Little Nemo in Slumberland: Reconciling interests

At the moment I am continuing to work on the subject of operational amplifiers.

And as is the case in the almost infinite world of electronics, there are also almost endless questions to ask and research.

You quickly find yourself in a specialty and the question is whether it wouldn't be wiser to keep your interests broad.

Because what you learn quickly gathers dust and if, like me, you have three main areas of interest, namely camera repair, electronics and math, it becomes an organizational task.



Follow too many activities and you end up like
Little Nemo in Slumberland


So I'm trying to pursue camera electronics as my main topic and to work more on this in order to better understand the processes in my cameras from the 1980s.

Then repairs make more sense and are more fun because I know more about my patients.

And there is always something to calculate in electronics, so the subject of mathematics also remains current.

But with mathematics, what you need from it for specialized electronics calculations is only a small part.

All the arithmetic with terms, simplifications, transformations is absolutely oversized for what I need for my circuit calculations.

And doing mathematics for mathematics' sake would require a second life.

How do you deal with maintaining and developing your interests?

Is camera electronics a real issue? What I mean:

• Either you have a "naïve" camera where the electronics is just a series connection of sensor, galvanometer, maybe one or two resistors, and a battery (if the sensor is a photoresistor). Not rocket science.
• Or there is a microprocessor. If you are lucky, the pin assignments are documented in a service manual, but the code remains hidden in some ROM. You can still perform continuity checks, and for that the most basic electricity skills are enough.

I found my electronics knowledge (however limited) more useful in repairs of audio equipment.

Many cameras from the mid 70's and before the microprocessor would have op amp circuit as well as logarithmic amplifier. The ones with resistors etc.. were those with CdS cells. With silicon you do need ampifier and especially log amp.

bernard_L said:

Is camera electronics a real issue? What I mean:

• Either you have a "naïve" camera where the electronics is just a series connection of sensor, galvanometer, maybe one or two resistors, and a battery (if the sensor is a photoresistor). Not rocket science.
• Or there is a microprocessor. If you are lucky, the pin assignments are documented in a service manual, but the code remains hidden in some ROM. You can still perform continuity checks, and for that the most basic electricity skills are enough.

I found my electronics knowledge (however limited) more useful in repairs of audio equipment.

Click to expand...

My cameras are in between, a combination of analogue and digital electronics, already with microprocessor (Nikon F3, Minolta X).

Ironically, I think electronics theory has been most useful to me when servicing older cameras which have very simple circuits consisting of resistors, photocells and galvanometers! For instance, some older circuits were designed for 1.35 volt mercury batteries, but I may wish to power them with something more modern, or I may need to replace a photocell which has unknown parameters.

Interesting (to me, anyway) side note: The other year, I acquired a Ricoh Auto Half, which was originally equipped with a selenium photovoltaic cell, but that part had failed. Have you ever tried to find a datasheet for a selenium cell? I eventually found something from Tandy / Radio Shack, but was that part comparable to the original Ricoh part in terms of spectral sensitivity, output, etc? I didn't have a clue. But very roughly speaking, it appeared to me that when comparing a modern crystalline silicon photovoltaic cell with a legacy selenium cell having similar dimensions, output voltages were similar, but with the modern cell delivering a whopping 10x as much amperage. Which suggested that I could get away with using a silicon cell which was just a fraction of the size of the old selenium cell. And what do you know, it worked. I don't have a calibration-standard light source to refer to (and wouldn't have a clue what Ricoh originally used), but my color negative film seemed properly exposed, and that was good enough for me. And unless physically damaged, crystalline silicon PV cells last a very long time.

But applying electronics theory when servicing more modern electronic cameras? Not so much: The operating parameters have already been decided, so my job is reduced to looking for components prone to failing over time, which usually means capacitors and cracked plastics.

Although there can be enjoyment in learning electronics for it's own sake, I seem to learn better if I have practical applications for my knowledge. Sometimes I just want to take photos, and I'm learning to appreciate film cameras which are easy to maintain.