  We present time-series B, V photometry of NGC 6229, obtained with the purpose
of providing the first extensive CCD variability study of this cluster. As a
result, we were able to obtain periods for all NGC 6229 variables, with the
exception of five stars from the Borissova et al. (1997) candidate list located
very close to the cluster center. Two variable stars suspected by Carney,
Fullton, & Trammell (1991) are first-overtone RR Lyrae (RRc) stars, whereas
seven of the 12 candidates from Borissova et al. (1997) are confirmed variables
-- three of them being fundamental RR Lyrae (RRab) pulsators, two
first-overtone pulsators, one eclipsing binary (most likely an Algol system)
and one bright star whose variability status could not be satisfactorily
determined. A new image subtraction method (ISM) suggested by Alard (1999) has
been employed which, together with the Welch & Stetson (1993) technique, has
allowed us to discover twelve new RR Lyrae variables in the cluster, for which
ephemerides are provided. Ten of these are RRab's, whereas the other two are
RRc's. As originally suggested by Mayer (1961), NGC 6229 is clearly an
Oosterhoff type I globular cluster. We also confirm that V8 is a Population II
Cepheid of the W Virginis type, and suspect that this is the case for V22 as
well.
  The physical properties of the NGC 6229 RR Lyrae population are compared
against those of M3 (NGC 5272) using several different methods, including a
standard period-shift analysis. Possible differences between these two clusters
are discussed.
