Velleman dc to dc pulse width modulator kit velleman k8004 p a kit of parts to build a control circuit suitable for the precise control of dc motors brightness regulators small heaters and much more p p the circuit converts a dc voltage into a row of pulses the duration of which is proportional to a control voltage the big advantage is that almost no performance is lost in the control circuit the design incorporates protection against overload and short circuits p velleman k8004 d