Abstract:
A vehicle signaling display device to be mounted on an automotive vehicle, so that signaling lights of the device are visible for drivers of following vehicles, includes orange or amber, red and green lights and includes a system specifically designed to count speed sensor pulses for measuring speed of any vehicle of any make and model on which the device is installed, for controlling the signaling lights in accordance with the speed of the vehicle and regardless of operation and position of accelerator pedal of the vehicle, in order to perform a set of standardized operations of the signaling lights for dynamically preventing traffic crashes. The device (a) turns on a distinct arrangement of a number of lights of the signaling lights for indicating different ranges of the speed of the vehicle so that a red light of the signaling lights remains lit without flashing regardless of braking as advanced stop sign indicating very low speed or stationary state of the vehicle, orange lights of the signaling lights remain lit indicating low speed of the vehicle and green lights remain lit indicating forward motion with constant speed; (b) flashes orange lights whenever the speed of the vehicle is reduced by a standardized value without braking; (c) flashes red lights whenever the speed of the vehicle is reduced by the standardized value by braking; (d) flashes green lights to indicate acceleration by the standardized value; so that as the rate of deceleration increases, the red or orange lights flash faster.

Description:
BACKGROUND OF THE INVENTION 
     This invention is a colour coded rear lighting system for motor vehicles. 
     DISCUSSION OF THE RELATED ART 
     There are prior art which try to indicate the rate of the deceleration of a vehicle without relying on mechanical deceleration detectors [U.S. Pat. No. 5,481,243 and GE Pat. No. DE 4236395 A1]. One of the outstanding features of the present invention is that it measures speed of vehicle on which it is installed by internationally standardized unit (eg. km/h) and flashes a light when speed of the vehicle is varied by a standardized speed difference. 
     SUMMARY OF THE INVENTION 
     Dynamic Traffic Light takes the place of centre high mounted stop lamps on motor vehicles, since the brake lighting system presently used on vehicles is too primitive and too static. 
     It is primitive because it has a single and simple function which does not precisely reflect the changes of speed of leading vehicles. If leading driver simply reduces pressing the gas pedal and does not brake at all, speed of his/her vehicle drops. In many cases this decrease in speed has significant consequences but it is not informed to following drivers by any light. Therefore, the brake lighting system currently used in vehicles is not informative enough to following drivers and it is not sufficiently appropriate for a goal so important as to prevent traffic crashes. 
     The brake lighting system which is used at the present time on motor vehicles is static because though it signifies deceleration when driver applies brake, it does not indicate to following drivers how fast the speed of a leading vehicle is reduced. For example, if a car is travelling at certain speed, whether the driver of this car just touches the brake pedal or he/she presses the brake pedal rigorously for swift deceleration, a red light is simply turned on. If leading car is stopped or it has low speed, and its driver is not pressing the brake pedal, there is no indication from a distance to following driver (who may have high speed) that the leading car is actually stopped or it has low speed, unless following vehicle advances perilously closer to leading one. If leading car is stopped with its brake lights on, from a fairly far distance it is not immediately evident to following drivers whether the leading car is stopped or it is in motion. In the latter case, there is no indication about the range of speed of leading car. So following drivers should approach the leading car more and then react. 
     “Lave (1987) ran a number of cross-section regressions on state data. 
     In this invention orange, red and green lights are used to dynamically coordinate the variation of speed of vehicles by providing highway information. At every moment, Dynamic Traffic Light of leading cars help following drivers who just look at the leading cars (on all lanes) from a distance, to realize: 
     a) Whether leading cars travel with a constant speed or they are accelerating or decelerating 
     b) If leading cars are accelerating or decelerating, how fast the speed of these cars is changed. 
     c) The range of speed of leading cars. 
     More precisely, Dynamic Traffic Light performs 12 well-defined functions. In order to explain them, I first define the following: 
     i) One unit of speed=a standardized speed difference or other words, a selected multiple of the internationally standardized unit (eg. km/h). The unit of speed for the operation of Dynamic Traffic Light is selected to be 1 km/h for the occurrence of the first flash of the orange and red lights. The unit of speed is selected to be 3 km/h for the occurrence of the subsequent flashes of the orange and red lights as well as for the occurrence of the flashes of the green light(s). 
     ii) Reference speed=Speed at which a flashing of any light occurs 
     iii) First flash=Flash of orange or red light which occurs after 1 km/h or more is reduced from reference speed. 
     iv) Constant speed=[Mathematically], speed whose domain is: 
     (reference speed−1 km/h, reference speed+3 km/h) so that constant speed can fluctuate in the mentioned domain, and yet no flashing occurs. 
     v) Last flash=Flashing of any light after which speed becomes constant. 
     The frequency at which green, red or orange lights flash help following drivers to immediately perceive how fast the speed of a leading car increases and more importantly, how fast the speed of a leading car decreases. Consequently, following drivers can react more appropriately to the alterations of speed of leading car. 
     It seems that when unit of speed is chosen to be 3 km/h, 10 flashes per second is reasonable as maximum rate of flashing by any light of Dynamic Traffic Light. For example, if a leading driver brakes so hard to reduce the speed of his/her car 30 km/h or more per second, then 10 flashes per second of red light is fast enough to reflect drastic deceleration of leading car. 
