Archive for the Category


ULN2003 Control Stepper Motor by Parallel Port

Thursday, May 15th, 2008


This is an easy to build stepper motor driver that will allow you to precisely control a unipolar stepper motor through your computer’s parallel port. With a stepper motor you can build a lot of interesting gadgets such as robots, elevator, PCB drilling mill, camera panning system, automatic fish feeder, etc. If you have never [...]

sequences supplies for FPGAs

Wednesday, April 16th, 2008


System designers must consider the timing and voltage differences between core and I/O power supplies (in other words, power-supply sequencing) during power-up and power-down. The possibility of a latch-up failure or excessive current draw exists when power-supply sequencing does not occur properly. The trigger for latch-up may occur if power supplies apply different potentials to [...]

DC to Pulse Width Modulator

Wednesday, April 9th, 2008


This control circuit is suitable for the accurate control of DC motors, lighting levels, small heaters as well as other applications. The circuit converts a DC voltage into a series of pulses, such that the pulse duration is directly proportional to the value of the DC voltage. This circuit can operate with 8-35VDC and control [...]