Wow, thank you! I've been SEARCHING for this exact schematic for a while now. I've seen this circuit before and it's not too difficult to analyze. You can simulate it yourself using LTspice (from Linear Technologies). I couldn't quite remember it, but it's coming back now. I saw in a book called "Alternator Secrets" (more like a pamphlet) showing how this circuit works so that you can change the voltage to 120 volts to power your home. This video is GOLD!
3:00 Good point! Without the regulator cutting down the voltage to the rotor's field coil, the alternator's stator windings could produce up to 200v, which could burn out your vehicle's electrical devices.
I think the other way around, the T2 will turn off the T1 when the voltage at zener diode is high enough to turn on the T2 based on the voltage of the divider R2 & R3. The voltage at R1 is pulled to ground and that turns off the T1to cut the voltage in the field rotor coil.
A good explanation of the internals of an alternator is very hard to find. Lots of how-to's. Thank you very much for the explanation. I have been looking for a book that explains the detailed theory of how an alternator works but haven't found one. Would you happen to have any recommendations? I am a retired electronic tech.
@@marcosbecerrazarate8323 you can go to Google and just say the making a model of your car and you can download a free diagram the book is called automotive technology a systems approach
Thank you!! Been hunting for some proper illustration/explanation of how the voltage regulator works on an internally regulated alternator. I have a 1987 Honda CRX, and any diagrams I could find about the regulator simply had a box labeled 'Regulator' and no further description of how it works. Only other aspect that's still a mystery is the 'C' Terminal it has labeled. any description just says 'computer control' but no further explanation on the protocol used to control it (PWM, variable voltage, variable ground?) I suspect that ground brings it to low mode (12.8v) and float (left open) brings it to high mode (14.4v). Did find out, that pulling it high is a bad idea (cause that broke my regulator and had to replace it)
Very good! I would like to know how (in the second diagram) the lamp gets its mass when alternator is not functioning; is that throught the regulator or via another path? Are the R1 (D1) R4 low resistances so that a current through the lamp exists?
This is for an old-school type regulator, but not too old. The PCM he mentions is for a modern car. The previous era used "relays". This is a "solid state" design: NO moving parts. To understand this circuit, look at the zener diode on the base of TR2. Now look at the collector of TR2. If the voltage on the zener cathode gets too high, TR2 starts conducing more, robbing the TR1 base of current. This causes the TR1 collector current to drop, lessening the field current thus lowering the battery voltage. A balance is struck and this maintains itself at any speed.
sorry I didn't get back to you Richard I've been doing other projects however I like very much your analyzation of the circuit when I have a chance I'll go over it and try to find the schematic very impressed bye this this is the regulate a transistor nice analysis
About red wine it's usually there are three wires the very thick wires are the alternator also the starter motor and the other one is for the fuse panel concerning the black wires they are return wires for ground from the engine block and other ground return wires
I appreciate the comment the textbook actually is over 20 years old the one I use in school it's called automotive technology a systems approach thank you for your comment
These are Chevy trailblazers Chevy blazers suburbans mostly GM vehicles and usually it's the same for all other vehicles but they the pinout might be a little different thank you so much for your question Vietnam is a beautiful country
As long as a diode is forward biased you can make the cathode more negative or you can make the anode more positive either way the diable of conduct it depends on the load going on the alternator how much. Voltage output is
@@Joemaj939 The diode trio feeds the field winding inside of the rotor via the regulator. The 6 diodes recharge the battery and supply electricity to all loads while engine is running.
The current path through the diodes is always from positive to negatice (anode to cathode). This applies to all 6 diodes. 3 diodes supply current to the positive side of the battery. This current goes through the battery and exits through the battery's negative post. It then goes through the other 3 diodes and back to the stator winding that produced it. The current has to complete the circuit. It has to return to its source. That's why it's called a circuit.
That’s conventional theory never say always electron theory electron current flows against the arrow cathode thru the anode forward bias is.5or> to pass current. 2 different theories most use conventional our job is actually how much current is flowing in amp (work)CHEERS
You can try and Google what I use is actually a manual from the dealership which is actually over $200 but you can get cheaper ones from Google and put in alternator manual for your car
Good day Joe I have tried to get the book you are using ,but many editions came up, I am particularly interested in the one you are using, so if not a problem and you can give the name of the book, its author and edition I will be extremely grateful, on another note you have made reading automotive diagrams a walk in the park
If I have a 10SI GM alternator 100 amp and when you start the car it's putting out 14.5 volts and as soon as the electric fan kicks on the voltage drops to 12.9 volts ... Then if you turn the car off and then restart the car with no fan running or anything else drawing power but the voltage still stays at 12.9. what could be causing the voltage not to go back to 14.5??