     If speed X km/h is increased by Y km/h, so that the Y km/h is less than one unit of speed, green light LG 3  does not flash as it is supposed to, since (X+Y) km/h is still considered as constant speed. If speed (X+Y) km/h is reduced by one unit, red or orange lamps do not flash, because flashing occurs only if one unit of speed is added to or reduced from reference speed. So, in the above example, speed should be first diminished by Y km/h and then it should be further reduced by one unit to cause the first flash of orange or red lights to happen. But the first flash of orange light in particular, is the most important to reduce the reaction time of following drivers. Thus Dynamic Traffic Light is designed so that the first flash of red or orange lights occur as soon as reference speed is reduced by 1 km/h. 
     This assures that the first flash of orange or red lights occur after one unit or less decrease in constant speed. The subsequent flashes of red or orange light occur after at least one unit of speed is reduced from negative reference speed (speed at which a flash of red or orange occurred and continues to decelerate). 
     An extreme case with the functions of Dynamic Traffic Light is when a car equipped with such traffic light loses traction and its tires spin faster than the actual speed of car. This situation is common when a car is accelerated from rest position on snow or ice. The result is false flashes of green light since these flashes are supposed to reflect increase in speed of car. In order to prevent such incorrect flashes, Dynamic Traffic Light is designed so that when speed that is lower than 32 km/h increases, green light does not flash. But if this low speed is reduced, orange or red lights flash. Evidently, false flashes of green light never occur with cars equipped with a traction control system. 
     Accidents occur when speed variations happen. Flashes of Dynamic Traffic Light arise when reference speed is changed at least by one unit. The first flash of orange or red light can be set to occur when reference speed is reduced by 1 km/h or other words, when speed is reduced by 1 km/h or more. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In drawings which illustrate the electronic circuits and wiring of lamps needed to implement the Dynamic Traffic Light, 
     FIG. 1 illustrates front view of one of many possible configurations of lights of Dynamic Traffic Light and the numbering of lights for later references in this description. 
     FIG. 2 illustrates an overall view of this invention. 
     FIGS. 3,  4 ,  5 ,  6 ,  7 ,  8 ,  9 ,  10 ,  11 ,  12  and  13  depict functions of the lights of Dynamic Traffic Light. 
     FIG. 14 illustrates a block diagram of this invention. 
     FIG. 15 illustrates how Dynamic Traffic Light produces a pulse A and a pulse B to indicate one unit decrease and increase in speed of vehicle on which Dynamic Traffic Light is installed. 
     FIG. 16 illustrates a voltage comparator/amplifiers and a speed level determinator which consists of diodes and logical gates. 
     FIG. 17 shows timers needed to drive a number of relays to power the lights. 
     FIGS. 18,  19  and  20  illustrate the relays to power the lights of Dynamic Traffic Light. 
     FIGS. 21 and 22 show a pulse amplifier/transmitter which receives speed sensor pulses of the vehicle. 
     FIG. 23 illustrates a power supply for providing different voltages for different sections of Dynamic Traffic Light. 
     FIG. 24 shows a pulse detector (receiver) which detects pulses sent by the pulse transmitter. 
     FIG. 25 illustrates the connection of lamps of Dynamic Traffic Light. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates front view of one of many possible configurations of the lights of Dynamic Traffic Light and the numbering of lights for later references in this description. 
     FIG. 2 illustrates an overall view of this invention. A multiconductor containing 4 wires connects rear fog light wire, brake light wire, reverse motion light wire, and a ground wire to input P 3 , P 4  and P 5  of Dynamic Traffic Light by 4 pin connectors. A multiconductor containing 9 wires delivers 8 outputs of the relays and a grounded wire from Dynamic Traffic Light to the lamps casing, by using 9 pin connectors. 
     FIG. 3 shows that if the speed of the vehicle is over 31 km/h and under 96 km/h, green lights LG 1  and LG 2  stay on to inform following drivers that leading vehicle has constant speed in the mentioned limits. 
     FIG. 4 shows that if the speed of the vehicle increases, green light LG 3  flashes on momentarily at least per each unit increase in the speed of the vehicle while the green lights LG 1  and LG 2  remain on. 
     FIG. 5 shows that if the speed of the vehicle increases to 96 km/h or more and less than 128 km/h, the green light LG 3  turns on and remain on as the green lights LG 1  and LG 2  are left on to inform the following drivers from a distance, that the leading vehicle has constant speed in the mentioned range. If the constant speed increases, then green light LG 3  flashes off, at least per each unit increase in the speed of the vehicle. 
     FIG. 6 shows that if any speed, that is greater than 31 km/h, is reduced without applying brake on the vehicle, orange lights LO 1 , LO 2  and LO 3  momentarily flash on while all of the green lights which are on flash off, per every unit decrease in the speed of the vehicle. 
     FIG. 7 shows that if the speed of the vehicle is reduced to 31 km/h or less and the brake pedal is not pressed, the orange lights LO 1  and LO 2  stay on (while every other light is turned off) to indicate the low speed of the leading vehicle to the following drivers. 
     FIG. 8 together with FIG. 7 shows that if the vehicle with the low speed decelerates, then the orange lights (LO 1 , LO 2  in FIG. 7) LO 3  in FIG. 8 flash off and on interchangeably, per every unit decrease in the speed of the vehicle. 
     FIG. 9 shows that if the speed of the vehicle is reduced to less than 8 km/h (or if the vehicle is stopped) while driver is pressing the brake pedal, then red lights LR 1 , LR 2 , LR 5  and LR 6  turn on and remain on in the shape of a downward triangle to indicate total stop of the vehicle. Also as a result of this function, if at any speed, a driver has to brake intensely to totally block wheels of his/her vehicle while his/her vehicle is still in motion, then the red lights LR 1 , LR 2 , LR 5  and LR 6  glow as explained. Said red light LR 5  also glows when the speed of the vehicle is under 8 km/h and the brake is not being applied on the vehicle as shown in FIG.  12 . 
     FIG. 10 shows that if the speed of the vehicle is greater than 7 km/h and the brake is applied on the vehicle, the red lights LR 1 , LR 2  immediately turn on. 
     FIGS. 11 and 10 show that if the speed of the vehicle is greater than 7 km/h and the brake is applied on the vehicle, per every unit decrease in the speed, red lights (LR 3 , LR 4  in FIG. 11) and the red lights (LR 1 , LR 2  in FIG. 10) flash on and off interchangeably. So that the faster the speed is reduced, the faster the red lights flash, and the brighter the red light LR 6  glows. 
