Okay update, thanks for all your advice , it's not exactly 50hz , but Its close enough. More worried about a large changes in frequency, the 4047, drifts quite a bit from 11 to 13v's, this circuit less than 1hz. Okay the total of the 4 resistors before @12.7v was 30w, now it's 6.8w . A 77% improvement. Also using a more available mlcc ,1uf, it's a bit cheaper too .