Voltage Detection Circuit Response Respective To Undervoltage Biology Essay

Both simulation and existent hardware design was put to several trials for every phase of the detector. Prior to the existent testing, the detector was tested by bring forthing fake signals in the package. When mistakes occurred, the mistake were identified instantly and debugged.

Once the peculiar characteristic was ready and confirmed, it was tested in hardware proving. It so compared with the simulation proving consequences. The consequences and findings of the measuring trials are discussed in this chapter.

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Several simulations and trials were conducted to guarantee it is runing satisfactorily. Any mistakes are identified and being troubleshoots. The list of simulations and proving is shown in Table 4.1 Further inside informations about the consequences and findings are explained in this subdivision.

Table 4.1: List of simulation and proving conducted.No.

Simulation and TestingBrief Description1Step down transformerTo look into the electromotive force of input and end product step down transformer.2RectifyingTo look into whether AC electromotive force is rectified into DC electromotive force.3Voltage RegulatingTo mensurate changeless end product electromotive force of electromotive force regulation circuit which are Vcc and Vdc.4FilteringTo look into the filtering DC electromotive force.5SmoothingTo smooth the rippling DC electromotive force into changeless DC electromotive force.6Time Response Analysis.To mensurate how fast AC to DC electromotive force is stabilised.

7DC Sweep AnalysisTo supervise end product value of each comparators by changing input electromotive force, Vin.8Comparison of Undervoltage, Normal and Overvoltage ConditionTo find the electromotive force sensing circuit response respective to undervoltage, normal and overvoltage status.9Comparison of simulation consequences and existent hardware consequencesTo find the measurement mistake of the existent apparatus and trouble- shot.


1.1 Step down transformer

Oscilloscope 1 ( XSC1 ) is connected to the circuit as Figure 4.1. Impart A investigation is connected to the primary side, while Channel B investigation is connected to the secondary side of the transformer T1. The transformer T1 has ratio of primary to secondary peers to 10, which is 230VAC to 24VAC. Therefore, the intent of this simulation is to place the ratio of measure down transformer satisfied the transformer ratio apparatus.Figure 4.

1: Measurement apparatus of measure down transformer.For initial apparatus, input supply electromotive force is set to 230Vrms which is in normal status. Input and end product wave forms of measure down transformer T1 are shown in Figure 4.

2. Both wave forms are in the same stage of 50Hz and primary to secondary transformer ratio is about to 10:1. Cursor 1 is pointed at peak electromotive force of the primary and secondary transformer in clip 1, T1 while pointer 2 is pointed at peak electromotive force in clip 2, T2. As the peak electromotive force is measured in the graph, Vrms can be calculated by spliting the peak electromotive force with a?s2.

End productInput signalFigure 4.2: Input & A ; end product wave form of measure down transformer

4.1.2 Rectifying

As shown in Figure 4.3, CRO XSC1 is so connected to + terminus of span rectifier D4, while land is connected to – terminus of span rectifier D4.

Purpose of this simulation, is to place the feature of electromotive force after rectifying AC to DC electromotive force. As shown in Figure 4.4, the end product electromotive force of the rectifier is in full moving ridge DC electromotive force, as span rectifier is a full- moving ridge rectifier. Bridge rectifier excessively can be replaced by four individual power rectifying tubes. However, the electromotive forces are non in pure DC electromotive forces, in definition varies between lower limit to maximal electromotive forces.

Maximum peak electromotive force is 23.3 V and minimal electromotive force is 15.1 V.Figure 4.

3: Measurement apparatus of rectifier for electromotive force regulator.Figure 4.4: Output wave form of rectifier D4.

4.1.3 Voltage Regulating Circuit.

Measurement apparatus for zener rectifying tube and electromotive force regulation circuit are shown in Figure 4.5. Oscilloscope XSC1 is used to supervise waveform feature of the end product electromotive force of electromotive force regulator LM7805 ( Vdc ) and zener rectifying tubes ( Vcc ) , while multimeters ( XMM1 and XMM2 ) are used to mensurate end product electromotive force magnitudes. As discussed in old chapter, zener rectifying tube used to modulate rectifying electromotive force into changeless electromotive forces of Vcc. Vcc is the supply electromotive force to LEDs and electromotive force comparators LM339. On the other manus, end product regulator LM7805 ( Vdc ) is used for to put mention for over electromotive force and under electromotive force in electromotive force sensing circuit.