     FIG. 12 shows that if the speed of the vehicle is reduced to less than 8 km/h and driver of the vehicle is not pressing the brake pedal, the same red light LR 5  of the FIG.  9  and the orange light LO 3  automatically turns on and stays on while the orange lights LO 1 , LO 2  remain on. As a result of this function and the above function described for FIG. 9, when the speed of the vehicle is less than 8 km/h, whether the driver of the vehicle applies the brake on his/her vehicle or not, the red light LR 5  remains on to indicate the very low speed or stationary state of the vehicle. Or to indicate that at any speed a driver totally blocked wheels of his/her vehicle. 
     FIG. 13 shows that if the speed of the vehicle is increased to 128 km/h or more, the green lights LG 1  and LG 2  turn off and only the green light LG 3  remains on to inform the following drivers that the speed of the leading vehicle is constant at 128 km/h or higher. If this constant speed increases, the green light LG 3  and (LG 1 , LG 2 ) flash off and on interchangeably, per every unit increase in the speed FIG.  3  and FIG.  13 . Orange and green lights do not turn on any more as long as the vehicle is set for reverse motion. 
     FIG. 14 illustrates a block diagram of present invention. Dynamic Traffic Light operates by monitoring speed of the rotor shaft in transmission. Rotational speed is monitored by keeping track of fluctuations of frequency of pulses received from speed sensor during predetermined time intervals. After these pulses are amplified, they are transmitted to the receiver in the rear of vehicle where Dynamic Traffic Light is installed. One trivial but inconvenient way of transmission of the mentioned pulses is to extend a wire from transmitter (which is installed near the speedometer) to the receiver in the rear of vehicle. Nevertheless, I have discovered that the two most commonly used microchips, namely NE555 timer and LM339 operational amplifier, can together create a remarkable transmitter and receiver with an astounding transmission rate (more than 19 megahertz). While these transmitter and receiver are highly immune to static, data transmission can be performed through the same twisted wire from which both the transmitter and receiver obtain their power (without change of voltage or current), to a distance of more than 130 m. 
     One unit of speed which represents one unit of frequency is the value of dip switch plus 1 (more about dip switch later). When difference between current speed and the value stored in memory is at least one unit, a flashing of light(s) of a particular color occur, and memory is updated to hold current value of a counter which receives speed sensor pulses of the vehicle from the pulse detector. 
     The value stored in said memory is referred to as reference speed. The value stored in said counter is referred to as the current speed of the vehicle. 
     The counting section counts the pulses received from the pulse detector for a period of time that is determined by timebase. Output of said counter is fed to a comparator  1 , to said memory and to an arithmetic logic unit ALU or subtracter. Outputs of said memory is fed to said comparator  1 , to said ALU and to the speed level determinator. Said comparator  1  realizes whether speed of the vehicle on which Dynamic traffic Light is installed is increasing or decreasing by comparing the current value of said counter (current speed) with a previous value of said counter which is stored in said memory (reference speed). In order to recognize whether the speed has changed by one unit or not, at every moment, outputs of said comparator  1  instructs said ALU to subtract the current value of said counter from the value of said counter stored in said memory or vice versa, which ever generates a positive result. The output of said ALU (which is always a positive binary number) and the value set by dip switch feed a comparator  2 . 
     Decision maker section (gates) receives its inputs from said comparator  1  and said comparator  2 . If, at the end of a time interval, said comparator  2  realizes that the result of subtraction performed by said ALU is at least equal to one unit of the speed then: 
     a) If at the same moment, said comparator  1  is realizing that value of said counter is less than the value latched in said memory, then the decision making section generates the pulse (named pulse A) to indicate that the speed has decreased by one unit. 
     b) If at the same moment said comparator  1  is realizing that value of said counter is greater than the value latched in said memory, the decision maker section generates the pulse (named pulse B) to indicate that the speed has increased by one unit. 
     Only if one of the two mentioned pulses are generated, the decision maker section updates the value stored in said memory to current value of said counter. Other wise, the value stored in said memory (value of said counter at the time that the last pulse A or B was generated) remains unchanged until at the end of a time interval, the value of said counter is at least one unit greater than or less than the value stored in said memory. Whether said pulse A or said pulse B is generated or not, at the end of each time interval said counter is reset to zero so that it begins counting from one for the next sample period. 
     Speed level indicator section obtains its inputs from said memory section. Outputs of said speed level indicator section, which is at 5v VDD voltage level, is amplified to 12v Vcc 1  (of FIG. 21) by voltage amplifier section whose outputs feed transistors and trigger timers to drive their corresponding relays. The latter turns on a specific set of lamps in order to put in effect the appropriate flashing of lamps and the levels of speed shown in FIG. 4 to FIG.  14 . 
     Latch section makes sure that the first flash of red or orange lamps occurs after at most one unit reduction in the speed. If at the end of first time interval during (in the duration of decrease in the speed) the decision maker section realizes that number of pulses counted by said counter is less than the value stored in said memory (regardless of whether this difference is one unit or not), then the decision maker section activates the latch. The out put of latch generates a pulse similar to said pulse A which is amplified to close relays corresponding to red or orange lights. This assures that as soon as the speed is reduced by 1 km/h (ie: as soon as the difference between value of said counter and the value stored in said memory is one), first flashing of orange or red lights arise. The latch is reset only when at the end of a time interval said comparator  1  realizes that the value represented by said counter is greater than the latched value of said counter (ie: when the current speed is increased to greater than the reference speed). 
