A automobile brake failure indication circuit is a backup system meant to alert drivers of any issues with their cars braking system.
Usually, it monitors the brakes using electrical components alerting the user with an aural or visual signal if a problem is found.
Only automobiles having negative grounding will be able to use the circuit.
A brake switch failure signal is also provided by it.
The rear brake lamps of cars with hydraulic braking systems are controlled by a brake switch installed on the brake cylinder.
Due to leakage, the fluid pressure must drop for the brake switch to activate, which is why it is fluid operated.
Only when there is a significant pressure loss in the brake pedal can the fluid leak be easily identified.
Every time you use the brake, this circuit alerts you to the possibility of a brake failure by keeping an eye on the brake switch.
Circuit Working:
Parts List:
| Category | Item | Quantity | Power Rating |
|---|---|---|---|
| Resistors | 10k | 5 | 1/4 watt |
| 100k | 1 | 1/4 watt | |
| 470k | 1 | 1/4 watt | |
| 470Ω | 2 | 1/4 watt | |
| Capacitors | Ceramic 0.02μF | 1 | – |
| Ceramic 0.01μF | 1 | – | |
| Electrolytic 1000μF 25V | 2 | – | |
| Electrolytic 10μF 25V | 2 | – | |
| Electrolytic 100μF 25V | 1 | – | |
| Semiconductors | IC 77812 | 2 | – |
| IC 555 | 1 | – | |
| IC CA3140 | 1 | – | |
| LEDs (red and green) 5mm | 1 each | – | |
| Diodes 1N4007 | 2 | – | |
| Components | Buzzer | 1 | – |
Either a basic perfboard or a generic printed circuit board PCB can be used to construct the circuit.
It functions as a voltage comparator by use of an operational amplifier op amp integrated circuit IC, most especially the CA3140 IC2.
The IC 555 IC3, an additional integrated circuit, is set up in a monostable state to provide a timed alarm signal.
The voltage across the brake switch is continually monitored by the op amp IC2.
Through two potential divider resistors, a reference voltage is supplied to its non inverting input.
By use of a diode and a voltage regulator IC1 coupled with an additional resistor, the inverting input is linked to the brake switch.
With this configuration, when the brake pedal is depressed a greater voltage is applied to the inverting input.
Normally, while the brakes are not engaged, the op amps IC2 output remains high maintaining the light on a red LED1.
The voltage at the op amps inverting input shifts as the brake pedal is depressed.
This causes the op amp to produce a low output signal, which shuts off the red LED.
In addition, a brief voltage pulse is transmitted to the timer integrated circuit IC3 via a capacitor.
The 555 IC3 is configured in a monostable mode which means that when it is activated, it will produce a single pulse with a predetermined duration (regulated by resistors and a capacitor).
In this instance, the one second pulse turns on a buzzer and an additional LED2.
The presence of this one second beep and flash indicates that the brakes are in good working order.
Pressing the brake pedal wont cause the voltage to change much if there is an issue with the brakes, such as a leak that is creating a pressure decrease in the system.
This implies that the buzzer and LED2 wont be activated by the 555 IC3, nor will the op amp IC2 provide a signal.
Consequently, the motorist will be informed of a possible brake problem as long as the red LED is lit and there is no sound or flash.
Formulas:
Use these instructions and familiarize yourself with the following formula to create a Monostable Multivibrator circuit for an Automobile Brake Failure Indicator using a 555 IC:
The pulse duration T formula is:
The following formula provides the output pulses pulse duration T:
T = 1.1 × R × C
where,
- R represents resistor R1s resistance in ohms Ω.
- Cs capacitance is measured in farads F and is denoted by C.
- The 555 intrinsic timing properties are explained by factor 1.1
You may create an efficient automobile brake failure indicator circuit with a monostable multivibrator arrangement and a 555 IC by according to these rules and utilizing the proper component values.
Depending on particular requirements and environmental circumstances, adjustments could be required.
How to Build:
To build a Automobile Brake Failure Indicator Circuit follow the below mentioned steps for connections:
- Gather all the components as mentioned in the above circuit diagram.
- Connect pin Vin of IC1 to +12V brake switch supply through diode D1.
- Connect GND pin OF IC1 to ground.
- Connect Vout pin of IC1 to pin 2 of IC2 trough resistor R2, connect a capacitor C1 to ground from Vout pin of IC1, connect a resistor R1 to ground from Vout pin of IC1.
- Connect a resistor R3 and R4 from positive supply to ground.
- Connect pin 2 of IC2 to Vout pin of IC1.
- Connect connect pin 3 of IC2 between resistor R3 and R4.
- Connect pin 4 of IC2 to ground.
- Connect pin 6 of IC2 to pin 2 of IC3 through capacitor C2, connect from pin 6 of IC2 a resistor R5 and LED1 to ground, connect a capacitor C3 to ground between a resistor R5 and pin 6 of IC2.
- Connect pin 7 of IC2 to positive supply .
- Connect a resistor R6 between capacitor C2 and pin 2 of IC3.
- Connect a resistor R7 and capacitor C4 from positive supply to ground.
- Connect pin 1 of IC3 to ground.
- Connect pin 2 of IC3 to pin 6 of IC2
- Connect pin 3 to ground through resistor R8, LED2, resistor R9 and buzzer.
- Connect pin 4 and pin 8 of IC3 to positive supply.
- Connect pin 5 of IC3 to ground through capacitor C5.
- Connect pin 6 and pin 7 of IC3 between R7 resistor and capacitor C4.
- Connect pin Vin of IC4 to diode D2 and +12V from ignition switch , connect a capacitor C7 from Vin pin of IC4 to ground.
- Connect GND pin of IC4 to ground supply.
- Connect Vout pin of IC4 to the main circuits of IC2 and IC3.
Safety Measures:
- The circuit must be dependable in and of itself.
- A broken circuit might lead to unsafe circumstances by issuing incorrect alerts or not issuing any signals at all.
- Testing, component selection and proper design are essential.
- It is important for drivers to be conscious of this systems limits and realize that its not a perfect solution.
- They should safely pull over and get their brakes checked by a trained mechanic right away if the circuit issues a warning.
Conclusion:
A automobile brake failure indication circuit is a DIY device that alerts drivers to brake problems via lights and a beep.
Nonetheless, expert installation is recommended, and it should not take the place of routine brake maintenance.
Consider it an additional warning mechanism, not a substitute for cautious driving practices.