of precision, using a uC would be a good bet. Have the uC control MOSFET gate drivers to minimize your turn on/turn off times.

 

If you want to control the times with a reasonable amount of precision, using a uC would be a good bet. Have the uC control MOSFET gate drivers to minimize your turn on/turn off times.

May I ask what is a uC?

 

u is for MICRO
C is for Controller.

uS microSecond
uF microFarad
uC microController

Popular uCs for hobbyists are PICMicro from Microchip and AVR from AMTEL.

They both can be programmed with C, or Assembler. They also have compilers that allow you to code the chips in BASIC.