barcode reader in asp.net codeproject 5V + in Software

Printer Quick Response Code in Software 5V +

5V +
Decode Denso QR Bar Code In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
Generate QR Code 2d Barcode In None
Using Barcode generation for Software Control to generate, create QR Code image in Software applications.
1 k vout
QR Code ISO/IEC18004 Scanner In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
QR Code JIS X 0510 Maker In Visual C#
Using Barcode creation for VS .NET Control to generate, create QR image in .NET applications.
Figure 1545 Opencollector comparator output with representative external supply connection
Denso QR Bar Code Creation In .NET Framework
Using Barcode printer for ASP.NET Control to generate, create QR Code image in ASP.NET applications.
Draw Quick Response Code In Visual Studio .NET
Using Barcode generation for Visual Studio .NET Control to generate, create Denso QR Bar Code image in VS .NET applications.
15
Encode QR In Visual Basic .NET
Using Barcode generation for Visual Studio .NET Control to generate, create QR Code image in .NET framework applications.
Code-128 Encoder In None
Using Barcode encoder for Software Control to generate, create Code 128 Code Set A image in Software applications.
Electronic Instrumentation and Measurements
Painting EAN-13 Supplement 5 In None
Using Barcode drawer for Software Control to generate, create EAN-13 Supplement 5 image in Software applications.
Paint Code 3 Of 9 In None
Using Barcode creator for Software Control to generate, create Code 3/9 image in Software applications.
5V + Vref vout vin
Bar Code Drawer In None
Using Barcode printer for Software Control to generate, create barcode image in Software applications.
Barcode Drawer In None
Using Barcode generator for Software Control to generate, create barcode image in Software applications.
1 k
Paint Identcode In None
Using Barcode generation for Software Control to generate, create Identcode image in Software applications.
Barcode Generation In Objective-C
Using Barcode creator for iPhone Control to generate, create barcode image in iPhone applications.
vin Vref
Draw Bar Code In .NET
Using Barcode creation for Reporting Service Control to generate, create bar code image in Reporting Service applications.
Bar Code Scanner In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
Two improvements of this circuit will be discussed in this section: how to improve the switching speed of the comparator, and how to design a circuit that can operate correctly even in the presence of noisy signals If the input to the comparator is changing slowly, the comparator will not switch instantaneously, since its open-loop gain is not in nite and, more important, its slew rate further limits the switching speed In fact, commercially available comparators have slew rates that are typically much lower than those of conventional op-amps In this case, the comparator output would not switch very quickly at all Further, in the presence of noisy inputs, a conventional comparator is inadequate, because the input signal could cross the reference voltage level repeatedly and cause multiple triggering Figure 1547 depicts the latter occurrence
Code 128C Recognizer In VS .NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in Visual Studio .NET applications.
GTIN - 13 Generator In VS .NET
Using Barcode encoder for ASP.NET Control to generate, create EAN-13 image in ASP.NET applications.
t vout 5V Volts
Decode EAN-13 In Visual Basic .NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
Scanning EAN / UCC - 14 In VB.NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET applications.
0 0 01 02 03 05 06 Time, s Noisy input waveform 04 07 08 09 1
2 t
Volts
Figure 1546 Waveforms for inverting comparator with offset
20 0 0 01 02 03 05 06 07 Time, s Comparator output waveform 04 08 09 1
Figure 1547 Comparator response to noisy inputs
vout
R2 V R1 + R2 sat v
vin R2 V R1 + R2 sat
vin v+ R2
+ R1 vout
One very effective way of improving the performance of the comparator is by introducing positive feedback As will be explained shortly, positive feedback can increase the switching speed of the comparator and provide noise immunity at the same time Figure 1548 depicts a comparator circuit in which the output has been tied back to the noninverting input (thus the terminology positive feedback) by means of a resistive voltage divider The effect of this positive feedback connection is to provide a reference voltage at the noninverting input equal to a fraction of the comparator output voltage; since the comparator output is equal to either the positive or the negative saturation voltage, Vsat , the reference voltage at the noninverting input can be either positive or negative Consider, rst, the case when the comparator output is vout = +Vsat It follows that v+ = R2 Vsat R2 + R 1 R2 Vsat vin R2 + R 1 (1530)
and therefore the differential input voltage is = v+ v = (1531)
Figure 1548 Transfer characteristic of the Schmitt trigger
For the comparator to switch from the positive to the negative saturation state, the differential voltage, , must then become negative; that is, the condition for the
Part II
Electronics
comparator to switch state becomes vin > R2 Vsat R2 + R 1 (1532)
Since [R2 /(R2 + R1 )]Vsat is a positive voltage, the comparator will not switch when the input voltage crosses the zero level, but it will switch when the input voltage exceeds some positive voltage, which can be determined by appropriate choice of R1 and R2 Consider, now, the case when the comparator output is vout = Vsat Then v+ = and therefore = v+ v = R2 Vsat vin R2 + R 1 (1534) R2 Vsat R2 + R 1 (1533)
For the comparator to switch from the negative to the positive saturation state, the differential voltage, , must then become positive; the condition for the comparator to switch state is now vin < R2 Vsat R2 + R 1 (1535)
Thus, the comparator will not switch when the input voltage crosses the zero level (from the negative direction), but it will switch when the input voltage becomes more negative than a threshold voltage, determined by R1 and R2 Figure 1548 depicts the effect of the different thresholds on the voltage transfer characteristic, showing the switching action by means of arrows The circuit just described nds frequent application and is called a Schmitt trigger If it is desired to switch about a voltage other than zero, a reference voltage can also be connected to the noninverting terminal, as shown in Figure 1549 Now the expression for the noninverting terminal voltage is v+ = R1 R2 vout + Vref R2 + R 1 R2 + R 1 R1 R2 Vsat + Vref R2 + R 1 R2 + R 1 R1 R2 Vsat + Vref R2 + R 1 R2 + R 1 (1536)
Copyright © OnBarcode.com . All rights reserved.