Electronique et Eclairage

Electronique et eclairage

                                                        introduction

—At the beginning of the 21st century, we are seeing considerable changes in the information technology sector, both in terms of applications and use and in terms of technology.   We notice the invasion of electronics in several sectors such as:

—The telecommunications sector

—The robotics industry sector.

— The field of flight and space Energy management and comfort

The themes developed cover both studies aimed at improving current technologies, pushing technology to its ultimate limit, and studies that prepare the electronics of tomorrow, with innovative materials and concepts use.

—The proposed schématique is based on the introduction of a timer with a simple illumination; When the light bulb is switched on, a timer goes into operation during the cycle and counts the time of opération, the user control operation time with an adjustable résistance . the timer is equipped with a device Of warning of end of cycle to warn to its user that the lighting of the bulb comes to an end and to avoid the existance in the darkness.

—   Obtaining a continuous power supply from the source

     When the receiver is powered, the low-value resistor R1 is inserted into its supply circuit. If P is the power of the receiver, the effective intensity passing through this resistance is deduced by means of the relation: I = P / 230v     The result is an alternating potential "u" ​​at R1.  This potential is equal to  U (V) = R1 * I (A), or I = P / 230v. In the present case, for a value of R1 = 10 Ω And a power P of value 100 w; U = 4.35v The power "p" released by R1 can be deduced by the relation p = 10 * 100² / 230². This power is equal to 1.9W, we will retain a power resistance of value of 100W

   The importing role of a bridge is rectifying the two alternations of this potential.

     The capacitance C1 performs the filtering. The result is a continuous potential of the order of 4.5v on the positve armature of this capacitance which constitutes the power supply for the assembly. It will be noted that this power supply only exists when the receiver is itself powered. otherwise, the fraction of the potential taken is insignificant: it is indeed less than 2%

—The table opposite shows the values of the power resistance according to the power of the receiver.

—The table opposite shows the values of the power resistance according to the power of the receiver.

c	R1(Ω )	P(W)
75	12	2
100	10	3
150	6,8	3
200	5,1	5
300	3,3	10
400	2,7	10
500	2,2	15

Fonction’s timer

—By pressing the BP push button, the receiver is energized.

—    The result is immediately the appearance of the potential of 4.5v on the positive armature of C1. This capacitor serves to maintain the continuity of the supply to the receiver even when the pushbutton BP is released by means of a counting device IC2 which is a CD4040 integrated circuit having 11 binary stages

Timing

—By pressing the BP push button, the receiver is energized.

—    The result is immediately the appearance of the potential of 4.5v on the positive armature of C1. This capacitor serves to maintain the continuity of the supply to the receiver even when the pushbutton BP is released by means of a counting device IC2 which is a CD4040 integrated circuit having 11 binary stages

—Timing end

The logic levels of the counters evolve according to the principle of binary counting.

The output Q11 of the counter passes at a high level after 2 to the power 11, that is to say 2048 elementary counting slots. The output of the gate U9: C goes low, while the output of the gate U9: D has a high state, which blocks the transistor Q1 of the pnp type. The conduction of the triac in the MOC 2130 circuit is no longer assured and the receiver switches off. The potential 4.5 v disappears gradually due to the discharge of C1.

If the position of the cursor of the adjustable A is placed in the middle the delay is deduced by the following relation: 50 mil * 2048 = 102 seconds, ie 1 minute and 42 seconds

If the cursor is placed at the maximum position the time delay becomes 100 mil * 2048 = 204 seconds,  3 minutes and 24 seconds.

Notice of extinction

The outputs Q6, Q9 and Q10 are connected to the cathode of three diodes D8 to D10 whose common anodes are connected to the "+" of the power supply through the resistor R6.

At the common point of the anodes there is generally a low state.

When these 3 outputs simultaneously present a high state in an instant,

The meter will have advanced 1600 elementary steps calculated as follows

(2 power 10) + (2 power 9) + (2 power 6).

At this point, the common point of the anodes passes to the high state, which causes the start of the monostable flip-flop formed by the NOR gates U9A: and U9B:

The output of the latter then has a short high state of the order of 50 milliseconds

—The transistor Q1 is blocked during this period of time, the light bulb then ceases to be supplied temporarily, but this duration is not low so as not to disappear from the supply of 4.5 V present at C1.

—A brief flashing of the bulb will be observed which will warn the user that the timer is coming to an end.

—In reality the blinking of the bulb starts from 1600 elementary slots up to 2048, or 80% of the time delay.

—From this moment the warning signals occur at the rate of the successive passage of Q6 in the high state, that is to say all 64 counts from 1600 slots.

—If we consider that the slider of the adjustable is in the middle position which corresponds to a period of 50 milliseconds and if Q6 goes high all the 64 elementary periods, it results that the period corresponding to the blinking is deduced by the relationship

— T blink = (elementary period * 64)  50 mil * 64 = 3200 = 3 seconds and 200 milliseconds.

Electronic schema

—The diagram is made using the proteus 7; A software for input of electronic schema including ISIS 7 professional that allows the simulation of the assembly and ARES7 professional that allows the arrangement of the electronic components for the routing and the construction of the typons in order to build the electronic cards "PCB".

Diagram established on ISIS7 professionnel

Circuit diagram printed on ARES

View of PCB in 3D