JamesBryant

You can find all the RAQ (Rarely Asked Questions) at:- https://www.analog.com/en/analog-dialogue/raqs/raq-issue-xxx...

Where xxx (or xx or x - no leading zeros) is the number. Highest is presently 190. I wrote all the first ones, then I shared slots, and after I retired I just wrote the occasional one.

It was correct when I wrote the RAQ in 2007.

In fact I've been making the crack about 'not being able to change it because he's dead' in my lectures for at least forty years.

But don't waste time reinventing the wheel. I needed a small audio amplifier the other day and looked for an IC to build it. My junk box was empty of audio amplifiers so I went to a distributor and found a nice IC for 65p but minimum order 10 off. With postage the price was about £10, and I still had to find the other components and build it.

I was just about to order it when I realised it might be cheaper on eBay. There a found an assembled board with the same amplifier for 56p with a minimum order of 5 pieces:- £2.80 post paid and ready to use - and four spare ready-made amps for future projects.

Beating the system is fun, too.

Not quite - what I meant was build it from whatever you need in the simplest way that does what you need. That may be just discrete components, or it may be a handful of ICs, or a mixture. And don't overlook the possibilities of embedding a minimal microcontroller to do any logic - it may be the smallest, cheapest, simplest solution.

And the other half of the message was to build it as a well-defined entity which can be proved by itself before it is used in its final application.