The article basically is about 3 end manostat is mixed the relevant introduction of stabilized voltage diode, emphasize pair of stabilized voltage diode 3 end manostat and undertook be elaboratinged in detail.

 

3 end manostat
 

Canal of 3 upright stabilized voltage is a kind till the semiconductor device that very tall resistance has before voltage of critical and retrorse puncture. Stabilized voltage canal is when retrorse puncture, inside certain voltaic limits (perhaps say to be inside limits of certain power loss) , upright tension is almost constant, show stabilized voltage character, apply extensively at consequently regulated power supply and be restricted a circuit in.

 

 

 

Because secure 3 end,manostat belongs to circuit of series connection stabilized voltage, because its principle is equal at circuit of series connection stabilized voltage.

 

Among them the voltage divider that R1, Rp, R2 comprises is sampling circuit, from output end takes out partial voltage UB2 to be added to the base of dynatron T2 as sampling voltage. Stabilized voltage is in charge of Dz to stabilize voltage Uz to serve as fiducial voltage with its, be added in T2 blast off extremely on. R3 is the current limliting resistance that stabilized voltage provides. Dynatron T2 composition compares enlarge circuit, it tries sampling voltage UB2 and fiducial voltage Uz to compare and magnify, go controlling the base potential of dynatron T1 again. Input voltage Ui is added on dynatron T1 and the circuit that laden RL photograph establishs ties, accordingly, the voltage drop UCE1 between change T1 collector the voltage Uo of two end of adjustable RL. That is to say, the output voltage Uo of stabilized voltage circuit can try to adjust through dynatron T1, so T1 is called adjust a canal. Because adjust component,be transistor canal, and establish ties with laden photograph in circuit, reason calls circuitry of transistor series connection stabilized voltage. The base of resistor R4 and T1 slants buy resistor, also be the collector load resistor of T2.

 

When be reduced when voltage of electrified wire netting or making output carries voltage to drop somewhat, UB2 of its sampling voltage is reduced accordingly, t2 base potential drops. But because T2 blasts off extremely potential already the stable Uz that stabilized voltage is in charge of keeps changeless, blast off so extremely voltage UBE2 is reduced, bring about T2 collector electric current is reduced and collector potential Uc2 lifts. Because magnify the collector that runs T2 and the base that adjust tubal T1 are received together, potential of reason T1 base is elevatory, bring about collector electric current to increase and tubal pressing falls UCE1 is reduced. Because T1 and RL establish ties, so, output voltage Uo is basic and changeless.

 

Manage together, when voltage of electrified wire netting or load produce change to cause output voltage Uo to increase, through sampling, magnify quite, adjust wait for a process, will make adjust the canal that adjusts a canal to press fall UCE1 increases, the result restrained output to carry the accretion of voltage, output voltage still keeps basically changeless.

 

Adjust potentiometer Rp, can undertake fine tuning to outputting voltage. Adjusting those who be in charge of T1 and composition of laden resistor RL is to shoot extremely output circuit, have stability to output the characteristic of voltage so.

 

In the working process of circuit of series connection regulated power supply, the requirement adjusts a canal to lie from beginning to end enlarge condition. Be equal to load current through adjusting tubal electric current, because this must choose proper high-power be in charge of,adjust a canal, come loose by formulary installation shrinkage fitting buy. Adjust a canal to prevent short circuit or long-term overload to burn out, still set the circuit such as short circuit protection and overload protection commonly in dc manostat.

 

Stabilized voltage diode, english name Zener Diode, call Qi Na diode again. Use Pn to written guarantee retrorse puncture condition, its electric current can change inside very big range and the phenomenon with basic and constant tension, the has stabilized voltage effect diode that makes. [1] this diode is a kind till the semiconductor device that very tall resistance has before voltage of critical and retrorse puncture. On this critical puncture dot, retrorse resistor reduces a very little numerical value, in area of this low block electric current increases and voltage keeps constant, stabilized voltage diode divides shelf according to puncture voltage, because this kind is characteristic, stabilized voltage canal basically is regarded as manostat or fiducial component uses tension. Stabilized voltage diode can establish ties so that be used on taller voltage,rise, pass series connection to be able to obtain taller stable voltage.

 

 

 

Of the volt-ampere character curve of stabilized voltage diode mixing to character common diode is about the same, retrorse character is in retrorse report depress at retrorse puncture voltage, retrorse resistance is very great, retrorse leakage current is dinky. But, draw near when retrorse voltage when the critical value of retrorse voltage, retrorse electric current increases abruptly, call puncture, on dot of this one critical puncture, retrorse resistor falls abruptly to very little value. Although electric current changes inside very big range, and the voltage of two end basically stabilizes diode however around puncture voltage, realized the stabilized voltage function of diode thereby. [1]

 

 

The stable tension that the two end when showing stabilized voltage canal carries rated electricity produce is worth. What this value follows working electric current and temperature is different and change somewhat. As a result of the difference of workmanship, the stabilized voltage value that same type stabilized voltage provides agrees not completely also. For example, the Vzmin that 2CW51 stabilized voltage is in charge of is 3.0V, vzmax is 3.6V.

