Switching

What you need is an IC called a one shot multivibrator, its a CD4047. It will take an enable signal and will output a single pulse. The pulse is adjustable based on the value of the capacitor and it has no delay. I have some project books somewhere that shows the wiring which is very simple. You can build the circuit on a piece of PC board about 1" square. The IC is available at Radio Shack for about $1.50, a couple of resistors, a 2N2222 transistor and a capacitor driving a relay. The 2N2222 transistor is good for 1 Amp and depending on what you're driving you may not even need the relay.  If you do a search for a one shot multivibrator or a monostable multivibrator, you will find what you need. Give me some more info and maybe I can help. What are you trying to drive, is it resistive or inductive ect.