It is of import to guarantee the Vcc is about 15V and Vdc peers to 5V.Figure 4.5: Measurement apparatus of electromotive force regulation circuitVdcVccFigure 4.6a: Wave form of electromotive force regulator end products ( Vcc and Vdc )Figure 4.6b: Magnitude Vcc ( XMM1 ) and Vdc ( XMM2 )Consequences of the simulation are presented in Figure 4.6a and 4.

6b. From Figure 4.6a, Vcc and Vdc electromotive force is changeless through clip. Furthermore, magnitudes of Vcc and Vdc are 14.97V and 5V severally. Even though Vcc is non equal to 15V accurately, it is acceptable since the electromotive force is sufficient for supply electromotive force comparator and LED.

Specifically, LM339 acceptable supply electromotive force is between 2V to 36V. Similarly to LED used. If 12V LED is being used, 15V of Vcc is sufficient.

4.1.4 Filtering Circuit

To mensurate the filtering end product electromotive force, the measuring apparatus is configured as in Figure 4.7. Impart A investigation is connected to + terminus of span rectifier and the land is connected to the – terminus while channel B investigation is connected to resistor R5 to mensurate the electromotive force after filtrating. Impart A and B wave form is compared to see the difference between those end product electromotive forces. The end product electromotive force wave forms are shown as in Figure 4.

8. From the graph, Va extremum electromotive force is about 24V while Vb is smaller. Vb is smaller about by ratio of 0.1, because of electromotive force spliting resistances. Furthermore, Vb have much less ripple comparison to Va electromotive force wave form.

Figure 4.7: Measurement apparatus for rectifying and filtrating circuit.VbVirginiaFigure 4.

8: Output wave form of rectifying and filtrating circuit.

4.1.5 Smoothing DC circuit

To better the DC electromotive force signal, smoothing DC circuit is connected by adding capacitances parallel to the resistance of the filtering circuit.

It is of import to guarantee that end product electromotive force of the smoothing circuit ( Vin ) is about in right ratio. For illustration, 2.30Vdc is represented the 230VAC. Therefore, the measuring apparatus is performed as in Figure 4.9, and the consequence is in Figure 4.

10. From the consequences, it is observed that the capacitance managed to smooth the DC electromotive force signal into pure DC after 2nd capacitance. Ripples do be at first smoothing circuit, but merely after 2nd smoothing capacitance, the end product electromotive force is in pure DC signal.Figure 4.9: Measurement apparatus of smoothing DC circuitChannel AngstromChannel BacillusFigure 4.10: Output wave form of smoothing DC circuit.

4.16 Time Response Analysis.

Time response of this electromotive force sensing circuit is measured based on how fast the electromotive force is stabilised from AC to DC electromotive force, to be input electromotive force of the electromotive force sensing circuit. In voltage sensing circuit, the clip response is based on the comparator LM339 characteristic itself, which can be found in the datasheet. From the datasheet, LM339 response clip is found to be 1.

3us, which is considered as instantaneous, several to the electromotive force fluctuations.Figure 4.11: Time Response Analysis of DC input electromotive force, Vin.

DC Sweep Analysis

In mention of Figure 4.12, electromotive force sensing circuit receives supply electromotive force from AC to DC circuit as stated antecedently from old chapter. There are two different changeless supply electromotive forces which are Vcc and Vdc. Vcc is the supply electromotive force for comparator and LEDs, while Vdc is used to find the electromotive force mention of over electromotive force and under electromotive force bound. Vin, is the input electromotive force which specified ratio varied between the three chief scopes depending on the status, so, Vin is compared to the Vref of each bound.

