from other signals delivered to the junction 48 it will be appreciated that the magnitude of deceleration signal delivered to junction 48 will be directly proportional to the magnitude of downward going change in a respective dc voltage on lines 17 18 which in turn represents the rate of deceleration of the respective vehicle wheels an excessive deceleration of a vehicle wheel indicates that that wheel is going into a skid condition the larger the deceleration of a vehicle wheel the more likely that wheel is encountering a skid condition a wheel lock detector circuit 50 also is included in the detector circuit portion 11 it is the purpose of the wheel lock detector 50 which is coupled in the manner illustrated to the bridge 19 to receive respectively the larger and smaller of the dc voltages on lines 17 and 18 to produce a wheel locked signal on line 51 when one of the signals on lines 17 or 18 indicates a locked wheel condition the wheel locked signal is delivered via a diode 52 which forms the other part of the or gate with diode 47 to the junction 48 ordinarily the wheel lock detector 50 as is described.