Electrical Theory Help

[Chotu]

Originally Posted by R Hutcheson

Thank you everyone. The missing piece was how to calculate the voltage drop over individual resistors. I have it now.

Thanks again.

Congrats!!

[BocaIII]

even as an a graduate electrical engineer i found this book very helpful

https://www.amazon.com/12-Volt-Bible...1-844de3f06670

capt jack

[Ike]

Originally Posted by thomm225

Thanks for posting this.

Our tech's these days spend so little time on electrical circuits due to all the computer hardware, software, and cyber they need to learn.

Thousands of pages to study for each with a small amount of time spent on old school electronics.

But it's best to learn to troubleshoot.

And that would be hard for me to explain because first you might need a few years of theory then lots of problems to solve to learn best

Just remember though, most of the time electrical problems on a sailboat are rarely due to failed circuits but usually corrosion of some sort so a reseat/cleaning of a connection 9 times out of 10 will fix the problem.

And that applies to any boat. I have a basic electricity course on my web site but i deliberately left all this troubleshooting individual circuits out of it. If you are troubleshooting an old radio, or TV, or any electronics much over 30 years old then it would be useful. But on most boats you would be better off learning how to size wires to the circuit load, how to size fuse or circuit breakers.

The Coast Guard sent me to the Navy Electronics course back in 1966, and we spent most of our time learning all of that, analyzing circuits. It was good because most of the stuff I worked on had been installed in WWII. But on the newer ships, everything was controlled and analyzed by computers, and all you had to do was isolate it to a circuit board and change it out. Literally plug and play. No circuit analysis needed.

Anyhow, if you want to learn it that's ok, knowledge is always it's own reward. But on a small craft you will probably never use it. Most small boats under 25 o 26 feet only have a DC 12V system. Bigger than that they may have 12V DC and 120V AC. But still most problems are due to corrosion, or overloaded circuits. Both of which you can actually see visually. Bad grounds are usually the culprit, due to corrosion. Hot wires due to high resistance, caused by corrosion. One of the key ways to keep things working smoothly is to do an annual check of all connections in your system, clean them and reconnect them. Your most valuable tools will be a multimeter, a polarity tester, and lots of sandpaper. You might also want to buy some electrical contact cleaner.

[thomm225]

Originally Posted by Ike

And that applies to any boat. I have a basic electricity course on my web site but i deliberately left all this troubleshooting individual circuits out of it. If you are troubleshooting an old radio, or TV, or any electronics much over 30 years old then it would be useful. But on most boats you would be better off learning how to size wires to the circuit load, how to size fuse or circuit breakers.

The Coast Guard sent me to the Navy Electronics course back in 1966, and we spent most of our time learning all of that, analyzing circuits. It was good because most of the stuff I worked on had been installed in WWII. But on the newer ships, everything was controlled and analyzed by computers, and all you had to do was isolate it to a circuit board and change it out. Literally plug and play. No circuit analysis needed.

Anyhow, if you want to learn it that's ok, knowledge is always it's own reward. But on a small craft you will probably never use it. Most small boats under 25 o 26 feet only have a DC 12V system. Bigger than that they may have 12V DC and 120V AC. But still most problems are due to corrosion, or overloaded circuits. Both of which you can actually see visually. Bad grounds are usually the culprit, due to corrosion. Hot wires due to high resistance, caused by corrosion. One of the key ways to keep things working smoothly is to do an annual check of all connections in your system, clean them and reconnect them. Your most valuable tools will be a multimeter, a polarity tester, and lots of sandpaper. You might also want to buy some electrical contact cleaner.

Right!

I did the basic electronics twice.

Back in the 70's, if you extended or reenlisted you were sent to a "C" School or Career Class and redid everything from the math on up.

I extended 14 months and was out in 5 years total but got tons of electronics training.

2.5 years of school and in a military school it's 8 hours a day not like college at maybe 4-5 hours/day a few times a week with a couple semesters per year. (I majored in History in college and that was the schedule then)

It was 8 hours because you are being paid to learn plus stand duty, etc., etc.

I learned 4 different radar systems (ASR/PAR) and one IFF which we covered every page in the schematic pack line by line then they put problems in the systems like open resistors, shorted cap's, dip chips with one leg cut off so we then did weeks of troubleshooting. (and no more theory)

We troubleshot live circuits with an O'Scope and and unenergized circuits with a meter (per George Stanley Hewlett Packard Engineer via his circuit analysis films ) We had a full schematic pack for the whole system.

Later learned the ACLS system that landed planes on carriers. The computer had like 2 or 4 8K , yes 8 K memory cores and we loaded that computer a Sperry Univac with Mylar tape.

