Most accidents on highways at night happen because drivers can't see well because they are constantly looking into the bright headlights of cars coming toward them. The poor vision is caused by the visual pigment in the eyes running out, which makes the person want to sleep to get the pigment back. This alarm doesn't let you sleep. This circuit keeps you alert by making short beeps and flashing lights to remind you that you are not on a bed but instead driving a car. It only works at night because of a switch that is controlled by a light-dependent resistor (LDR).

Anti-sleep alarm circuit

The light switch is made up of the LDR and two BC548 transistors (T1 and T2). This keeps IC1 from oscillating during the day. During the day, when the LDR is exposed to light, T1 conducts to stop T2 from conducting. This makes pin 12 of IC1 high, which stops it from oscillating. So the rest of the circuit stays in a state called "standby."

At night, T1 doesn't work because the LDR is dark. Pin 12 of IC1's reset pin is pulled to ground when T2 conducts. This makes IC1 start to oscillate, which is shown by the flashing of LED1. The values of R5, R6, and C1 determine how fast the oscillator inside the binary counter IC CD4060 goes around and around. Its Q13 output goes from high to low and back again every 15 minutes. With the potmeter VR1, you can change how sensitive the LDR is. How a circuit works When the Q13 output of IC1 goes high, the reset pin (pin 4) of NE555 astable (IC2) goes high, and it starts to oscillate. Depending on how R10, R11, VR2, and C2 are set, there will be one pulse every 50 seconds. Using VR2, you can change the pulse rate just a little. IC2's pulsed output is connected to IC CD4017's clock input (IC3). A decade counter, like IC CD4017, has ten outputs, but only one of them is high at any given time. The other nine outputs stay low. IC3 uses the output from IC2 as its clock. So, the Q1 output of IC3 goes high when IC2 goes high for the first time after 50 seconds. After 6 minutes, Q6's output goes high, LED2 lights up for a minute, and the alarm buzzer goes off. If the circuit isn't reset using the push-to-switch S1 after hearing the warning beep from PZ1, IC3 keeps counting, and at the end of 10 minutes, the Q9 output goes high to turn on IC CD4093 (IC4). Circuit construction With its two NAND gates 3 and 4, IC4 is set up as a simple oscillator. Gate 1 of IC4 is controlled by how pins 1 and 2 are wired. When IC3 sends a high signal to these pins, the signal from gate 1 goes low and the signal from gate 2 goes high. This turns on the oscillator, which is made up of gates 3 and 4. The rate of oscillation depends on what R13 and C3 are set to. As long as IC3's Q9 output stays high, which is for 15 minutes, IC4 oscillates and the piezobuzzer beeps and the white LEDs flash at a rate set by the values of R13 and C3. After that, IC4 stops oscillating, and the piezobuzzer and LEDs turn off for another 15 minutes. Every 15 minutes, the cycle starts again. This is enough to wake up the driver who fell asleep. The 12V DC power for the circuit comes from IC5 and C4.

The circuit can be built on a board with holes in it and powered by the car's battery. The unit should be put in front of the driver's seat, on the dashboard if possible. Keep LDR1 away from LEDs at night so it can go to sleep. The power for the circuit should come from the car's ignition switch, so that it only works when the car is moving.