科技论文-防盗电话报警控制器电路的设计.doc

科技论文

题 目 The Application of LCD

系 别 尚德光伏学院
专 业 计算机控制技术

2010年 12 月

Burglar telephone alarm controller circuit design
Summary ：

With the continuous development of electronics, applied electronics is steadily moving toward a new era. Electronic technology, electronic design, electronic products, such as the ever-changing update to the people's lives is a big convenience. This paper introduced a confusing phone-based anti-theft controller circuit, if you are away from home, as long as you make a phone call to home, your home will sound tape recorders, dark, the interior lights will be bright. The circuit by the signal input circuit, trigger circuit, driver circuit, light sensors, integrated electronic switch circuit.
The design detail of the anti-theft alarm detection phone part of the whole production process, but also by the content of the design done a kind of success.
Keywords: telephone anti-theft electronic switch
A, design of purpose and meaning
1. Learning basic theory in practice comprehensive use of the initial experience, master the basic methods of electronic circuit design, the design procedure, the ability of training comprehensive design,
2. Through the actual system application and operation, to deepen the understanding of the knowledge,
3. Through the assembly and debugging cultivation of practical skills, improve the analysis and the ability to solve practical problems.
Second, design planning
1, design idea
Confuse anti-theft telephone controller circuit, if you go out in the outside, as long as you to call home, your house will be issued a voice recorder, dark, indoor light will shine. This circuit by power supply circuit, signal input circuit trigger circuit, drive circuit and photosensitive sensors, integrated electronic switch circuit composed.
2, design charts

Third, each part of the circuit design
1 and power circuit design
The direct current voltage-stabilized source structure diagram:

Utility voltage transformer and pass through the fuse IN4007 diode rectifier, lower blood pressure, LM7805 capactance filtering, avr output, use red leds instructions power circuit work condition and power circuit principle as figure2shows.

Figure 2 power circuit
220V utility after transformer T step-down, output voltage, communication about 9V diode (VD1 ~ VD4) bridge rectifier, capacitance C1 filter out the high-frequency clutter after LM7805 feet, 1 to 2 feet grounding, 3 foot stable output voltage, voltage for 9V. C2 further filter high frequency interference, supply circuit work, red issued diode is the power indicator light emitting diode, R1 is the current limiting resistor, light emitting diode current for normal work of 10mA.
Transformer principle is very simple elfevident transformer is main function of variable pressure, also is change voltage. Transformer is principle electromagnetic induction technology, transformer has two independently of sharing a core of coil. Respectively called transformer subprime coil and primary coil. Current direction and size varies with time, transformer primary tong on ac, transformer core created alternating magnetic field, (including connect power of winding called primary coil, the rest of the winding called subprime coil. In the same frequency induction subprime is the ac voltage. The first level of transformer winding of turms than equal voltage than. Transformer can only change ac voltage dc voltage, and do not change, because the direct current is not change, current through the transformer won't produce alternating magnetic field, so only in subprime coil directly connected moment produces a instantaneous electric current and voltage.
LM7805 is three terminal voltage stabilizer fig.03 shows: (1) the feet to the input voltage regulator Ui, 3 feet for the grounding end; 2 feet for voltage stabilizing voltage Uo output terminal. LM7805 have 5V, 6V, 9V, 12V, 18V and 24V 15V, seven different fixed output voltage, which are widely used in various kinds of electronic equipment. Maximum output current for 1.5 mA.
LM7805 stabilizer with internal over-current, thermal overload and output crystal figure 3 LM7805 tube feet body tube safety protection function, circuit used Safe and reliable. Although according to fixed voltage stabilizer which design, but external pick a few components, can make adjustable voltage stabilizer or adjustable stablized implement use.
2, signal input circuit design
When the telephone in hang condition, telephone lines L1, L2 between 40 ~ 60V of dc voltage, due to the capacitance C1,
C2 role, not by integrated circuit IC1 triggered such components delay circuit. When people call scoring comes, L1,
L2 coming signal submitted variable state, ringing the capacitance C! C2 coupling, diodes, VD1, VD2 times pressure rectification, electricity
Let the C3 filtered into a positive dc voltage up to triode V, resulting in the base of V saturated conductivity
3, trigger circuit design
This circuit adopts NE555 time-based circuit as schmidt trigger circuit, triggering high sensitivity and reliability.
Figure 8 is by the time base circuit 555 and RA, RB, RC minority components adjustable threshold voltage Schmitt toggle, visible by comparator drive schmidt trigger circuit, total output has two port: one is 3 feet of rectangular pulse output, A discharge end (DSC) 7 feet discharge waveform (external capacitor).

