Design a Coil for a Specific Inductance

YouTuber [RimstarOrg] shows how to make a DIY inductor for a specific inductance. This is obviously a great skill to learn as sometimes your design may call for a very accurate inductance that may be hard to find otherwise.

It may seem daunting when it comes to making your own inductor you may have a few questions such as: What type of core will I use?, How many turns does my coil need? or How do I calculate these parameters to create the specific inductance I desire? [RimstarOrg] goes through all of This, he even has a handy Inductance calculator  …read more http://pje.fyi/PLp3DC

Paul Jacob Evans

A Few of Our Favorite Chips: 4051 Analog Mux

Raindrops on roses, and whiskers on kittens? They’re alright, I suppose. But when it comes down to it, I’d probably rather have a bunch of 4051, 4052, and 4053 analog multiplexers on the component shelf. Why? Because the ability to switch analog signals around, routing them at will, under control of a microcontroller is tremendously powerful.

Whether you want to read a capacitive-sensing keyboard or just switch among audio signals, nothing beats a mux! Read on and see if you agree.

The Basics

An ideal analog multiplexer routes a single common pin on one side through multiple switches to multiple …read more http://pje.fyi/PB90zX

Paul Jacob Evans

Reusing A Wire Bonded Chip

We will all at some point have opened up a device to investigate its internal workings, and encountered a blob of resin on the PCB concealing an integrated circuit. It’s usually a cost thing, the manufacturer has sourced the chip as bare silicon rather than in encapsulated form, and it has been bonded to the board with its connections made directly using fine wires. The whole fragile component is then hidden by a protective layer of resin.

Normally these chips are off-limits to we experimenters because they can not be removed from the board without damage, and we have no …read more http://pje.fyi/P9GFKK

Paul Jacob Evans

Afroman Makes A UHF Oscillator From A Potato

If you have ever worked with simple logic gates, there is a good chance that at some point you will have built a ring oscillator from a chain of inverters. With the addition of a resistor and a capacitor, you can easily make a square wave oscillator up into the megahertz range with standard logic chips.

[Afroman] received some rather special logic chips, from an unexpectedly named company, Potato Semiconductor. They specialise in making versions of common 74 series logic that smash the usual 100+ MHz barrier of the faster conventional 74 series chips, and extend their bandwidth up to …read more http://pje.fyi/P1s941

Paul Jacob Evans

Negative Resistance: It Shouldn’t Make Sense!

When you leaf through a basic electronics textbook, you’ll find chapters describing in detail the operation of the various components. Resistors, capacitors, inductors, and semiconductors. The latter chapter will talk about P and N type regions, introduce us to the diode, and then deal with the transistor: its basic operation, how to bias it, and the like.

Particularly if your textbook is a little older, you may find a short section talking about the tunnel diode. There will be an odd-looking circuit that seems to make no sense at all, an amplifier formed from just a forward-biased diode and a …read more http://pje.fyi/Njzpjw

Paul Jacob Evans