Hobby Projects - Insulation tester, LED Circuits, Meters.

Wednesday, April 24, 2013

Experiments with the LM2575

The standard buck regulator circuit delivers a +5V output. This is a rather straightforward circuit and will operate with a wide spread of component values. Optimal values should be selected however to get minimal ripple, minimal noise to the power source, maximum efficiency etc. Note that the quiesent current is about 10 to 14mA.

Experiments with the LM2575

Here is a nice way of using this regulator, this can be used for CMOS opamps as you have a -5V too. That means a portable instrument may find this design useful.

The TI Datasheet Layout Guidelines

LM2575 Switching Regulator
LM2575 - Step-Down Adjustable Voltage Switching Regulator with Output Enable

 The Spirit of Hacking and Fixing, Giving back Life to Old Instruments.

Fluke 8050A LCD display replaced with LED seven-segment

"Recently I was able to cheaply buy a second hand Fluke 8050A made in the early eighties. It is a nice 4.5 desktop digit meter, but a typical problem seems to be that the LCD wears out and goes black. Replacement LCD displays are hard to find, not cheap and probably lead to similar problems in due time."

Friday, April 12, 2013

Tone generation using 89C2051 - AirBorn

This is a nice educational reference project based on 89C2051, an 8051 derivative. This uses the Uses analog switches to steer test tones and results. Programmed in assembler to produce pure 1khz tone. 

Tone generation using 89C2051 -  AirBorn

Tone generation using 89C2051 -  AirBorn

Using a multimeter

"The example meter that we are demonstrating is typical of many economical digital multimeters that you can purchase, hopefully these instructions will be of some use to you no matter what brand or type of meter you use. "

My Notes

Students and Hobbyists can study all the example projects and tutors in this site to become more skillful. They have pages that show how a PCB is made and things like Circuit Design and Prototyping. This Site also happens to be one of the oldest resources in the web for Electronic Embedded Designs.

Practical Electronics

Practical Electronics
Basic Electronics, EE Reference Resource, Analog, Digital, Power and Electrical.

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