(a) circuit diagram (b) schmidt trigger characteristics
图8
A separate pressure in the circuit spare some input in RP potentiometer signal for Vin, adjust RP will input signal has a certain range change, according to the trigger reset and 555 buy a characteristics, and its output terminal Vo (3 feet) will has the following changes:
When the input triggered signals Vin (figure 8 - less than VA b), set 2 feet for level low level "0", the six feet also for low level "0", then in a state, buy 555 feet high potential output is 3 "1",
When the VA < Vin < VB, i.e. 2 feet for low level (1/3VDD), 6 foot is still low level (1/3VDD), 3 foot output is still has high potential, this state of bi-stable state;
When Vin > 1/3VDD and Vin > VB (2/3VDD), turn a 555 reset state, that is, 3 foot output to low level "0".
By the above analysis and graph (b) visible, 555 triggered and transmission characteristics, and its rise and decline of the characteristic signal characteristics do not overlap, and the existence of back to poor Δ V, reason this voltage trigger circuit called schmidt circuit.
Back to the poor Δ V size of voltage
Δ V = VB - VA
= = VDD - VDD
= = VDD
Change the ratio of RP and RB, may change the circuit back Δ V. Poor voltage
The main 555 time-based circuit parameters and all tube foot function
In order to correctly use 555 timebased circuit, must understand its one of the parameter value, below, is its parameters (1) 555 time-based circuits using the voltage of power supply in 4.5 ~ 16V range, so this circuit adopts 5V voltage power supply.
Static current is also called work refers to the source current when the consumption of manifold blocks no-load current. At that time, when the yankees integrated blocks on pin connected to the power source voltage: 555 time-based 5V circuit of static current typical values about 10mA.
(2) threshold voltage and current threshold
When added to 555 time-based circuit threshold input that the voltage is equal to or greater than 2/3Vcc (or VDD voltage), work, make its output from the high level into low electricity at ordinary times, voltage 2/3 Vcc namely for its threshold voltage UTH, causing the time base circuit state flip need working current is called threshold current ITH. Various time-based circuit threshold value of current as 0.1 u A left.
(3) timing precision
Timing precision refers to the time base circuit used when used in precision degree of timer. Two time base circuit of the timing precision 1%.
(4) discharge current
555 as timer or more harmonic oscillator when using, used the discharge end to external capacitor a grounding discharge access. By figure 2-1 can see, discharge current needs to pass a discharge tube VTD because of its current to limit, or current had congress to make VTD burn out. The discharge current 555 IDIS in 10 ~ 50mA between, and decreases as the power supply voltage VCC (or VDD) numerical changes, Use the voltage of power supply, the higher the discharge current is greater.
(5) trigger voltages and trigger current
When added to 555 time-based circuit trigger input voltage of less than or equal to 1/3VCC, make its output from the low level into high electricity at ordinary times, voltage value 1/3VCC namely for its trigger voltages UTR. Cause time-based circuit state flip need working current is called trigger current ITR. All the time base of the circuit to 0.5 muon A trigger current.
(6) reset voltage and reset current
When at 555 time-based circuit Lord reset end MR (not) with low level, can make its output reset (namely VO = 0), which I have put UMR reset voltage should be below the 1V. Cause time-based circuit reset need working current is called reset current IMR. Various time-based circuit for 400 mu A reset current to the left.
(7) the highest working frequency
The highest working frequency refers to point circuit is connected into 555 when oscillating circuit when using, the highest frequency output pulse.
(8) drive dc
Drive dc refers to the time base circuit while working for load provides output current, also called load current IL, according to the time base circuit of the output state and load connection, drive current usually divided into pull current with inhaled current two kinds.
555 time-based circuit each tube foot function
One feet: power negative GND terminal
Two feet: low flip-flop, abbreviation trigger end TR non
Three feet: output terminal OUT, can will relay coil etc load attached to it, the other side with power positive or negative connected, its biggest output current is not less than 200MA
Four feet: mandatory reset end, if do not need not MR compulsory reset, and can be connected with power positive or impending
