Sunday, February 07, 2016

Millivolt Circuit ICL7129 MAX7129

My application is to calibrate some instruments with help of this source. I've studied your circuit earlier also., but I want a battery operated mV source. upto 100mV full scale which is portable but still very accurate. The better the accuracy more good for me! I want to use 9v battery or a set of rechargeable batteries for powering this circuit.

I've constructed some prototype tell me how can I send you the schematic? (file format e.g. jpg, *.tiff, *.bmp etc..., i'm using Orcad 9.2 and Express PCB Schematic softwares for Schematics).

Also I need a 4 1/2 digit LCD display for this circuit(Or any good one). I'm referring ICL7129/ Max7129 IC datasheet for this. Do you have any 2v DVM/ DPM circuits, can you please email me the same! ...please!

Mail from MO

Beckman Multimeter with the  ICL7129

"Unlike the HD110 however, this is a 20,000-count 4½ digit model with RMS-responding AC capability."

Beckman Multimeter with the  ICL7129

ICL7129A - Low-Noise, 4 1/2 Digit, Single-Chip ADC with Multiplexed LCD Drivers

The Maxim ICL7129A/MAX7129 is a high precision monolithic 4-1/2 digit A/D converter that directly drives a multiplexed liquid crystal display. Using a novel "successive integration" technique, the

About millivolt source look here Circuits FAQ - Millvolt Source see another see millivolt source, pdf at Analog-2 - Instrumentation Circuits

delabs


I have completed the millivolt circuit, but I need some more information regarding using ICL7129 for driving a 4 1/2 digit LCD for displaying the

Mail from MO

Saturday, February 06, 2016

Metal Detector Circuits Problem

With the best wishes for you. I found your address and browsed your website. I have a question and hope to take your help and answer.

I need to good metal detector's circuit and I find several in the web, any of them worked ? what is a problem in them and where can I find one that works with best depth? Could you design or point the mistake in some circuits? Thank you for your answer beforehand.

delabs - See my Related Page at  Metal Detector Projects

Metal Detector Circuits Problem

Mail from AS


delabs

Thank you for your answer and sites. But some of them that are professional namely "twin loop" built but it has problem and didn't work.

I think it may be a indicated, there is a problem with them. How can I make it correctly? could you proper design such circuits?

I am not professional and of you do, I will pay for your works.

Reply from AS

If you clearly specify what you want with a drawing, And indicate what you may be able to pay and your contact details too.......

Then, I will publish your request in my site. People visiting my pages may contact you. You can Try it out, I may not be able to help now.

delabs

(PS - You can offer a solution to AS's Problem, post your design page details, All Comments are moderated, Commercial or Business comments will be deleted, designers can indicate homepage.)

Friday, February 05, 2016

LF353 - Wide Bandwidth Dual JFET

These devices are low cost, high speed, dual JFET input operational amplifiers with an internally trimmed input offset voltage (BI-FET II™ technology). They require low supply current yet maintain a large gain bandwidth product and fast slew rate. In addition, well matched high voltage JFET input devices provide very low input bias and offset currents.

LF353 - Wide Bandwidth Dual JFET 

(Google Talk Transcript - Year 2006 )

Audio Tone Control with LF353 - Bass and Treble and Mid-Range(Presence). Bass is like Drums and Woofer. Treble is like Guitar and Tweeter. Mid-Range is like Vocal and Medium Speakers.

This circuit is to demonstrate the capability of the Opamp. The post is more related to instrumentation.

Audio Tone Control with LF353

TF (12:16:46 PM): i need a clarification on OpAmp
delabs (12:16:57 PM): ok tell me
TF (12:20:55 PM): what parameter should I check to know the frequency response of an Opamp
TF (12:20:55 PM): the thing is i am reading about a perfect rectifier
TF (12:20:55 PM): so i am trying to find out how to get its maximum frequency
delabs (12:21:14 PM): ok
delabs (12:22:02 PM): you mean precision rectifier
TF (12:48:56 PM): are u there sir
delabs (12:49:17 PM): national.com/mpf/LF/LF353.html
delabs (12:49:03 PM): These devices are low cost, high speed, dual JFET input operational amplifiers with an internally trimmed input offset voltage. They require low supply current yet maintain a large gain bandwidth product and fast slew rate. In addition, well matched high voltage JFET input devices provide very low input bias and offset currents. The LF353 is pin compatible with the standard LM1558 allowing designers to immediately upgrade the overall performance of existing LM1558 and LM358 designs. These amplifiers may be used in applications such as high speed integrators, fast D/A converters, sample and hold circuits and many other circuits requiring low input offset voltage, low input bias current, high input impedance, high slew rate and wide bandwidth.
delabs (12:50:16 PM): Characteristics of Operational Amplifiers
TF (12:52:03 PM): checking
TF (12:52:26 PM): i think slew rate would be the parameter
delabs (12:52:42 PM): great, you got it