DC Sweep Analysis is performed to supervise the end product value of each comparator respective to the input electromotive force fluctuations. In this analysis, input electromotive force, Vin is varied from 0V to 5V.The end product pin of comparators are monitored as illustrated in Figure 13a,13b and 13c.Figure 4.12: Voltage sensing circuit conventional diagramFigure 4.13a represents end product electromotive force of pin 2, comparator U1B, which used to compare overvoltage status. As can be seen in the figure, when Vin more than the overvoltage bound which is 2.50V, the end product electromotive force pin 2 is low, therefore current from the Vcc supply can be flow through unfastened aggregator.

Output electromotive force of pin 2 is high when Vin is less than 2.50V. Even though the high value is somewhat less than 15V, current still non fluxing through the unfastened aggregator. Vice versa, the end product electromotive force at pin 1, comparator U1A is low merely when Vin is less than under electromotive force bound which is 2.15V and end product is high when Vin is more than 2.15V.

The response can be seen in Figure 4.13b. During normal electromotive force status, which is between 2.15V and 2.

50V, the end product pin 13 of comparator U1D is low and when Vin is outside the normal scope the end product is high as shown in Figure 4.13c.Figure 4.13a: DC sweep analysis of end product comparator U1B.Figure 4.13b: DC sweep analysis of end product comparator U1AFigure 4.13c: DC Sweep analysis of end product comparator U1D

Comparison of Undervoltage, Normal and Overvoltage Condition

The following measure to place the response of the electromotive force sensing circuit is by supervising the light breathing rectifying tube ( LED ) responses several to the fluctuation of the electromotive force. In voltage sensing circuit, there are three different colorss which represent each electromotive force conditions.

They are ruddy, xanthous and green ; indicate overvoltage, undervoltage and normal electromotive force status severally. Furthermore, it is noted that the fluctuation electromotive forces are defined in Vin, which are the premises of the supply electromotive force. It is assumed that the ratio of Supply Voltage: Vin is peers to 100: 1.

Table 4.2 describes the consequences of the comparing response during overvoltage, normal electromotive force and undervoltage conditions. These simulation consequences are based on the combination of AC to DC circuit and electromotive force sensing as shown in Figure 4.14.Table 4.2: Voltage sensing circuit responses ( simulation )ConditionSupply Voltage( Vac )Vin( V )Coloring material of LED ON.

Red( Overvoltage )Yellow( Undervoltage )Green( Normal )Overvoltage2802.79
































From the tabular array, ruddy LED is lit up during overvoltage status is detected.

Overvoltage is detected whenever Vin is more than 2.50V. Yellow LED lit up during undervoltage status which is when Vin is less than 2.15V.

When neither overvoltage nor undervoltage status occurred, merely green LED lit up bespeaking the supply electromotive force in between the acceptable electromotive force scope ; 2.15V to 2.50V. However, there is somewhat difference between supply electromotive force and Vin, which is non satisfied the ratio 100:1.

Mistakes and inaccuracy will be discussed in following subtopic.Figure 4.14 Combination of AC to DC circuit and electromotive force sensing circuit.Comparison of simulation consequences and existent hardware consequencesIt is of import to prove each circuit in this undertaking to guarantee it is operate satisfactorily.

Beside proving and measuring in simulation package, hardware proving excessively is performed. In both AC to DC circuit and electromotive force sensing circuit, resistances value play of import function in electromotive force dividing and scene of electromotive force mention. Therefore, before building the circuits, value of each resistances used are measured as tabulated in Table 4.3.Table 4.3 Resistors measuringBreadboardPrinted Circuit Board ( PCB )ResistorsActual Value ( ohm )Measurement Value ( ohm )Measurement Value ( ohm )R15k5k5kR21k1k1.

1kR3180k178k179kR410010099R510k9.4k10kR610k9.6k9.6kR715k15k15kR815k15k15kR918k18k18kR1024k24k24kR111k1.1k1kR121k1k1kR131k1k0.99kR1416k15k14.9kR16100100FuseBreadboardPrinted Circuit Board ( PCB )ResistorsActual Value ( ohm )Measurement Value ( ohm )Measurement Value ( ohm )R1711k9.