     Since the greatest binary number that 8 bits can represent is 255, maximum 255 km/h can be monitored by 8 bits, when the unit of speed is y, dip switch is set to (y−1), and time base is 10 Hz. 
     FIG. 15 is the heart of this invention. It produces said pulse A and said pulse B to indicate one unit decrease or increase in the speed respectively. Pin  10  of IC 1  which is a 4040 12 stage binary counter is fed by out put pin  2  of pulse receiver IC 23 -a of FIG.  24 . Said counter counts the incoming pulses from the pulse receiver (IC 23 -a) during time intervals of 0.1 s. Only the first 8 least significant bits of this counter are needed. The 60 Hz signal is generated by IC 12 , an MM5369 17, stage programmable oscillator/divider and its support components. Here said IC 12  uses a 3.58 Hz color burst crystal to produce a stable and accurate 60 Hz reference. IC 13  consists of one 14556 which contains three independent function block. This IC is used here as a divide by 10 counter to generate 10 Hz time base. 
     The output of said divider IC 13  is fed to three pulse generators consisting of: IC 9 -a, C 1  and R 1 ; IC 9 -b, C 2  and R 2 ; and IC 10 -a, C 3  and R 3 . The pulse generators produce three sequential pulses respectively: a so named decision pulse, an update pulse and a clear pulse. Said counter feeds IC 2  an 8 bit magnitude comparator, IC 3  an 8 bit transparent latch (or said memory), and (IC 4  and IC 5 ) two 4 bit arithmetic logic units cascaded to form an 8 bit ALU which is used as said subtracter. 
     Whether value of said counter should be reduced from the value latched by said IC 3  or vice versa (to recognize one unit change in the speed) is determined by select inputs pin  5 ,  6  and  7  of said IC 4 -IC 5 . Pin  7  of said ALUs are grounded. When the current value of said counter is greater than the previous value of said counter which is latched, pin  1  of said IC 2  (an 8 bit magnitude comparator) is pulled low. This low creates a high at out put pin  3  of IC 8 -a (NAND gate) which together with high at output pin  19  of said IC 2  pull low the out put at pin  8  of IC 8 -c. The latter creates a high at output pin  11  of IC 8 -d which in turn sends a high voltage to select input pin  6  of said IC 4 -IC 5 . At the same time, the low output at pin  1  of said IC 2  feeds select input pin  5  of said ALUs. So the value latched by said IC 3  is reduced from the current value of said counter. 
     When the value latched by said IC 3  is greater than the current value of said counter, both outputs pin  1  and pin  19  of said IC 2  go high. And this time, the chain of the outputs of said IC 8 -a, said IC 8 -c and said IC 8 -d create a low at pin  6  of said ALUs while high voltage at pin  1  of said IC 2  feeds pin  5  of said ALUs. Therefore, current value of said counter is reduced from the value latched by said IC 3 . Out puts of said IC 2  are never pulled low simultaneously. The result of subtraction, which is always a positive binary number, is fed to IC 6  (a magnitude comparator). The latter receives 4 least significant bits of its second set of 8 bits input from dip switch, and the other 4 most significant bits are grounded. Only 4 bits are sufficient to represent a value large enough as one unit of speed set by dip switch. 
     When, at the end of a time interval, said decision pulse (output pin  1  of said IC 9 -a) pulls low input pin  2  and pin  4  of IC 7 -a and IC 7 -b (two OR gates) respectively, either input pin  1  of said IC 7 -a or input pin  5  of said IC 7 -b is already pulled low. Simultaneously, if the results of subtraction is greater than the value set by dip switch (ie: greater than or equal to one unit of speed), then both outputs pin  1  and pin  19  of said IC 6  are high. These high voltages at inputs pin  4  and pin  5  of IC 8 -b pull low input at pin  11  of IC 9 -d, at pin  10  of IC 7 -c and at pin  12  of IC 7 -d. The result is that, depending to whether pin  1  of said IC 7 -a or pin  5  of said IC 7 -b is pulled low, either said pulse A is generated at output pin  8  of said IC 7 -c or said pulse B is generated at output pin  11  of said IC 7 -d. Only if said pulse A or said pulse B is generated, the update pulse (output pin  4  of said IC 9 -b) updates said IC 3  (the latch). Whether said pulse A or said pulse B is generated or not, at the end of every time interval said counter is reset by said clear pulse (output pin  6  of IC 10 -b). 
     IC 11 -a together with IC 11 -b (NAND gates) form an RS latch. If the speed is reduced so that number of pulses counted during a time interval is at least one less than the latched value of said counter (at outputs of said IC 3 ), then the decision pulse (at pin  1  of said IC 9 -a) pulls low output pin  3  of said IC 7 -a which in turn pulls low input pin  1  of said IC 11 -a while input pin  5  of said IC 11 -b remains high. This latches output Q of the RS latch (pin  3  of said IC 11 -a) at high state. This high is fed to a pulse generator consisting of IC 11 -c, IC 11 -d, IC 6 -b, C 4  and R 4 . The generated high pulse pulls low (r 1 ) output pin  13  of IC 16 -d. The effect is as said pulse A was generated. 
     FIG. 16 illustrates a voltage divider which generates a 2.5 volts reference by dropping the regulated supply voltage (VDD) across two identical resistors R 21  and R 22 , filtering it and feeding it to eight op-amps configured as voltage comparators/amplifiers. FIG. 16 also illustrates the speed level determinator which consists of a set of eight diodes (D 1 -D 8 ), three gates (IC 10 -c, IC 10 -d and IC 9 -c) and voltage comparators/amplifiers (IC 15 -a, IC 15 -b, IC 15 -c and IC 15 -d). Voltage comparator/amplifiers (IC 16 -c and said IC 16 -d) amplify the pulse A and the pulse B. Outputs of the circuitry in FIG. 16 are used to drive a number of relays for powering the lights. 
     Said speed level determinator obtains its inputs from said memory (IC 3 ). When one unit of speed is chosen to be 3 km/h and dip switch is set to binary number 2, each pulse represents 1 km/h of the speed of the vehicle. Hence, the binary number latched at outputs of said IC 3  is in fact, the speed of the vehicle. The outputs of said speed level determinator, which is at said VDD level, is amplified to Vcc level by the voltage comparator/amplifier section, whose outputs trigger timers in FIG. 17 to drive relays in FIGS. 19-20. The relays turn on a specific set of lamps in order to put in effect the appropriate flashing of the lights and the levels of the speed shown in FIGS. 3-13. Since few lamps in FIG. 25 may get voltage or ground from the same relay in FIGS. 19-20, and since few relays may operate at the same time, few lamps may get voltage or ground simultaneously. But only a specific set of lights should obtain both VCC and ground connections concurrently to implement a unique function at one time. 