 

 

The electricity that when showing stabilized voltage is in charge of generation to stabilize voltage, provides through this is worth. When be worth under this, although stabilized voltage canal is not cannot stabilized voltage, but stabilized voltage effect can become poor when; is worth high hereat, want not to exceed rated power loss only, also allow, and stabilized voltage function will be better, but should waste electric energy more.

 

 

Show stabilized voltage provides change of two upright voltage and the specific value that electric current changes. What this ratio follows working electric current is different and change, it is working electric current heals commonly big, dynamic resistor heals small. For example, when the working electricity that 2CW7C stabilized voltage provides is 5mA, when Rz is 1OmA for 18Ω; job electric current, when Rz is 20mA for 8Ω; , rz is 2Ω; ” 20mA maintains this numerical value basically.

 

 

Allow temperature rise decision by chip, its numerical value is stable voltage Vz and the product that allow Izm of the biggest electric current. For example the Vz that 2CW51 stabilized voltage is in charge of is 3V, izm is 20mA, the Pz that should be in charge of is 60mWo

 

 

If the temperature of stabilized voltage canal changes, its stable voltage also can produce little change, temperature changes 1 ℃ place causes pipe the opposite change quantity of two upright voltage is temperature coefficient namely (unit: ﹪ / ℃ ) . Say stabilized voltage value to attribute neat accept breakdown under 6V commonly, temperature coefficient is negative; Of prep above 6V belong to avalanche puncture, temperature coefficient is. When temperature is elevatory, depletion layer is reduced, in depletion layer, atomic price electron rises to higher energy, lesser electric field intensity is OK arouse valence electron from inside atom puncture of generation neat accept, because its temperature coefficient is negative. Avalanche puncture happens in depletion layer when intensity of wider electric field is inferior, temperature increases make oscillatory extent increases crystal lattice atom, block up carry stream child motion. Below this kind of circumstance, increase retrorse tension only, ability produces avalanche puncture, accordingly the voltage temperature coefficient of avalanche puncture is. This is why stabilized voltage value is in charge of value of its stabilized voltage to follow temperature to increase gradually for the stabilized voltage of 15V, and the account that stabilized voltage value manages value of its stabilized voltage to follow temperature to be reduced gradually for the stabilized voltage of 5V. For example the temperature coefficient that 2CW58 stabilized voltage is in charge of is + 0.07%/°C, namely temperature every are elevatory 1°C, value of its stabilized voltage will be elevatory 0.07% .

 

To power source the requirement compares tall situation, can be in charge of series connection to rise with the stabilized voltage with two contrary temperature coefficient as compensation. Because be compensated each other, temperature coefficient is reduced greatly, can make temperature coefficient achieves 0.0005%/ ℃ .

 

 

Point to the leakage current that stabilized voltage diode generates below the retrorse voltage in the regulation. For example when the VR=1V that 2CW58 stabilized voltage is in charge of, IR=O.1uA; is when VR=6V, IR=10uA.

 

 

Main show is in the breakdown of stabilized voltage diode open circuit, short circuit and stabilized voltage value are not stable. In these 3 kinds of breakdown, before one kind of breakdown shows power source voltage to lift; Expression of 2 kinds of breakdown is power source voltage after become low to be not stabilized to 0 bend over or output.

 

 

Look from the appearance, the metal encloses the positive electrode one aspect of the matter of body of stabilized voltage diode to be flat look, negative pole one aspect of the matter is semicircle face form. Model seals stabilized voltage diode imprint on body the one aspect of the matter that has chromatic number is negative pole, another end is positive electrode. Not clear to the mark stabilized voltage diode, also can use avometer differentiate its polarity, metrical method and common diode are identical, use avometer R×1k file namely, two lists the pen receives two electrode of stabilized voltage diode respectively, measure after giving a result, again two watches pen has exchange measure. In measuring an outcome twice, block value is lesser that time, what black list pen receives is the anode of stabilized voltage diode, what red watch pen receives is the negative pole of stabilized voltage diode. What point to here is avometer of type of pressing with a finger.