In the 1980's, we loaded our IFF simulation computer with paper tape. It was a Nova 1200 or 1210.

I was a Marine Tech not Marine Infantry/Grunt so after boot camp it was straight to a Navy Tech School.

First computer class was 1982.

Back then there was no GUI. You did all commands in BCD octal in the computer I learned on a UYK-20.

Later we ran the thing from the command line prompt then finally GUI by 1995 or so.

[Ike]

Actually I fudged a little. I was a Fire Control Technician (FT). But these days when you say Fire Control people think you are a fire fighter. So I just tell them I was an electronics tech, and leave out all the stuff about ballistics and weaponry, guided missiles, computers, gunsights and such. Of course mostly we still had analog computers which were half electrical and half mechanical. The Missile FTs actually got to use digital computers, big things that took up a whole room. Us gun fire types were only allowed to look at them.

The school was at Mare Island, Vallejo, CA.

The newer cutters had more modern systems with real digital computers. The radar I worked on was from WWII and only had ranging. You had to read the bearing and elevation angle off a monitor connected to the Director and then crank that by hand into the mechanical computer which gave you a target solution. Primitive, but it worked. It was good for shore bombardment, and slow moving target like ships and prop aircraft. No good whatsoever against jets.

I didn't get into digital computers until the 70's when I took my first FORTRAN course, and had to do inputs to big IBM's. What a world! Now it can all be done on your phone!

But in 1976 I went to Officer Candidate School and left most of that behind. I went on to Engineering.

I apologize, I didn't mean to hijack the thread.

[thomm225]

Originally Posted by Ike

Actually I fudged a little. I was a Fire Control Technician (FT). But these days when you say Fire Control people think you are a fire fighter. So I just tell them I was an electronics tech, and leave out all the stuff about ballistics and weaponry, guided missiles, computers, gunsights and such. Of course mostly we still had analog computers which were half electrical and half mechanical. The Missile FTs actually got to use digital computers, big things that took up a whole room. Us gun fire types were only allowed to look at them.

The school was at Mare Island, Vallejo, CA.

The newer cutters had more modern systems with real digital computers. The radar I worked on was from WWII and only had ranging. You had to read the bearing and elevation angle off a monitor connected to the Director and then crank that by hand into the mechanical computer which gave you a target solution. Primitive, but it worked. It was good for shore bombardment, and slow moving target like ships and prop aircraft. No good whatsoever against jets.

I didn't get into digital computers until the 70's when I took my first FORTRAN course, and had to do inputs to big IBM's. What a world! Now it can all be done on your phone!

But in 1976 I went to Officer Candidate School and left most of that behind. I went on to Engineering.

I apologize, I didn't mean to hijack the thread.

I'm like 10 years after you.

I think they did away with the FT Rate.

I have mostly ET's and AT's on my staff of techs from the Navy these day.

Air Force and Army are different but now all our Tech's including me the Manager have to have a Comptia Certification of either A+, Network +, or Security +.

All Cyber Security Techs have to have at a minimum Security or Sec + and the Operating System (OS) Cert for the Systems we have which usually are Linux (Redhat), Windows 10 or 11

[Ike]

The Coast Guard did the same. It's all handled by IT people and ETs, and Contractors. If it breaks, pull it out, replace it, send the broken one to the contractor.

[thomm225]

Originally Posted by Ike

The Coast Guard did the same. It's all handled by IT people and ETs, and Contractors. If it breaks, pull it out, replace it, send the broken one to the contractor.

Yep.

Our techs actually replaced a couple switches recently so the soldering irons were able to burn the dust off of themselves

I just removed another O'Scope from our Calibration list. No need to pay $340 to have it recalibrated.

We have two O'scopes left that are Calibrated. One has been used in the last 4 years.

I just sent in all 4 of our Fluke 87's or 87 III's for calibration. Hopefully we won't need them. They get used maybe a couple times/month.

We have 14 systems. Flight Simulators or Tech Training Simulators.

The Flight Sim's have 10 projectors and the cockpits have Aircraft Common Equipment (ACE) so the pilots can get familiar with the real thing. Same for the NFO's in CIC.

We have 100's of computers on various networks. Large UPS Units for every system with anywhere from 32-72 12 volt batteries in each.

Most repairs consist of reboots, small software fixes or resetting a MAC Address or IP Address. Sometimes a reseat.

[HabibiDah]

I love this stuff! I actually have a master's in Electrical Engineering and taught circuit analysis at a university. Nodal and mesh analysis are like playing sudoku. It's a fun game. (ok...maybe I'm a geek.)

I love everyone's analysis and explanations. I thought basic circuit analysis was practically dead these days.

