And now for something a bit different

Majorman · Jun 11, 2022

But still with farming connections. This is one of the circuit boards I designed and built to control depth/height of carrot and parsnip toppers, potato defoliators, depth control on potato and sugar beet harvesters and other machines. They go world wide on machines and we have built a few hundred of them. Not large quantities but there are no really large numbers in agriculture when it comes to speciality designs.

Enjoy the puzzle!

Brian
Board

MarkB_MI · Jun 11, 2022

Hmm. Analog!

Geo-TH,In · Jun 11, 2022

Mark,

This is my latest puzzle.
I didn't design it.
Its for my AC.

It's a head scratcher.
Going to town to buy a new one.

A lot of diodes, capacitors, resistors and one fan relay. Something's eating the 3a fuse

Geo-TH,In · Jun 11, 2022

Majorman
I didn't know you were a sparky, electrical engineer.
I know enough about electricity to be dangerous..dangerous to myself.

M-MAN · Jun 11, 2022

The fuse is there to protect the board not the other way around. I suppose it could be bad but I never had it happen. It was always a wire shorting or a bad component blowing the fuse. Not fun finding it.

Tgrasher · Jun 11, 2022

Amazing, especially since I haven't a clue how in the world these boards work. I have found that it is less expensive to fix problems like Geo's myself as the repairman doesn't seem to know much more than me.

Majorman · Jun 11, 2022

Hi George, not a sparky as such, got into circuit design by the back door, doing electrics on Ford tractors as part of the job then, with an ex-RAF Radar chap, invented and patented a system for forward speed control of combine harvesters relating to the load on the working parts and the grain losses from the separation mechanism.

Majorman · Jun 11, 2022

Hi Mark, yes, I am a great believer there is still a place for analog circuits in the modern day. I am known for producing circuits that withstand very harsh conditions and keep working for many years. We do do some digital units but I still find that analog can be repaired without too many special tools, in the field (literally). And in a lot of cases, the parts can be cheaper too.

db4600 · Jun 11, 2022

I was expecting John Cleese!

John T · Jun 11, 2022

Nice lookin board. Ive owned RV's fifty years and the darn control circuit boards used on the furnaces, water heaters and fridges ARE NOTORIOUS FOR FAILURES grrrrrrrrrrrr and even being an electrical engineer no way Im fixing them. There is one company Dinosaur Electronics that makes replacement boards and so far NONE of them have failed..

Best wishes

John T

MountainGoat · Jun 11, 2022

I admire your adherence to through-hole. That's where I cut my teeth in the 80's. And, I actually believe you that there is availability. In the SMT world it is opposite right now and has been for the last two years. 52 week+ lead times on many things. I find myself buying parts from some guy in Taiwan (Vincent, if that's his real name...) in a back alley with a trench coat that has fake Rolex's on the other side. Currently I am reviving my Boonton 1120 Audio Analyzer so I can characterize vacuum tubes as that market has also exploded and hoarding is finally going to pay off.

MountainGoat · Jun 11, 2022

Find your model online and get the manual. It will have the circuit in it. Popping a fuse is usually something downstream. You need to figure out what that part is. Could be on the same board, could be external.

Geo-TH,In · Jun 11, 2022

Sparky or not.
There are educated EET or OJT EET. Designing a PC requires some training..
I'm a physics and math major. I took every class I could in electronics. I even took a correspondent course to learn how to repair TV's when TV's were Tubes.

The circuits I've designed are old school, not PCs.

oldsarge · Jun 11, 2022

Bell & Howell Schools with Radio Shack kits?????????????

Roger Tomfohrde · Jun 11, 2022

Janicholson · Jun 11, 2022

Beautiful discrete circuit board. nicw two output design. I like it. Jim

Steve@Advance · Jun 11, 2022

That's quite an accomplishment!

chcase · Jun 11, 2022

I tip my hat to you for being able to design these boards.Just wish industry wide would design things that could be fixed and not just replace.

Tony in SD · Jun 11, 2022

Nice job. In a former life I designed multiple circuits for mostly one of a kind functions. They are sometimes a head scratcher, hard work, but rewarding when you get them to work the way you want.

Geo-TH,In · Jun 11, 2022

Most of what I know came frome from experiences, OJT.
Mixed with book Theory.
I also taught high school electronics for 31 years.
A lot of hands on.

37 chief · Jun 11, 2022

Those circuit boards made me a good steady living. I worked for the Burroughs computer company (now Unisys) for 36 years. The company made circuit boards by the thousands, for the computers they made. Now mostly computer chips take place of the circuit boards. Stan

And now for something a bit different

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