 

 

Product of country of diode of lubricious annulus stabilized voltage is very scarce, great majority comes from abroad, be in the majority with Japanese product especially. Diode of stabilized voltage of general quality annulus mark has model and parameter, detailed data can be checked on component manual. And bulk of diode of lubricious annulus stabilized voltage value of small, stabilized voltage is in small, power mostly 10V less than, extremely easy puncture damages. The exterior of diode of lubricious annulus stabilized voltage and lubricious annulus resistor are very similar, make a mistake very easily consequently. The lubricious annulus on diode of lubricious annulus stabilized voltage represents two meanings: It is delegate number, 2 it is to represent decimally digit (normally diode of lubricious annulus stabilized voltage is to take a fraction, with palm colour specification. Also can understand for fold namely: ×10 (- 1 square) , the number of specific color correspondence is the same as lubricious annulus resistor)

 

Because volume of diode of small-power stabilized voltage is minor, it is more difficult that model is tagged on pipe, the nominal and stable tension that so product of a few abroad uses lubricious annulus to express it is worth. As lubricious annulus resistor same, the color of annulus has palm, red, orange, yellow, green, blue, violet, grey, white, black, they are used respectively represent numerical value 1, 2, 3, 4, 5, 6, 7, 8, 9, 0.

 

On some stabilized voltage diode only 2 lubricious annulus, and some has 3 however. Most stand by negative pole for the 1st annulus, from the back ordinal mix for the 2nd annulus the 3rd annulus.

 

Only of 2 lubricious annulus. Nominal and stable voltage is two digit, namely “××V” (a few bend over) . The 1st annulus shows tension 10 numerical value that go up, the 2nd annulus expresses a numerical value that go up. Be like: The 1st, 2 annulus color is ordinal for red, yellow, it is 24V.

 

Have 3 lubricious link, and the 2nd, color of two 3 lubricious annulus is same. Nominal and stable voltage is an integer and contain a fraction, namely “× . ×V” (a few a few bend over) . The 1st annulus shows tension a numerical value that go up. The 2nd, two 3 lubricious annulus (color is same) express jointly very (decimally hind the first) numeric. Be like: The 1st, 2, 3 annulus color is ordinal for grey, red, red, it is 8.2V.

 

Have 3 lubricious link, and the 2nd, color of two 3 lubricious annulus is different. Nominal and stable voltage is two integer and contain a fraction, namely “×× . ×V” (a few bend over) . The 1st annulus shows tension 10 numerical value that go up. The 2nd annulus expresses a numerical value that go up. The 3rd annulus expresses very (decimally hind the first) numeric. This kind of circumstance is scarcer nevertheless, be like: Palm, black, yellow (10.4V) with palm, black, ash (10.8V) the model of diode of commonly used stabilized voltage contrasts watch (note: The diode model from the back is with 1 begin, be like 1N4728, 1N4729)

 

 

Use avometer R×1K to block above all, press a canal that be measured, negative electrode judgement comes out. Dial avometer next block to R×10K on, black list pen receives the negative pole of the canal that be measured, red watch pen receives the anode of the canal that be measured, the retrorse resistance that if measure gotten retrorse resistance to be blocked than using R×1K right now,measures is a lot of less, the specification is measured to be in charge of be in charge of for stabilized voltage; Conversely, if measure gotten retrorse resistance still very big, explain this canal is rectification diode or demodulation diode. This kind of truth that identifies a method is, avometer R×1K blocks the batteries tension that interior uses to be 1.5V, general won’t will be measured to provide retrorse breakdown, make measures resistance greater. And R×10K is blocked when measuring, the voltage of avometer interior batteries is in commonly 9V above, it is stabilized voltage canal when the canal that be measured, when cutting stabilized voltage value to be worth under batteries voltage, namely by retrorse puncture, make measures resistance is reduced greatly. But if be measured to be in charge of,be general commutate or demodulation diode when, no matter use R×1K to block,block with R×10K measure, earning block value will not differ very great disparity. Attention, when the voltage that when the stabilized voltage of diode of the stabilized voltage that be measured R×10K of avometer of value prep above blocks is worth, using this kind of method cannot undertake distinguishing differentiating.

 

How to use 3 end manostat replaces stabilized voltage diode

3 end diode of stabilized voltage of manostat function excel, 3 end manostat is compositive chip, interior has link of enlarge, compensation, feedback, stabilized voltage performance is excellent. Stabilized voltage diode can form shunt-wound manostat below the situation that needs manostat of small electric current, but stabilized voltage effect is not very good, just can use, output electric current is largish exceed stabilized voltage chip with respect to the price of resistor of that current limliting.

 

Same point is the effect that has stable voltage, but different point is much.

 

One · is former it is paralell connection is on circuit; Latter is series connection is on circuit.

 

2 · former power is lesser, control in 1W commonly; Latter power is greater, be in commonly a few W.

 

3 · are former and main the working tension that hints with stable in circuit some; Latter basically is used in for whole or partial circuit provides stability or adjustable power supply source.

 

The stabilized voltage value with 4 former · is fixed; Latter stabilized voltage value is adjustable.

 

Former much application is controlling 5 · circuit; Latter is to apply in power supply circuit.

 

Just act well below puncture circumstance when 6 · former job; The word of latter puncture can be bothered.

 

About 3 end the relevant introduction of manostat and stabilized voltage diode arrives this, if have insufficient place,welcome make a comment or criticism.