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Saturday, April 06, 2019

Dual Differential Amp - Op-Amp Designs

The Input Impedance of this module is very high and is symmetric. This circuit can be used for strain gauges and for four wire measurements. If inputs are in mV use OP07. The merit is that it uses only 2 OpAmps yet has high differential Input Impedance.

Dual Differential Amp - Op-Amp Designs

Dual Differential Amp - Op-Amp Designs

The Outputs of Opamps are low impedance but still have limits they cannot drive more than a few mA of Current into the Load. If low ohmic value loads are to be applied use external transistors as amplifiers. If inputs Vn-Vp are floating, outputs may be random or oscillating, it is good to have a bias network of 10M resistors to a potential even zero or common, this enables some Vout when input floats.

Astable Multivibrator with 555

This is a demo of the popular 555 timer. you can try out the project on this page by a javascript simulation. Press the Red button below to turn on the circuit press it again to turn off. The 555 can source (LED2) or Sink (LED1) upto 200mA.  If you are starting with electronics, this is the first step. So do it now ! Do-It-Yourself.

Screenshot of Astable 555 Timer Flasher

It can even drive a small motor or lamp with diodes added to protect from inductive kickback.Vary Ra, Rb and Ct with the controls given and see the change of frequency, period and duty cycle.

Screenshot

Astable Multivibrator with 555

These are the formulae used by 555 and same is used in javascript without any change.

Monday, April 01, 2019

Mass Spectrometry and Portable Microbe Detector

Human Beings are helped or hampered by many types of Microbes. From the Sub-Microbe virus to animal like Bacterium and plant like Fungi.

An Affordable Portable Electronic Microbe Detector using Mass Spectrometry; may be very useful for Small HealthCare Centers and Homes. If a Person Breathes into an adapter in the instrument, it should show a simple analysis of the Air Microbe Levels. It can also be used for CleanRoom Air Purity Indication.

Mass Spectrometry and Portable Microbe Detector

This is just an idea for an urgent need, this may prevent spread of flu to escalate into an epidemic; due to early detection of microbe, at the root, in every home.

Here are some Mass Spectrometry Resources that students can study and attempt to research to Develop a cost-effective consumer flu-detection device.

Ideas of delabs - 2004- First posted in my blog Analytical Bionics.

Learn more about the Subject Basics