A laser level with a sensorless DC motor controller having a feedback
sampling circuit connected in parallel with the coil to sense back EMF.
An integrator provides a feedback signal from the sensed back EMF, which
the amplified difference from a reference level is used as a pulse width
control signal. A pulse width modulation generator uses the control
signal to generate variable "on" time pulse widths for each motor drive
pulse such that high resolution is provided to the DC motor, permitting
accurate rotor position at low rotational speeds. It is emphasized that
this abstract is provided to comply with the rules requiring an abstract
to allow a searcher or other reader to quickly ascertain the subject
matter of the technical disclosure. It is submitted with the
understanding that is will not be used to interpret or limit the scope or
meaning of the claims.