Sounds like a regulator or it could be a computer that controls the alternator if you have a multimeter you can read your something called ripple on the AC volts scale make sure your belts are tight and the best way to do it is if you have a the force the alternator on
Put more accessories on and then rev up to 2,500 RPM and see if the alternator can take the loads voltage should be steady this is the first thing to do
is the output voltage different based on model of cars or different alternators ? as you said other video that we are going to get 14 V output from the alternator to the battery. what dose it mean if the alternator dose supply more than 14 v or less? thank you
Roughly they can vary from model to model but roughly they're in the area of 13.6 to 14.5 if it's colder it'll be even higher but eventually they'll come down and voltage
I don't understand if you said the computer replace the regulator. Because the regulator has diodes ; resistors ; transistors ; mosfet and capicitator ; and a coputer has the same components and both controlling the voltage ; ore does the computer control more voltage because it had more components with small components as well
The amount of components that I used whether in computer board or alternator board is it's relying on the function that you need if you need signals that are digital you will have more chips which are surface mount if you need a power supply you will still have a through hole components such as capacitors and transistors power transistors
The most important thing is the computer tells the alternator to control the field rotor current when you put a clamp meter on it which is why I recommended you will see the current change but the voltage will stay the same that's a sign at the computer is working and the regulator just keeping the voltage constant thank you so much for your question and being a viewer
How do i connect D+ on a -77 mopar? I thougt i should connect the old cable to the old extern voltage regulator. At first i thought i succed, the car charged 14,7 V at idle but when i tried to turn of the car it refused. i took off the connections to the batteri but that didnt help. But when i disconneted the cable to the old extern voltage regulator that now where connected to D+ the engine stopped. I tryed to run without the D+ connected, it worked but it dident charge So whats going on here? how to wire this correct?
There's a new wiring diagram for the new voltage regulator circuit if you go to Google and type in 77 Mopar wiring diagram for charging system you will see what I'm referring to
The name of the book is called automotive technology a systems approach the one that I use is actually a textbook from school many years ago you can Google it and you'll probably find it but it is a little advanced I find thank you for your question
I have seriuse headashe from all that staff. You see some cars work great on alternator back charge but baterry dies ither way discharges or over charges and I love plasma and amplifier ignition systems. Now be me is the problem I want dual system baterry and capacitor bank. Only problem for exampel if that capacitor dies expecialy on tractor alternators in Europ dead baterry,in other ocasion I used hv ceramic capacitors I ended up changeing me alternator starting charge rpm from 1k rpm some where up to 3-4k rpm so I need higher engine rpm to charge me baterry. So me question is how to make simpel system that does work variabel voltage regulator that is not effected from capacitors? And how to prevent baterry to interact with capacitors? Im lookeing at dual systems that do not share + or - conrctions. Basicaly for long time I want to coppy the magneto system with alternator and basicaly it does work if alternator starts to back charge for some reason if no diode is present in dashboard or arceing dual relays do know cause havoc with alternators. So sir how to prevent such unusual problem? Some alternators are even rotation dependent here in Europ if you for exampel use wrong turning direction alternator he also will not charge baterry. So does that book have any usefull information for dual baterry systems ? Its just idea but wuld normal current cutt out relay work for baterry and simply put inline capacitor banks as constant charge for other devices? Basicaly all I need the baterry for is for starter motor evry thing ells I need to be some thing ells for running different engine effects seperstly and programabel. So how is that achived if you want to prevent centrain effects to acure betwean 2 circuets who share common + or common - conection??? Thats what mostly confuse me. How ever I look at that voltage regulator it looks nearly identical to gm ignition modules or dual 5 pin relays so thats why me curiosety gets bether of me so I wonder if that alternator culd be made manuali variabel for centrain loads and aplications. So what me interests is what frequency range those regulators operate at and how to modifi cotectly resistors and capacitor values for centrain starting charge rpm ranges. Those seriuse questions schools do not teach properly in me opinion. So I hoppe you know some thing usefull that might explain those odd behaviors . In short Im lookeing for programabel alternators who can charge 2 systems seperatly and if posibel charge rpm starting charge ranges and if posibel to swap series/parrarel configuration switches for helpeing engine to start more easely. Suposedly there existed wacum tube baterry chargers and desulfation methodes baterrys be useing coils from high current dv motors but no one is realy specific hownthat works and why they took 1 full baterry and 1 dead baterry and used the dc motor coil polarity difference to transfare force current to dead baterry to desulfate it . Those S/R terminal starter selenoids confuse me as well no one realy talks about great things only basic crap . So me question is did some one actualy ever repaired that shity circuets because they fail and are anoying honestly . Me Delco 12si europ version alternator does lot more strange staff who are not mentioned so Im confused like hell about it . What I want simply programabel out put that alternator ignores baterry voltage and just push current constantly until the baterry is full. Because on plasma ignition ignition coil + and ground gound on those 2 ends from ceramic capacitors creating short basicaly. And me confusion is how to hell control that effect??? How to meshure some thing like voltage if baterry goes of scale and no current present???. So thats the problem here to understand . How to have multipel devices work seperatly or circuets in 1 and the same mashine ? For exampel magnetic brake,magneto,alternator ,series/parrarel conection switching,baterry/capacitor chargeing switching ,how to not get shocked if 2 frequencys are present in different potentials and other usefull information. Your video is great but wuld be even more bether if those mentioned problems wuld have some solution . Those mentioned effects destroy engines and cause rost in cars for years . So I cinde try to figure out how to get ride of it or bether how to control those effects. Those are valid questions who rarely some one asks but I have those problems . And aperantly profesors cant realy help me so hoppe you know some device that can properly modifi alternators and control them manuali with bether industri type parts .