7k9.2kR1810k10k10kR1910k10.1k9.8kR20100k99.8k99kAs some of the resistances are non in their exact value, it is expected that there is inaccuracy during hardware proving particularly in voltage sensing circuit. Based on the tabulated Table 4.4, Vin might differ much from the right value.

Therefore, it affects the indicant during each status which farther analyses are discussed in following subtopic.Table 4.4: Voltage sensing circuit responses ( hardware )ConditionSupply Voltage( Vac )Vin( V )Coloring material of LED ON.Red( Overvoltage )Yellow( Undervoltage )Green( Normal )Overvoltage2802.76



































4.2 Problems Occurred and Trouble Shooting

First job occurred is the affiliated wires are loose and disconnected internally, particularly the crocodile cartridge holder wires. It caused the circuit non operated and at first it is hard to follow the job since the circuit is in right constellation. After checked the wire by utilizing the diode trial of the multimeter, the jobs are solved.Second job existed because of the effects due to really high current that non checked carefully before executing experiments. Some of the resistances can non stand high current particularly resistance placed on the AC circuit.

As a consequence, the resistance damaged but non able to trip the circuit efficaciously. The job is solved by replacing the resistance value with fuse, which is safer and the circuits can be protected more expeditiously. Furthermore, to get the better of the jobs occurred once more, each constituent is double-checked before put ining in circuit building.Next, most of the clip, the operation of circuit is interrupted due to breadboard internally connexion is damaged. Internal connexion of the bread board can non be detected on the topographic point at the wire is connected indoors and it involves with many holes of connexion. However, it can be checked utilizing diode trial of the multimeter to the holes that need to be connected. In add-on, for farther turning away of this mistake, the circuit is so implemented into printed circuit board, which the connected wire is so replaced by affiliated music director, which is Cu.Besides that, inaccuracy of circuit operations existed in this undertaking.

Therefore, a few values of resistances are changed in order to increase truth. Plus, type of light breathing rectifying tubes is changed and doorbell is added for an sweetening.


3 Analysis of Experimental & A ; Simulation Result

Having conducted several trials and simulations, it can be concluded that this undertaking which is overvoltage detector for industrial contraption protection could execute the electromotive force sensing during overvoltage, undervoltage and normal electromotive force conditions.However, the chief downside issue is accuracy. The AC to DC circuit developed has the inability to observe transient due to the measure down transformer and the electromotive force modulating circuit. Therefore, even though comparator LM339 has the ability to observe electromotive forces up to 1.3us clip response, due to inadequate power- supply filtering and hapless foundation, this electromotive force sensing circuit sacrifices the stableness.

Besides, from the consequences, largely jobs and mistakes occurred during hardware proving compared to simulation proving. The chief ground is there are mistakes in measuring of electronic constituents used particularly resistance. First job occurred is the Vrms of full- moving ridge DC electromotive force is smaller than expected in simulation consequence.

Furthermore the ratio Vsupply: Vin differ from the premise of ratio 100:1. Since the ratio is non precisely accurate, the response of the electromotive force sensing may be affected. For illustration, by mentioning to Table 4.

4, when Vsupply is 252Vac, Vin is 2.50V. There are few consequences of proving where there is more than one LED are lit up at the same clip. It occurs particularly when the input electromotive force is between two conditions.

The ground is because of hysteris occur in the typical comparator. Hysteris go on if the end product electromotive force unable to alter outright several to the fluctuation of electromotive force. It can be overcome by linking resistance analogue to end product pin and + terminus of the comparator.Error excessively was introduced through improper usage of multimeter or power supply. On the contrary, the measuring mistakes when utilizing step down transformers were really high, where the measured values were higher than existent values. The chief ground might be due to amplified measuring mistake due to high electromotive force addition.Since this undertaking concerned to be used in Malaysia, temperature storage may non be a major issue as day-to-day temperature is non varied drastically.

However, it is noted that the of import constituent which is LM339, has storage temperature scope, which is -65°C to 150°C and its operating temperature scope is 0°C to 70°C.2.4 Operating Temperature Range.


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