Old magazine series 99 IC projects

[bertus]

Hello,

I have found a series of old 99 IC projects magazines on the Internet Archive:
https://archive.org/details/99ICProjects1979
https://archive.org/details/99ICProjects1980
https://archive.org/details/99ICProjects1981
https://archive.org/details/99ICProjects1982
https://archive.org/details/99ICProjects1984

Bertus

 

[ratstar]

In the 1979 one, I see a gizmo for a bar graph, and someone needed one for his water tank not long ago. =)

It works with a strange technique of dropping voltage through diodes, but I dont see how it works entirely. Its actually an ADC! but you need one bar per bit, not one bit per power of 2 of the result, goes to show if all you need is 8 bit resolution ADCs sample as fast as you want, as long as you put the full 256 lines down.

 

[bertus]

Hello,

Did you read the text of the led bar graph?

When turning up the voltage, led 6 will be on first, then about 0.7 volts higher led 5 will turn on etc.

Bertus

 

[ratstar]

I see, I was thinking it was a current dependant input! i see now. cool.
You can exchange the diodes for voltage dividers, if your short on semiconductors.

So does that mean you just put a current divider instead of a voltage divider you get the current version!?

 

[Nanren888]

It works with a strange technique of dropping voltage through diodes, but I dont see how it works entirely. Its actually an ADC! but you need one bar per bit, not one bit per power of 2 of the result, goes to show if all you need is 8 bit resolution ADCs sample as fast as you want, as long as you put the full 256 lines down.

Diodes used to set voltage thresholds is not an uncommon technique.
Here it would give a soft turn on, for each LED, I guess.
.
256?, OK with 256 LEDs, maybe 32,768 diodes, about 150 volts and 256 resistors, ratings for that voltage & quiite a lot of current.

 

[ratstar]

256?, OK with 256 LEDs, maybe 32,768 diodes, about 150 volts and 256 resistors, ratings for that voltage & quiite a lot of current.

Pure Parallel does increase power requirements - but it would potentially give you sub pico-second sampling, if you handled all the other problems, which I'm not aware of yet.

 

[Harald Kapp]

Study "flash ADC".

 

[TCSC47]

Love these 99 cct books and others like them. When I was an apprentice and we were being taught valves (It was the 60s!) I got hold of a Practical Wireless, cct pocket booklet. I spent a lot of my time knocking up the transistor ccts and learning from them. Didn't get very good marks from my supervisors, but I found I knew a lot more about transistors than any of my apprentice colleagues.

 

[ratstar]

Didn't get very good marks from my supervisors

Maybe they were jealous.

 

[bertus]

Hello,

@TCSC47 , You might want to have a look at this page for some old books:
https://worldradiohistory.com/BOOKSHELF-ARH/Bookshelf_Hobbyist.htm
There are also many "specials" on the same site:
https://worldradiohistory.com/Hobbyist_Special_Editions.htm

Bertus

 

[TCSC47]

Maybe they were jealous.

No, I just didn't realise that I was supposed to do as I was asked to! You get wallys like me everywhere! Lol! Took me a while to figure this out. Mind you it enabled me to walk straight into a job after my apprenticeship.

 

[TCSC47]

Hello,

@TCSC47 , You might want to have a look at this page for some old books:
https://worldradiohistory.com/BOOKSHELF-ARH/Bookshelf_Hobbyist.htm
There are also many "specials" on the same site:
https://worldradiohistory.com/Hobbyist_Special_Editions.htm

Bertus

Cheers.