Five feet: used to regulate the comparator's benchmark voltage, abbreviation control terminals Vc, if do not need to adjust the benchmark voltage, it may be suspended or through 0.01 u F, capacitors grounded.
Six feet: high flip-flop, or called threshold end TA
Seven feet: discharge end DIS
Eight feet: connect the power supply, the positive VDD 555 time-based circuit allows supply voltage 450 V ~ 18V
4. Driver output circuit design
For 555 integrated circuit maximum output current 200 ma, so can't reliable direct drive dc relay, reason need to add level 1 transistor amplifier, so the driver output portion composed by the transistor and relays.
This circuit relay models 4098, dc resistance to 300 Ω, drive current for 200 ma, reason transistor collector current should be more than 300 ma set transistor current amplification coefficient for 50, the beta transistor turn-on the base current for 300/50 = 6 (ma). Can be calculated resistance R10 = (6V - 0.7 V) / 6mA hundredth 9K Ω, so this circuit Ω R10 take 10 K, triode can be used for 9013, maximum output current 500 milliampere.
5 and photosensitive sensor
This circuit photosensitive sensor adopts light activated triode 3DU31, it is one of the most common photodetector, its sensitive wavelengths in the visible wavelength near infrared wavelength and ultraviolet ray, including wavelength.
Light activated triode and ordinary triode similar, also have current amplification effect, but it is not just the collector current by passive circuit and current control, but also by ray radiation control. Usually base not derivation, but some light activated triode base have derivations, used for temperature compensation and additional control functions.
When having photosensitive properties of PN junction by irradiation, formation, thus resulting in the light of photo-current born by base into emitter current collector loop, in order to get an enlarged equivalent to beta times the signal current. Different material made of light activated triode have different spectral characteristics and compared with photosensitive diode, has the very big photo-current amplification, namely high sensitivity.
Through to the semiconductor diode and triode learning, I understand the transistor the basic structure and working principle of semiconductor, transistor, is one of the basic components, with current amplification effect, is the core of electronic circuit components. Transistor is in a semiconductor substrate production two are located very close of PN junction, the two PN junction is divided into three parts, block semiconductor middle part is base-combed, two side part is the launch region and integrating electricity area, arrangement have PNP and two NPN transistors, as shown in figure drawn from three areas corresponding electrode, respectively base b emitter e and collector c.
Launch region and base-combed between PN junction that launch knot, combines electronic zone and base-combed between PN junction called the collector. Base-combed is very thin, and launch region thicker, impurity, PNP transistor concentration large type emission region "fire" is the direction of movement, the cavity with current direction, reason emitter to the arrow, NPN transistor launch region "firing type" is free electrons, which the movement direction and current in opposite directions, so emitter arrow outward. Emitter arrow outward. Emitter arrow in also PN junction in forward voltage under the conduction direction. Silicon transistor and germnium transistor have PNP type and NPN type two kinds. Although key learning transistor amplifying function of transistors, but I more interested in the switch function. Semiconductor like a switch, can pass conduction and the due to control circuit.
Semiconductor by adding part of trace element will make its characteristic earth-shaking changes. Photo transistor is a kind of important derivatives. Human body is the most important visual sense, therefore, I think through light to control circuit is really too subtle, and photosensitive diodes triode just can finish this task. Because light activated triode due to still have amplification, therefore application than diode more extensive. Light activated triode is used for measuring brightness, often with light emitting diode is used together as a signal receiving devices. Use examples below introduce various functions.
(1) measurement brightness
In the classroom library, and many times, fluorescent lamp daytime also on, in the dormitory inside, fluorescent lamp is often rest day and night, the students on this waste has insensitive. Some classmates in the morning to go to the classroom, although