robotmaker
I design alot of circuils been electronic engineer and was look at are using using switching transistors to turn on lights ,relays and more
Transistors are mostly old school design ,before mosfets came out,if you look at the h-bridges now that use mostfets instead of transisors
For a few reasons one is low RDS on ,with meens they can handle higher wattage and not get hot using transistors ,plus less voltage
The most common is n-channel and have 3 pins ,GATE witch goes to digital output with a current drive resistor then SOURCE witch is the load and DRAIN is ground
Now for protection for mosfets most have a diode that protect it from EMF or inductive kickback
MOST i see use diode on transistors from collector to emitter ,NOT a good idea manly it does suppress or stop the inductive kickback and if using a microprocessor or circuits with will get resets and more induce in th system
so where the diode goes is always across the coil with cathode (black line ) to postive and NO inductive kickback
DIODES are only needed for inductive loads ,motors and relays or coils
Not for resistance loads ,lights or heaters ,leds will put up a simple circuit
second part will be how to control AC products,RELAYS are also not good slow switching and as noises on the contacts that does resets but wull give info on how to fix them
HOPE this is easy to understand if not just ask a question
Also DAVE can i ask the same question to you about what school or college you went to ? And RICH if he cares to answer it.
Woops, sorry. Didn't mean to misspell your name. should have been Fred and not ferd.
I was at Texas A&M for only a short while. No degree. I learned most of what I know in the school of hard knocks.
I know you didnt misspell my name,seems i am not the only one that doesnt use spell check
Some of my friends playing with me call me FERD,EVEN MY GIRLFRIEND TOO.
IT seems on this forum people without a degree knows more then ones with a degree,that not right.
IT like saying the student knows more then the teacher.
I am on many many electronic forums this is only one thats like that.
DAVE i did enjoy college alot,but i love my work alot better,free travel ,my own room with a pretty secretary and pay was more then i ever need.
But now working at home as a freelance engineer for the company ,is much better
PLUS i get to check all the parts and most of the test equipment when i retire early in under 2 weeks
Only thing bad is going to miss my pretty secretary,but my girlfriend will be there and soon getting MARRIED to her.
Fred, I've often known more than the teacher - that was my main problem in school, why I didn't like it, it wasn't challenging at all and very boring... I did poorly in school and had to bluff my way on to the courses I took afterwards. Some qualifications I hold have prerequisites that I don't actually have which shouldn't happen. When I took my AutoCAD course I knew more than the teacher and ended up teaching him a thing or two... Similar when I was an apprentice electrician. It doesn't really say much about the teachers!.. But then I do have a natural ability to pick things up almost instantly (proven by only using ARC for less than 3 months and being on these forums for 4 months).
My training has been at various places. Mainly at the technical college in my county, which no longer exists. Some has been online, some has been in the class room, some has been home study, some has been self taught by just doing.
YEP i thought that,student know more then the teacher,how come you dont have a degree.
teacher in college is professor and has the highest degree.
i also pass the course and i am licensed electrician
I GUESS you think teachers are not needed
ON teachers they get there degree from a college professor. So teachers dont know that much.
in high school i had a very high IQ most then most in my class,and was a sub teacher for a few hors on science ,where every year i has straight A'S
I don't have a degree for a few reasons;
And for the record I don't think I got a single A in school, grades mean nothing.