Circuits diode valves

1) Determination of the point of job of a diode valve:

It is necessary to find the intersection between the static curve of the diode valve and the straight one of cargo that corresponds to the equation it intersects asse the v_D = 0 per and asse the _{the D} = 0 for v_D = v_in.

 

2) Construction of the dynamics characteristic of a diode valve:

Currency for one given v_in the value of_{the D} in the job point (…obtains first point (v in such a way_in , i_To) of the dynamics characteristic) dopodichè changes v_in and therefore the straight one of cargo trasla in parallel with if same characterizing a new point of job (v_in , i_To) and therefore also a new point pertaining to the dynamics characteristic, joining it to previous it completely it is determined be a matter itself of one straight to constant slope, moreover being v_out = i_DR_L it has the same shape of the transcaratteristica (…curve that establishes the tie between the tension of escape and the tension of income of the circuit).

3) graphical Construction of marks them of escape from a diode valve:

Trace the transcaratteristica dopodichè ribalta the shape of wave of marks them of income and for every time trace the value of marks them of escape that law from the transcaratteristica.

 

4) Linearizzazione at times:

Method of the states

It is assumed that every present diode valve in the circuit is in state ON (…in the which case is replaced with a generator V_g in series to a resistance R_F @ 10W ) or in state OFF (…in the which case is replaced with a resistance R_r @500kW ), obtains an analyzable linear circuit second the laws of Kirchhoff ¬, once resolved must be verified that it turns out obtained to you agree with the made assumptions.

Method of the releases

Imposing_{the D} @ 0 and v_D= v_g points are found suddenly i that they go brought back in the plan of the transcaratteristica, they must then be joined from broken whose slope on the left of 1° the point is obtained imposing v< < the 0 while the slope to right of the last point is obtained imposing v > > the 0.

 

5) Determination of the point of job in the case of two diode valves:

Ribalta and trasla the straight characteristic of according to diode valve so that it passes for v = v_in , the intersection with the characteristic of the first diode valve in particular characterizes the point of job of both if the two diode valves are equal, the point of job posiziona stablily to v_in and this is one of the reasons for which in the integrated circuits it prefers to use an active cargo rather than one resistance.

 

6) Clipper (Tosatore):

Draft of a circuit in degree to make oneself to pass in escape only a part del marks them of income, is constituted from a battery of reference always mail in parallel, from a diode valve that pu² to be placed or in series or parallel and from a resistance whose position is mutual respect al diode valve. In the choice of the position of the diode valve account must be held that in its equivalent circuit has an ability in parallel that therefore leaves to pass marks having them vhf moreover if the diode valve is placed in series to the generator this must have one low inner resistance in how much the direct resistance of the diode valve is much lowland and therefore it is not in a position to separating opportunely.

The analysis of the circuit pu² to develop itself with the method of the releases, in particular characterizes the point suddenly of the diode valve and the slopes of the straight ones that pass for it, must be always had clearly in mind that stà tracing itself the transcaratteristica and the slope is the relationship between income tension and escape tension and therefore is unitary if the two tensions coincide.

 

7) Slicer (Slicing machine):

It is constituted from 2 ideal diode valves places in parallel to the tension of income (…from which they are separates through one R resistance to you) with the tips in opposite backs and everyone with in series one battery of various value. It is had that the excursion of the income tension comes limited to the values of the two batteries, in such a way comes true therefore one squadratore whose performances improve headlong placing two diode valves in contropunta.

 

8) Sampler (Clipper):

It is a circuit with which it makes so that there is in escape only marks them of income when tension of digital control is the qualification from part of one them. E' essentially constituted from a bridge of diode valves with the pilotage to two ends of the bridge, the tension of income to 3° extreme and the tension of escape captured through one resistance to the 4° extreme of the bridge. The analysis is carried out with the superimposition of the effects, before supposes the presence of the single pilotage and then the presence of the solo marks them of income, it obtains that in a branch of the bridge the current slides in opposite backs in the two cases, well the condition must be placed that the current that slides in the back of the conduction is greater of the current that slides in the back of the interdiction.

 

9) Rectifier to one semiwave:

It marks them of income comes applied to a diode valve in series to the cargo resistance, if the anode is towards the generator it concurs the passage of the sun positive semiwaves, the current that slide in the circuit are , neglecting v_g the medium value of the current and therefore can be calculated elaborating which obtains that extension as the rectifier to a semiwave can be replaced from a having generator tension to empty and one inner resistance R_f .

An ability in parallel to the cargo resistance can be inserted realizing therefore a capacitivo filter, in particular is had that when the diode valve leads the ability it loads while when it is interdetto, the ability discharge on the resistance R_L. The course of the current in the diode valve is given from the sum of the current that slides in the condenser and of the current that slides in the cargo, it is observed that its value maximum increases growing of C therefore it does not have too much to be elevated in order to avoid to subject the diode valve to excessive currents, must some be too much small otherwise does not reduce the ripple. In the interval in which the diode valve it does not lead the escape tension decreases esponenzialmente from the value begins them, has .

 

10) Rectifier to 2 semiwaves:

The problem of the rectifier to a semiwave is that the valor medium that is obtained is not much high, and pu² not to misuse itself the condenser that acts as from they fly in how much are created of the currents that they can break off the diode valve, then it comes true a balanced transformer for which the positive semiwave it slides on the advanced side and the negative semiwave, invert, slides on the inferior side, the result is that on the cargo place on the taken one they centers slides both the semiwaves, finds and therefore .

An approximate analysis of the circuit can be made supposing C much great therefore from which drift and therefore the moment of I prime is in correspondence of which is had. Intuitivamente being V_R the tension of ripple, has where V_R is obtained from the law of discharge of the condenser where T₂ is the interval in which the condenser discharge, it must be , in the best one of the cases therefore .

 

11) Regulation:

It says the how much varied tension to us to empty of the local p0wer source regarding the tension that is had if a cargo is connected.

the expression is in these terms because we want that it is a positive number and to such aim enough to observe that the tension to empty is sure greater of the tension that is had in presence of a cargo.

 

12) Detector of peak:

Modulating can be extracted from marks modulated them in AM by means of a diode valve in series to the parallel of a resistance and of a condenser to the heads of which the escape is captured, it is had that when the diode valve leads, the condenser is loaded in order then to unload itself when sopraggiunge the negative semiwave of marks modulated them. The optimal constant of time of group RC is obtained imposing that the slope of the envelope is smaller of the slope of the exponential , is obtained:

 

13) Clamper (Fissatore):

We suppose of having a shape of medium wave to valor null, can maintain the same shape of wave but fixing of the medium value to a datum level, in particular the Clamper with tension of reference to 0V is come true with a condenser in series to a diode valve and the escape taken to the heads of the diode valve, during the positive semiwave the diode valve leads and the condenser is loaded to the maximum value V_m , when the interdice diode valve in escape is had .

The problem is that the condenser cannot be unloaded and therefore does not follow marks them of coupled income remaining to the maximum value, comes therefore inserted a resistance in parallel to the diode valve and like last modification one battery V_R in series to the diode valve that concurs to couple the income to the wished tension of reference.