     As long as relays are not activated, the green lights LG 1 , LG 2  and LG 3  receive 12v voltage Vcc 4  from output  6  of relay  3  in FIG. 20, and output  9  of relay  2  in FIG. 20 provides ground for the green lights LG 1  and LG 2 . So only these two lights glow to indicates the speed higher than 31 km/h but lower than 96 km/h as shown in FIG.  3 . 
     When the speed increases and said pulse B is generated, output (G 1 ) pin  14  of said IC 16 -c is pulled low to pull low inputs pin  6  and  8  of dual timer IC 18  in FIG. 17 to generate a pulse (G 2 ) at output pin  9  of said timer IC 18  and pulse (G 6 ) at output pin  5  of said timer IC 18 . Said pulse (G 2 ) activates relay  1  in FIG. 19 during a time determined by R 24  and C 12 , to provide output  3  of said relay  1  for the green light LG 3  in FIG. 25, and to flash on this light. This indicates one unit increase in the speed. 
     Said IC 10 -c, said IC 10 -d and said IC 9 -c together recognize binary number that is equal to or greater than decimal number 96. That is, when the speed is greater than 95 km/h, input at pin  11  of comparator said IC 15 -d is pulled low to pull low pulse (G 3 ) at pin  13  of this IC for generating a pulse (G 4 ) at output pin  9  of dual timer IC 19  in FIG. 17 which energizes said relay  1  for providing ground connection ( 3 ) of said relay  1  in FIG. 19 for keeping the green light LG 3  in FIG. 25 on while the green lights LG 1  and LG 2  remain on and the speed is greater than 95 km/h. 
     When the speed (that is greater than 95 km/h) increases by one unit and said pulse B is generated, said pulse (G 6 ) is fed through D 14  in FIG. 17 to pin  8  of said timer IC 19  to pull low said pulse (G 4 ) to release said relay  1  and flash off the green light LG 3 . Since said pulse (G 2 ) should not close said relay  1  when said pulse (G 4 ) momentarily releases said relay  1  to flash off the green light LG 3 , said pulse (G 4 ) disables said pulse (G 2 ) by feeding pin  8  of said timer IC 18  through diode D 13 . 
     If the speed is greater than 127 km/h, pin  19  of said IC 3  (FIG. 16) pulls low (G 5 ) output pin  14  of said comparator IC 15 -c which drives transistor Q 3  to activate said relay  2  as shown in FIG.  20 . Consequently, said output  9  of said relay  2  (ground connection) is disconnected from the green lights LG 1  and LG 2  to turn off these lamps. This result in energizing only the green light LG 3  by said relay  1  to indicate that the speed is 127 km/h or higher as shown in FIG.  13 . If this high speed increases at least by one unit, said pulse (G 6 ) pulls low said pulse (G 5 ). As a result, said relay  2  is momentarily released by said transistor Q 3  in FIG. 20, while said pulse (G 4 ) is pulled low by said pulse (G 6 ) to release said relay  1 . While said output  9  of said relay  2  provides ground connection for the green lights LG 1  and LG 2  to flash on these lights, said output  3  of said relay  1  is disconnected to flash off the green light LG 3 . The result is that per each unit increase in the speed which is greater than 127 km/h, the green light LG 3  flashes off during a time determined by R 23  and C 10  while the green lights LG 1  and LG 2  flash on during the same time, as shown in FIGS. 3 and 13. 
     When the speed is decreased and said pulse A is generated, said pulse (r 1 ) is pulled low to pull low input pin  6  of said timer IC 19 . This generates a pulse (r 2 ) at output pin  5  of said timer IC 19  in FIG.  17 . Said pulse (r 1 ) also pulls low input pin  6  and pin  8  of dual timer IC 20  in FIG. 17 to trigger both timers of said timer IC 20  in order to generate a pulse (O 1 ) at output pin  9  and a pulse (O 2 ) at output pin  5  of said timer IC 20 . At this time, there are two possibilities: 
     a) If the brake is not applied, output voltage (r 4 ) FIG. 18 remains low and relay  4  remains inactivated. Hence, output (r 5 ) of said relay  4  is fed through R 34  to pin  6  of said timer IC 19  to prevent this timer from producing said pulse (r 2 ) at output pin  5  of said timer ICl 9  which would energize said relay  1  for disconnecting ground  5  from the orange light LO 3 . Said pulse (O 1 ) activates said relay  3  during a time determined by R 31  and C 18 . Said output  2  of said relay  3  provides said Vcc 4  for the orange lights LO 1  and LO 2 . Concurrently, said pulse (O 2 ) activates said relay  2  (during a time determined by R 30  and C 16 ) to disconnect said output  9  of said relay  2  (ground connection) from the green lights LG 1  and LG 2 . With said relay  2  activated, said output  9  of said relay  2  provides said Vcc 4  for the orange light LO 3 , and output  5  of the inactive said relay  1  provides ground for the orange light LO 3 . 
     Said pulse (O 1 ) also feeds pin  8  of said IC 19  to pull low said pulse (G 4 ) at output pin  9  of said IC 19  in order to release said relay  1  for disconnecting said output ( 3 ) of said relay  1  (ground connection) from the green light LG 3  to flash off this light when said orange lights flash on. Hence, when the speed is reduced without the brake pedal being pressed, every time said pulse A is generated, all of the green lights flash off and all of the orange lights flash on. 
     When the speed is under 32 km/h, the following happen: 
     i) Input pin  5  of said IC 15 -a is pulled low (by pin  4  of IC 14 ) in order to pull low pulse (O 3 ) at output pin  2  of the IC 15 -a for driving transistor Q 4  which activates said relay  3 , in order to disconnect said output  6  of said relay  3  and turn off all of the green lights LG 1 , LG 2  and LG 3  in FIG.  25 . Output  2  of said relay  3  provides said Vcc 4  for the orange lights LO 1  and LO 2  in FIG. 25 which always have ground connection  1  in FIG.  25 . Thus when the speed is under 32 km/h and the brake is not applied on the vehicle, the orange lights LO 1  and LO 2  remain on while all other lights are turned off as shown in FIG.  7 . 
     ii) When the speed is reduced at least by one predetermined unit and said pulse A is generated, said pulse (O 2 ) activates said relay  2  in FIG.  20 . Said output  9  of said relay  2  provides said Vcc 4  for the orange light LO 3 , and said output  5  of said relay  1  grounds the orange light LO 3  to flash on this light. 
     iii) Said pulse (O 2 ) is fed to input pin  5  of the IC 15 -a to momentarily pull low said pulse (O 3 ) (which momentarily release said relay  3 ) to flash off the orange lights LO 1  and LO 2  while the orange light LO 3  flashes on. Thus when the speed that is under 32 km/h is reduced at least by one unit while the brake is not being applied on the vehicle, the orange light (LO 3 ) and the orange lights (LO 1 , LO 2 ) flash on and off interchangeably as shown in FIGS. 8 and 7. 
