Fun with analogue multipliers

Better to spend your energy offending people.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

OK, you use two integrators to make the oscillator, and can then compute sin^2+cos^2 to get the amplitide. That's very clever but the circuit details might be better.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

It's hard not to offend people who post nonsense then expect to be praised for making the effort.

I suppose that there might be ways of doing it diplomatically, but people who publish nonsense are rather resistant to the proposition that their ideas a less than admirable. It takes a fairly explicit criticism to crack the armour of self-delusion.

I did put in years (from about 2011) responding to any job ad on the local Seek web-site that I could reasonably imagine getting. I did get a few interviews early on, but no job offers, and even that dried up.

Tough. You get it anyway.

Not in my experience. You get ripple from all over. And nulling the offset on the both the x- and y-inputs of a four-quadrant multiplier is tedious. I had a procedure that seemed to work for me, but final test couldn't get it to work so we just paid for a laser-trimmer AD multiplier. The extra cost wasn't much higher than cost of working through the procedure, even if you could do it as fast as I could, and final test couldn't seem to make it work at all. If we'd persisted we might have got it to work, but we had better things to do.

Interviews without offers. Why?

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

I thought you said you weren't going to look at my circuit? Gravol may help.

Get some rest. There's no need to be up all night at your age. And I'm aware that I can't possibly do anything as good or as fast as you can.

Originally I was using a Wein bridge oscillator but circuits posted by JM and also the information on this page made it clear that state variable is a better idea.

There are plenty of people way more clever than me.

If you have any suggestion for improvement I'm all ears.

_Wien_. It's a Wien bridge. Named after its inventor, Max Wien.

Jeroen Belleman

That hit me after I posted. I was hoping no-one would notice.

Google translate says it means Vienna.

Is Veen the correct pronunciation of Wien for an English speaker?

I just use a Microchip PIC or FPGA and a sine lookup table and R2R DAC.

Or if running Linux on my Raspberry Pi 'sox' to make a nice sine wave file?  Search Assist To create a sine wave file using Sox, you can use the command: sox -n -r 44100 -c 1 sine_wave.wav synth 3 sine 500.

This command generates a 3-second sine wave at 500 Hz and saves it as "sine_wave.wav

John Larkin has looked in enough detail to save me the trouble.

Since I sleep through most of the day, I'm actually compensating for the time difference between Australia and the rest of the world. I am working on getting to bed earlier, but with limited success.

Your electronic design skills aren't impressive,but neither were those of a lot of my colleagues when I was working, and they still did useful work, even though I sometimes had to clean up after them. Good enough doesn't have to be all that good.

I think they wanted to be able to say that they had interviewed an elderly person - I was in my 70's by then - but I would have needed to be exactly what they wanted to get hired.

One of the downsides of having specialised skills is that there aren't that many employers around who need them, and even fewer who know what they actually need.

I did get interviewed at Lucas Heights for a job on Australia's only nuclear reactor. They were thinking about upgrading the neutron diffraction set-up, which they'd bought from a French group at Grenoble some thirty years earlier. They were probably in-house candidates with more relevant experience. Fun interview, but no job.

I think electronics is fun. You think it's trouble.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

I enjoy getting it right. You seem to settle for getting it good enough to sell.

No-one cares Bill. Like John Larkin I'm just having fun. I'd have to admit to finding it amusing watching you go red faced over nothing.

If I wanted to assemble a team to look after a nuclear reactor then I'd want a team of people with characteristics similar to many of the people who regularly post here. But I wouldn't let you anywhere near either the team or the reactor for reasons which have nothing to do with any kind of technical skills whatsoever. Age would also not be a factor.

It's difficult to detect facial coloration in a text-only user group. I'm sure that your imagination is up to inventing images that make you happy, but it's all self-delusion.

The job wasn't looking after any part of a nuclear reactor. It was about developing a new neutron diffraction facility - some nuclear reactors are used as neutron sources.

It was a development job, not maintenance. And I imagine your ideas about desirable personality types for the job are about as well founded as your ideas about what the job would have involved.

No-one cares Bill.

No-one cares Bill.

So why do you bother posting your delusions here?

You cared enough to post your own delusions about how you'd staff the job you imagined I'd been interviewed for. You do rate as a nobody, but a noisy one.