Chaotic synchronization is studied in experiments performed on dynamic arrays of Chua's circuits that are connected by using a recently introduced driving method specially suited for the design of such arrays. Namely, the driven circuit has the same number of energy storage elements as the driving circuit. The experimental results, that are supported by theoretical analysis, are different depending on the geometric arrangement of the array. In the case of linear arrays the first circuit always imposes its behavior to the rest of the chain at a finite velocity. Instead, in the case of ring geometries the chaotic synchronized state is only stable upto a certain size of the ring. Beyond this critical size a desynchronizing bifurcation occurs, leading to a chaotic rotating wave that travels through the array. This instability is explained by performing an analysis in terms of modes.