     iv) Pulse (O 4 ) at output pin  2  of IC 16 -a feeds input pin  8  of said timer IC 20  to prevent this timer from generating said pulse (O 1 ) when the speed is under 32 km/h and said pulse A is generated. So that said pulse (O 1 ) does not activate said relay  3  to allow flashing off the orange lights LO 1  and LO 2  when said pulse A results in generating said pulse (O 3 ). Said pulse (O 4 ) also prevents production of said pulse (G 2 ) to prevent flashing of said pulse (G 2 ), to prevent the green lights from flashing when the speed is under 32 km/h. 
     b) If the brake is applied the following happen: 
     i) Said relay  4  is activated by said output voltage (r 4 ) FIG. 18 for disconnecting said voltage Vcc 4  from inputs of said relays  2  and said relay  3  which provide said voltage Vcc 4  for the orange and green lights in FIG.  25 . Also with said relay  4  in energized condition, said output (r 5 ) of said relay  4  prevents creation of said pulse (r 2 ). Instead, output  4  of said relay  4  provides said Vcc 4  for the red lights LR 1  and LR 2  while they are grounded by said output  5  of said relay  1 . 
     ii) Said output (r 5 ) of said relay  4  is pulled low in order to let input pin  6  of said timer IC 19  to be pulled low by said pulse (r 1 ), for producing said pulse (r 2 ). Said pulse (r 2 ) energizes said relay  1  for providing said ground connection ( 3 ) for the red lights LR 3  and LR 4  which receive said output voltage ( 8 ) in FIG.  18 . 
     iii) Output K FIG. 18 is fed through D 17  and D 18  to pin  8  of said timer IC 19  and said timer IC 20 , to prevent these timers from generating said pulses (G 4 ) and (O 1 ). 
     With the absence of said pulse (G 4 ), said pulse (r 2 ), which lasts for a period of time determined by R 26  and C 14 , activates said relay  1  to disconnect said output  5  of this relay from the red lights LR 1  and LR 2 , and to provide said output  3  of said relay  1  for the red lights LR 3 , LR 4  and LR 6 . Since said pulse (r 2 ) can be generated up to ten times per second, said pulse (r 2 ) should not last long. As a result, said relay  1  is not closed long enough to turn on a 12 volts light brightly. So 8 v lamps should be chosen or the red lights LR 3  and LR 4 , and 12 v lamps should be chosen for the red light LR 6 . Therefore while the red lights LR 3  and LR 4  glow brightly for the time that said pulse r 2  lasts, the red light LR 6  does not shine adequately during the same time. Consequently, as the speed is reduced faster, the red light LR 6  glows brighter. 
     If the speed is under 8 km/h (and the brake is applied), in addition to the red lights LR 1  and LR 2  which get said output  4  of said relay  4 , the red lights LR 5  and LR 6  also turn on since these lights are provided said output voltage ( 8 ) in FIG. 18, and they are grounded by said output  7  of relay  5 . As a result, the red lights LR 1 , LR 2 , LR 5  and LR 6  remain on. 
     When the speed is less than 8 km/h, output pin  6 ,  7  and  8  of said IC 14  are pulled low by said IC 3  to pull low (r 3 ), output pin  1  of the IC 15 -b. Said pulse (r 3 ) drives transistor Q 5  which energizes said relay  5  in FIG.  20 . Output  7  of said relay  5  provides ground connection for the red lights LR 5  and LR 6  in FIG.  25 . Even when the brake is not applied and said output ( 8 ) of FIG. 18 is low, the red light LR 5  gains said voltage Vcc 4  from output  2  of said relay  3  (which is activated by said pulse (O 3 ) at output pin  2  of the IC 15 -a). Therefore, when the speed is under 8 km/h, regardless of braking the red light LR 5  remains on as depicted in FIGS. 9 and 12. When the brake is not applied and the speed is under 8 km/h, in addition to the red light LR 5 , the orange lights LO 1 , LO 2 , LO 3  also remain on as shown in FIG.  9 . 
     When vehicle is set for reverse motion, only input P 5 FIG. 18 is high. As a result, said output voltage (r 4 ) FIG. 18 has the same effects as mentioned before, and outputs (K) and ( 8 ) FIG. 18 remain low. Thus all lights of the three colors turn off. Only when the brake is applied, red lights turn on as before. 
     FIG. 17 illustrates a set of eight diodes (D 12 -D 19 ) and the timers (said timer IC 18 , said timer IC 19  and said timer IC 20 ) for energizing the relays needed to power the lights as explained. 
     FIG. 18 shows that P 4  input from the brake light wire, and P 5  input from rear motion light wire are directed to affect circuits in FIGS. 18-20 to control the relays as explained. 
     FIG. 19 shows said relay  1  that is energized by said outputs (G 2 ), (G 4 ) and (r 2 ) of the circuitry in FIG.  17 . Said pulse (G 2 ) activates said relay  1  during a time determined by R 24  and C 12 , to provide said output  3  of this relay for the green light LG 3 , and to flash on this light. This indicates one unit increase in the speed. The timer of said timer IC 19  which has pin  9  as output is used as an inverter whose output (G 4 ) can easily close said relay  1  for disconnecting ground  5  from the orange light LO 3  and for providing ground  3  for the green light LG 3  when the speed is greater than 95 km/h as explained. 
     FIG. 20 shows said transistors (Q 3 , Q 4  and Q 5 ) which are derived by said pulses (r 3 ), (G 5 ) of FIG.  16  and said pulse (G 6 ) of FIG. 17 in order to derive said relay  2 , said relay  3  and said relay  5  for controlling the lights as explained. 
     FIG. 21 represents the power supply that obtains its P 1  input from fog light fuse or from the wire from which electricity flows through fog light fuse, to power said pulse amplifier/transmitter in FIG.  22 . 
     FIG. 22 illustrates the pulse amplifier/transmitter which consists of transistors (Q 1  and Q 2 ), a number of resistors and capacitors and IC 21  an NE555 timer. A wire can be branched out from the wire which carries the speed sensor pulses to the speedometer, to provide P 2  input for the circuit in FIG. 22 which is installed near the fuse box. 
     The speed sensor can be connected to P 2  input of said pulse amplifier/transmitter, via a twisted pair cable and a 0.1″ female Molex connector. One side of the sensor is AC coupled to ground through C 22  and C 23  capacitors and the other side is passed on to the input amplifier, which is composed of said transistors Q 1 , Q 2  and associated bias resistor. The speed sensor voltage is biased slightly positive to ensure that said Q 1  turns on reliably. 
     The amplified signals are then sent to input Pin  2  of a 555 timer said IC 21 , which operates as a pulse transmitter. The 555 timer does not feature a capacitor and therefore it is not set in a stable or monostable mode (as a timer). The timer would equally function as a transmitter if it was set in its monostable mode instead of the configuration shown in FIG.  22 . In general, for high data transmission rates, a transmitter with no capacitor is more appropriate. 
