This PCB was designed by me for my Formula Student Team. The BSPD circuit is a non-programmable circuit which is used to open the shutdown circuit when hard braking occurs. It is placed behind the dashboard. In this circuit we have used EPT 3100 pressure transducer. The circuit uses a quad package dual comparator IC (LM324: A and LM324: B to compare the input signals to threshold voltages set by the potentiometers (ISense and BSE).
The comparator will compare the equivalent voltage with the pre-calibrated voltage. The BSPD circuit checks if the Brake is pressed hard and if there is greater than 5kW motor power at the same time, the BSPD output will be low (0V) when there is BSPD fault and will be high (12V) if there is fault.
We have used jlcpcb for our BSPD circuit. The quality is really good. Check the below photo for our pcb board.
TRACTIVE SYSTEM ACTIVE LIGHT:
The TSAL is supported by a mount which is LED printed. The tractive system active light illuminates GREEN when the TRACTIVE SYSTEM is active and flashes RED when it is inactive. The TS Voltage is divided using
2W resistors to bias the 6N135 opto-isolator. When it gets biased the output turns low from high. This output is connected to the inverting terminal of LM358 comparator. We have a pre charge relay which is a DPDT switch. We use one pole for the TS line and the other as Auxiliary connection. All three Auxiliary lines are pulled down. When either of them switches, the corresponding OR gates switches high and ultimately the relay is switched. The COM terminal of the relay is connected the supply. The NC terminal is connected to the Green LED, hence it illuminates until the relay
is switched. The NO terminal of the relay is connected to supply pins (4 & 😎 of a stable multi vibrator IC 555. This way we generate a 3 Hz signal when the relay is triggered. The output of the multi vibrator is connected to the Red LED.