Informe de electronica

Practice 2 – Measurement of the Parameters Hybrid H

Luis Alexander Piñeros Garzon, Miller Fernando Barrera Alvarado

Corporación Universitaria del Meta

Villavicencio, Colombia

lucho852@hotmail.es

millerba_ultra@hotmail.com

 RESUMEN: En la siguiente practica de laboratorio vamos a implementar un circuto con transistor y potenciómetros que harán la función de fuentes de voltaje variables, las cuales  nos permiten determinar los parámetros hibridos H de este mismo bajo ciertas restricciones.

PALABRAS CLAVE:

• Corriente
• Parámetros hibridos H
• Impedancia
• Admitancia
• Transistor BJT
• Voltaje

ABSTRACT: In the next practice of lab we will to implement a circuit with transistor and potentiometers that will function of voltage source varying, which allow us to determine the parameters hybrid H the same under certain restrictions.

KEYWORDS:

• Current
• Parameters Hybrid H
• Impedance
• Admittance
• BJT Transistor
• Voltage

1. INTRODUCTION

For the embodiment of a transistor design, it is necessary to determine the parameters of the transistors hybrids to be used for a specific operating point.

This determination can be done in several ways: practiced by manufacturer's manual, with transistor curve tracer or using simulation.

In this laboratory is to determine the parameters using a real circuit using simple relations, the parameters are determined. Note that if you change or alter the transistor operating point, necessarily must re-determine the parameters.

1. DEVELOPMENT OF CONTENTS

Acquire any low power transistor. We recommend using one of the following transistors: 2N2222 or 2N3904.

At this point we decided to use the 2N2222 transistor due to its characteristics it has, its basic operation and low economic cost.

 Note the characteristics given by the manufacturer of the transistor used.

[pic 1]

[pic 2]

Select ICQ and VCEQ. These values ​​continue working.

Table of values ICQ y VCEQ

1. Build a circuit that can determine the parameters, taking into account the values ​​chosen in the previous paragraph. We suggest the following circuit.

[pic 3]

Optional Circuit

[pic 4]

With this circuit can determine the four parameters H hybrids, varying simultaneously in two voltage sources as follows:

varying VBB y or VCC simultaneously assure obtaining ICQ y VVEQ. With both established values​​, measured IBQ y VBEQ. The four measurements are performed with instruments for this purpose is placed in the circuit.

Table of values ​​of the transistor in terms of Q

This section has complete operating point including β=ICQ/IBQ.

Table of values β

Next step determine the parameters H(hie, hre, hfe, hoe). The parameters are defined as:

   |   VCE   constante.[pic 5]

   |   IB   constante.[pic 6]

          |   VCE   constante.[pic 7]

   |   IB   constante.[pic 8]

constant maintenance VCE=VCEQ, vary the two sources to obtain a IB2>IBQ. Correspondence measure VBE2 y la corriente IC2.

Tabla de valores para IB2>IBQ siendo VCE=VCEQ

Now, constant maintenance VCE vary the two sources to obtain a IB1BQ. Correspondence measure VBE1 and current IC1.

and current IB1

With these measures and can be calculated hie y hfe.

   |   VCE   constante.[pic 9]

          |   VCE   constante.[pic 10]

Table of values ​​for hie and hfe

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