     The pulse transmitter transmits the amplified pulses through fog light fuse (ie: through P 1  input of its power supply FIG. 21) to the pulse detector (in the rear of the vehicle) which also gets its 12v voltage Vcc 2  from fog light wire P 3  input, FIG.  23 . There are, however, restrictions for pulse transmission with this method: 
     i) Vcc 1  which is branched off from fog light wire to power amplifier and transmitter at the beginning of line of electricity should not be filtered and should directly or through a rectifier diode power the mention circuit. 
     ii) The voltage which is branched off from fog light wire to power the pulse detector (receiver) at the end of line of electricity should not be filtered and should directly (or only through a protection resistor ˜270 Ω and/or a rectifier diode) power the pulse detector. 
     iii) The voltage mentioned in ii must traverse through a wire (approximately 5 m or longer and could be in the from of a coil) to power circuits other than the pulse detector which like the pulse detector obtain their power further from the beginning of line. In Dynamic Traffic Light the pulse detector obtains its power only through protection resistor R 44  and other circuits get their power through a coil FIG.  23 . 
     iv) Diode D 45  must isolate the power supply which generates 12v voltage Vcc 3  and the voltage VDD as shown in FIG. 23, to prevent the line of electricity (and said Vcc 2 ) from being filtered. 
     FIG. 23 represents a power supply that obtains its P 3  input from rear fog light wire, and generates said Vcc 2  for powering the pulse detector, said Vcc 3  for powering the timers, transistors and relays, said Vcc 4  for powering the lights through said relay  4  in FIG.  20  and VDD for powering the components in FIG.  15  and creating the voltage reference in FIG.  16 . 
     FIG. 24 shows the pulse detector (receiver) said IC 23 -a whose output is fed to the said counter (IC 1 ) in FIG.  15 . The pulse detector is one of the comparator of LM339 (quad comparator), and is set as a non-inverting voltage comparator. 
     FIG. 25 illustrates the wiring of lamps installed in lamps casing of Dynamic Traffic Light. Since each relay may provide electricity for lamps of different lights, diodes D 47  to D 52  allow only a specific set of lamps (shown in FIG. 3 to FIG. 13) to be turned on at a time. 
     More about unit of speed: 
     A speed sensor which generates at least 20 pulses per revolution of rotor shaft in transmission can be used with this invention; such as 20 pole magnetic resistance element sensors (MRE) and photo coupler sensors. Such sensors assure the production of at least one pulses per time intervals of 0.1 s at 1 km/h of speed, in order to monitor the change of speed satisfactorily. Hence, an appropriate speed sensor which generates an appropriate number of pulses per rotation of rotor shaft should be used. 
     In order to set the dip switch, we first define the following variables: 
     n=value set by dip switch which is number of pulses received from sensor during each 0.1 s at ((a selected multiple of unit of speed km/h)−1)km/h. 
     p=number of pulses that speed sensor generates per rotation of rotor shaft in transmission. 
     u=the selected multiple of unit of speed (which is an standardized speed difference) such as 1 km/h or 3 km/h. 
     I select u=3 km/h as a value representing a standardized speed difference. 
     t S =transmission revolution per 0.1 s 
     d=differential ratio of a car 
     r=radius of wheel (wheel size) 
     t=transmission rpm 
     c=2πr circumference of wheel 
     w=wheel revolutions per minute 
     And from mechanics: w=t/d and (u) speed=w * c═&gt;w=u/c 
     We want c per centimeter as we have speed per km/h. But since radius of wheel is normally given per inch, we change r to cm: 
     c=2πr″ inch * (2.54 cm)/(1 inch)=5.08πr″ cm 
     We defined u=3 km/h. But we want u as centimeter per minute 
     →u=3 km/h * 1000 m/km * 100 cm/1 m * 1 h/60 min=5000 cm/min 
     W=u/c=(5000 cm/min)/(5.08πr″ cm)=(313.3/r″) wheel revolution per minute at 3 km/h 
     Also w=t/d→t=w * d Replacing w→t=(313.3 * d)/r″ 
     t S =t * (1 min)/(60 sec) * (1 sec)/(10)=t/600 and n=(t S * p)→n=(t/600 * 20) 
     →n=t30 Replacing t with (313.3* d)/r″ →n=(313.3 * d)/(30 * r″) 
     →n=(10.44 * d)/r″ 
     Therefore, if for example wheels of a car have radius 15″ and differential ratio of that car is 3.5, then assuming that the speed sensor of this car generates 20 pulses per revolution of rotor shaft: 
     →n=(10.44 * 3.5)/3.5→n=2.4 
     We round the 2.4 to 2 in order to set the dip switch. Therefore, a flash of a light occurs when the result of subtraction is &gt;2. 
     The value obtained for dip switch is almost always is a real number. And since we round the number to an integer, the flashing of lamps do not show exactly 3 km/h increase or decrease in speed. Since differential ratio and wheel size are not the same in all cars, each pulse during the same time interval of 0.1 s does not represent the same speed in different cars. Referring to the formula that we obtained for variable n to set the dip switch, the calculation of value of dip switch depends to the variables d, r, and p. 
     Besides choosing the right speed sensor, car manufacturers who would like to install Dynamic Traffic Light on their cars, may make some adjustment on wheel size (r) and/or on differential ratio (d) to make sure that when different cars travel at the same speed, speed sensor of these cars generates the same number of pulses per each time interval. This also assures that flashing of lamps occur when speed of any vehicle varies by a standard unit of speed (3 km/h). If wheel size is easier to be changed then its adjustments should be done as follows: Since we want the speed sensor to generate at least one pulse per 0.1 second, we consider n a number that is equal to or greater than zero. For example if we choose n=2 (and we set dip switch to 2) when unit of speed is 3 km/h, then 2=(10.44*d)/r″ And the differential ratio (d) of each car is known. So we can obtain a value for r: r=(10.44*d)/2 
     EXAMPLE 1 
     If differential ratio of a car is 3.5 to 1, then r should be: r=(10.44*3.5)/2=18.27″ Therefore, for a car with differential ratio of 3.5, wheel of size 18.27″ will result in one flash per exactly every 3.0 km/h increase or decrease in speed, if dip switch is set to 2. So we can maintain an standard unit of speed for flashing a lamp of Dynamic Traffic Light and for displaying speed levels. Similarly the differential ratio can be adjusted in accordance with a selected value for the wheel size and for variable n. Alternatively, variable P can be adjusted based on a fixed value for the differential ratio (d), wheel size (r) and variable n. 
     
