AC/DC

Note: This docuent guides you to create a power supply for the HP48, I don't give any warranty, and it's all your responsability if you mesds up you calculator, I only show to you the information.
Other thing: My english is not good :)

Hi there. I have not visited HPCalc since a year, and I remember that I have a file in there, a file wich tell's you the way to connect the HP48 with a powr supply, it was a little difficult to do it but my HP48G still working.

Introduction

Nota: I'll think you know a little bit of electronics systems, if you have more knowledge in electronics maybe you'll find this document a little bit bored.

In this document I'll show you the way to construct a power source for the HP48 and it's very easy. You will spent aprox. 12US$.

What a power source does? Basically this power source reduces from 120VAC to 4.5VDC

AC
This type of current it's changing all the time, it means the voltage and current are chaning constantly in an especific frecuency

DC
This type of current are constant all the time, it has not frecuency.

How does the power source works?

It has 3 basic steps:


No reduction

Reducted signal

Sin rectificar

Señal rectificada

Señal no filtrada

Señal filtrada

Element that we will use

Otros:

 

*Nota: Hay dos tipos de transformadores, los que no tienen divisor y los que si tienen divisor, la forma para poder diferenciarlos es muy fácil, el que no tiene divisor no tiene 3 patas en uno de sus lados, en cambio en el que tiene divisor sí tiene 3 patas en uno de sus lados. Debido a que del transformador depende los diodos, entonces, si utilizamos un transformador con divisor sólamente necesitaremos 3 dodos IN4001, en cambio si utilizamos el transormador sin divisor utilizaremos el puente de diodos y un diodo 1N4001.

Procedimiento

Como ya habíamos mencionado anteriormente, hay dos formas diferentes de circuitos dependiendo del transformador que hayas conseguido.