[thomm225]

Originally Posted by HabibiDah

I love this stuff! I actually have a master's in Electrical Engineering and taught circuit analysis at a university. Nodal and mesh analysis are like playing sudoku. It's a fun game. (ok...maybe I'm a geek.)

I love everyone's analysis and explanations. I thought basic circuit analysis was practically dead these days.

It is pretty much is dead.

It's almost skipped over entirely for most technicians. Maybe just touched on. We'd spend months on it back in the day.

I asked one of my sharp computer/Cyber Techs what he would do if he had no input power.

We use 3 phase input power through a UPS then to the Power Distribution Panels on all systems then different phases go to different chassis.

He said he would call Jim. Jim's an old navy ET. (ET is the navy rate for electronics tech)

It's really complicated these days. The techs need to kow all about the computer hardware/software, cyber security, and I also need enough electronics techs around to fix actual electrical/electronic problems.

These days though we have Phoenix I/O and it tells you if it has a failed Analog or Digital Output or Input module.

[Ike]

I asked one of my sharp computer/Cyber Techs what he would do if he had no input power.

The first thing we were taught was check the ON/OFF switch. If it has a power cord, is it plugged in?

I went on to other things, but one of my duties as a Coast Guard Civilian engineer (after I retired from Active duty) was participating in a lot of ABYC Project Technical Committee meetings, the primary one being the Electrical Systems PTC, an SAE electrical committee for ignition systems and a raft of committees on other than electrical.

Other than in the NAVY school, I have used an O scope once to troubleshoot a circuit. Anything else, a VOM was usually sufficient. That and I have a little device I can plug into any AC socket that tells me if it's good. It also indicates polarity. I got it free at an IBEX (exhibition) in Miami. Handy little thing. It was great on my RV for trouble shooting problems. Most electronic devices these days are very reliable and i is cheaper to buy a new one than to get someone to fix it.

[thomm225]

Originally Posted by Ike

The first thing we were taught was check the ON/OFF switch. If it has a power cord, is it plugged in?

I went on to other things, but one of my duties as a Coast Guard Civilian engineer (after I retired from Active duty) was participating in a lot of ABYC Project Technical Committee meetings, the primary one being the Electrical Systems PTC, an SAE electrical committee for ignition systems and a raft of committees on other than electrical.

Other than in the NAVY school, I have used an O scope once to troubleshoot a circuit. Anything else, a VOM was usually sufficient. That and I have a little device I can plug into any AC socket that tells me if it's good. It also indicates polarity. I got it free at an IBEX (exhibition) in Miami. Handy little thing. It was great on my RV for trouble shooting problems. Most electronic devices these days are very reliable and i is cheaper to buy a new one than to get someone to fix it.

Well it's a bit different than is it plugged in or is the on/off switch on with one of our systems with 3 phases coming in someplace in the building then going through a large UPS then to the power distribution panel/cabinet where most of the breakers are.

We also use 400 HZ on our systems so the three phases go to a 60/400 HZ converter also then to various other places. (single phases)

We once had one section of a triple three phase breaker fail so only two phases were getting through to the converter so it wouldn't power up. (but the breaker was on and not kicking)

But they do have that line in the Comptia A+ Computer Certification Book about the power cord and the On/Off switch if there is no power.

The other 900 pages in the A+ Book are mostly about computers, operating systems, ports, IP addresses, solid state drives, RAID Arrays, motherboards, CPU Chips, heatsinks, memory types, etc.

Then there's the Network + Cert, then Security + after that they need an OS Cert like Windows or Linux etc. so the point is there is so much more to learn these days that circuit analysis especially since computers show up everywhere even on our boats

Btw the cert after you get your OS can be a Cisco Switch Certification etc.

[deblen]

http://www.mojaladja.com/upload/Boat...l_Handbook.pdf


Wouldn't it be great if everyone who attempts boat wiring/electrical put as much effort into learning how,as OP is doing!

Great job,Mr H.

[thomm225]

Originally Posted by deblen

http://www.mojaladja.com/upload/Boat...l_Handbook.pdf


Wouldn't it be great if everyone who attempts boat wiring/electrical put as much effort into learning how,as OP is doing!

Great job,Mr H.

Yes it is great the OP is trying to learn electrical/electronic circuits, but it will take a while.

Then he will have to learn what young (or new ) techs have to learn and that is most times the problems encountered have absolutely nothing to do with the training you had.

99% of the time especially these days the problem will be a connection, improper setup, loss of IP Address, bad power supply, or you need to reboot/restart your system.

And on boats bad/corroded battery or shore power connections.

New techs just love to dive in and try to find a circuit problem, but rarely is the problem with a circuit.