       
         
               
             
               
               
             
               
             
               
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
               
             
           
               
                   
               
               
                 PARTS LIST 
               
               
                   
               
             
             
               
                 All resistor are ¼-watt, 5% 
               
             
          
           
               
                 R1-R4, R35, R42 — 2200 ohms 
                 R34 — 22,000 ohms 
               
               
                 R5 — 22 megohms 
                 R40 — 33,000 ohms 
               
               
                 R6, R25, R29, R32 — 100,000 ohms 
                 R43 — 470 ohms 
               
               
                 R7-R11, R20, R28, R38 — 10,000 ohms 
                 R44 — 270 ohms 
               
               
                 R12-R17 — 12,000 ohms 
                 R45 — 1 megohms 
               
               
                 R18, R19, R21, R22 — 220,000 ohms 
                 R46 — 12,000 ohms 
               
               
                 R23, R24, R26, 
                 R39, R41 — 1,000 ohms 
               
               
                 R27, R30, R31 — 270,000 ohms 
               
             
          
           
               
                 Capacitors 
               
               
                 Capacitors C20, C23 and C24 are electrolytic, all others are disc 
               
             
          
           
               
                 C1, C4 — 0.001 μF disc 
                 C12 — 0.25 μF disk 
               
               
                 C5 — 22 pF disc 
                 C16, C18 — 0.4 μF disk 
               
               
                 C6 — 33 pF disc 
                 C20 — 10 μF, 16 volts 
               
               
                 C7-C9, C11, C14, 
                 C23 — 4.7 μF, 16 volts 
               
               
                 C15, C17, C19, 
                 C24 — 1,000 μF, 25 v 
               
               
                 C21, C22 — 0.1 μF disc 
                 C25, C26 — 0.01 μF disk 
               
               
                 C10 — 0.3 μF disc 
                 C27 — 100 μF disk 
               
             
          
           
               
                 Semiconductors 
               
             
          
           
               
                 IC1 — SN74HC4040 asynchronous 12-bit binary counter 
               
               
                 IC2, IC5 — SN74HC682N 8-bit magnitude comparators 
               
               
                 IC3 — SN74HC373N octal D-type transparent latch with 3-state output 
               
               
                 IC4, IC5 — SN74LS382AN 4-bit arithmetic logic units 
               
               
                 IC7 — SN74HC32N quadruple 2-input positive-or gates 
               
               
                 IC8, IC10, IC11 — SN74HCOON quadruple 2-input positive-nand gates 
               
               
                 IC9 — SN74HCO2N quadruple 2-input positive-nor gates 
               
               
                 IC12 — MM5369 17-stage oscillator/divider 
               
               
                 IC13 — MC14566B industrial time base generator 
               
               
                 IC14 (D1-D8), IC17 (D12-D19) — TND903 silicon diode arrays 
               
               
                 IC15, IC16, IC23 — LM339N quad comparators 
               
               
                 IC18, IC19, IC20 — NE556N dual timers 
               
               
                 IC21 — NE555N timer 
               
               
                 IC22 — 805 voltage regulator 
               
             
          
           
               
                 DIODES 
               
             
          
           
               
                 D22-D25, D27, D28, D30, D31, D34, D35 — 1N4148 silicon diode 
               
               
                 D25, D29, D32, D33, D36-D39, D41-46 — 1N4004 rectifier diode 
               
               
                 D47-D52 — 1N5339B 
               
             
          
           
               
                 TRANSISTORS 
               
             
          
           
               
                 Q1, Q2 — 2N3904 NPN transistors 
               
               
                 Q3, Q4, Q5 — 2N3906 PNP transistors 
               
             
          
           
               
                 Relays 
               
             
          
           
               
                 Relay 1 . . . Relay 5 — HGSR51111POO 12 volts mercury to mercury, 
               
               
                 form C relays from CP-Clare 
               
               
                 Note: 
               
               
                 Testing was performed by SPDT DS1-M Aromat relays. But in order to 
               
               
                 avoid resonance when relays operate, I introduce the above relays. 
               
             
          
           
               
                 MISCELLANEOUS 
               
             
          
           
               
                 F1, F2 — 1 amp slow blow fuse 
               
               
                 S1 — 4 position dip switch 
               
               
                 XTAL1 — 3.58-MHZ color-burst crystal 
               
               
                 Wrapped wire or coil 5 m long 22 gage 
               
               
                 12 sockets for bayonet lamps 
               
               
                 LG1, LG2, LG3, LO1, LO2, LO3, LR1, LR2, LR5, LR6 — 12 volts 
               
               
                 bayonet lamps 
               
               
                 LR3, LR4 — 8 volts bayonet lamps