I'm available for projects

Try also Criminal Case on Facebook. :D

Michael

How about writing that book I've been bugging you about?

Cheers

Phil Hobbs

I ponder that, but I'm not sure I'd be good at writing... circuit design is so easy for me I'm not sure I can explain how I do it ;-) ...Jim Thompson

Do you freeze when walking, then frantically start drawing in the dirt with a stick, like this poor Croatian did? :D

Michael

Worse... I dream circuits and wake myself up, then can't get back to sleep ;-) ...Jim Thompson

As long as the circuit isn't lost, it's a gain, right?

Sometimes I would dream of music in my sleep, wake up, and want to write the notes down, but in the transition to wakefulness they're lost :p

Michael

Start with some examples, and write them as you go along. I find that writing or rewriting sections when I'm actually doing the task described improves them greatly.

Cheers

Phil Hobbs

In the mid 1980s, Roland had International Rectifier design a custom chip called the IR3R05 for their analog synthesisers. I think it was a 14 pin package...it basically consisted of 4 OTA stages like the Lm13700 configured as a 24 db/octave resonant low pass filter with inputs for voltage controlled frequency and resonance, along with a VCA with both linear and exponential inputs, all on the chip. The 4 filter capacitors were mounted off chip on the board.

What kind of job would it be to design a chip or maybe a daughterboard that performed an equivalent function? These chips often fail in vintage equipment and there seems to be a decent sized market for replacements that dont require scrounging for NOS or cannibalizing old units.

I'm sure I could replicate the chip, but I don't do PCB layout, that's another skillset altogether. ...Jim Thompson

Yep. I developed a behavioral model extension for OpAmp parameters in my sleep this week ;-) ...Jim Thompson

Good thing I've got that skillset. ; )

I wonder it the required components could be squeezed into a daughterboard that would fit the space available. Might require some vertical mounting hack.

Jim, go buy a fishing pole.

That would rather involve water. Jim lives in the outskirts of Phoenix.

Cheers

Phil Hobbs

He's got time to take a ride. I think you got the gist of my comment.

Or, perhaps, a .300 Win Mag?

Michael

You have a granddaughter with that circuit lab kit. Eventually you will explain things. Just think about how you will do that.

Or occupy your time by riding a bike over the Himalayas like Pease did.

Grand_son_... 8 years old... the same one who's on the All Star Inline Hockey Team and was just awarded a trophy for best defensive player of the whole league ;-) ...Jim Thompson

Well then just pretend that he's going to be an engineer and not a goalie.

He's super with math, and loves the circuit lab upgrade I gave him at Christmas. But he's struggling with reading... a bit of dyslexia... time to hire a tutor (I would do it, but he needs an authoritarian type to keep him from deviating from work and controlling the conversation... he's a charmer... seeks out the girls in the crowd... and he's only 8 ;-) ...Jim Thompson