The new S125 AVR is suitable for every alternator type, and it ensures an high current (5A) in a very small case. It is completed with over-voltage protection (shown by a yellow led) , and low speed protection (shown by a red led). The low speed protection is adjustable by means of a trimmer (freq) which allows to set the trigger point where the machine reaches the rated voltage (40-50 or 50-60 Hz); before the trigger point is reached, the generator output voltage is adjusted proportionally to the frequency; by starting from a residual of 2 V, the rated voltage is reached when the frequency is equal to the one set on the trimmer (freq), above the trigger point and up to the rated speed the voltage remains at the rated value. During this phase a compound like regulation can be obtained, with the advantages and precision of an electronic regulator. This system enables also the insertion of heavy loads without affecting the diesel engines efficiency, may they be turbo compressed or old ones. The S125 AVR has AB terminal blocks (see picture) to let in auxiliary winding (if alternator is arranged for it), and therefore the original regulator on the machine can be replaced leaving unchanged all the alternator functions. Complete with Maximum Excitement Current Protection function, controlled by trimmer named "Reg. Current".