@@Joeelectronicschematicsforauto Thanks Joe. I have a good problem today, the battery icon in the dashboard light up 10 second after engine starts. It only appears after 10s and it is repeatable. So I was thinking it is a ripple not filter out well by capacitor. I have change battery to new and voltage regulator. Charging voltage at battery pole is 14.2V and current up to 60A. Any recommendation what else to look. Thank you.
@@romylgequillana6288 if I understand correctly you are battery voltage is 14 volts but you are concerned about with a battery light blinking if that's the correct well obviously the first choice is always to make I'll check with the scanner but I assume that you don't have that instrument so the only thing you could do is if you think it's the alternator put your multimeter on a c v and measure the ripple it should be well low in the millivolts area
I'm looking at the text book now that you're referring to and you are correct 120° I don't know why I said 90° I was surely mistaken with this configuration of rectified diodes thank you for your correction and please feel free to correct with any mistakes and other videos thank you for being a viewer
It took me some time to find out. I think the response is simply to turn on the light from battery when the alternator is not running, and turn it off when alternator is running.
After the engine starts, the diode trio supplies current to the regulator and the regulator decides how much of this current to send to the rotor based on the input from the "sense" (S) line. The sense line is connected to battery voltage on one end and the regulator's "S" terminal on the other. If the regulator senses the battery voltage is to low, it sends more current to the rotor, thereby increasing the magnetice field. A bigger magnetice field in the rotor results in higher voltage and current being induced in the stator. The voltage from the rectifier (6 diodes) is used to recharge the battery and run all electrical systems in the car while the engine is running.
Good day Joe I have some problems locating the book on line as several editions came up. I would be grateful if you can furnish me with the author, edition and name of the book you use with your very educating sessions on RU-vid . Thank in advance Joe
@@Joeelectronicschematicsforauto yes, that's what I did, I search for information on Google and assemble it afterwards. but I wanted to know the name and publisher of this textbook so I could buy it if I found it on google. In one of your clips you showed the name and publisher of one of the textbooks (Automotive mechanics by Crouse and Anglin), I found it and managed to download it by exchanging it for another textbook of mine. That is why I am asking for the titles of each of your textbooks in order to find them and buy them. Thanks a lot for the answer. Knowledge is power 🙂
around 6:30 when you talk about the duty cycle of the field. you say that 50% duty cycle would result in producing 50% of the alternators rated output. I believe this is incorrect as you didnt account for the rpm of the alternator effecting the alternators maximum power output. max power cannot normally be obtained at low rpms.
This depends on the system in the model many makes and models have their own criteria GM's Asian cars and Asian cars the point that I went to the bank was you can use a clamp meter with a duty cycle to have an estimate of what's going on because I know most people don't want to use a scope to measure duty cycle
The other point being not only about RPM speed depends on the accessories that you have on in your car basic ideas with trying to keep the regulator constant while the current is changing
Over time a parasitic drained can be anything usually a module a relay that's stays on all the time overnight of course the lights and other accessories but an alternator can not charge the battery enough and then you have to live off the reserve capacity of that battery not really a drain from the alternator because even if the diodes in there are shorted you still will not have a short you will have ripple effect
I work on a lot of cars and specialize in diagnosing electrical problems. An alternator can drain your battery if one or more of the diodes short out. Current from the battery's positive terminal will go through the shorted diode to ground inside the alternator. After the engine has cooled (like first thing in the morning), if you touch the alternator it will be warm or you can use an infrared camera to see the heat.
You need to take a course on electronics,as your explanations are way out. For instance a capacitor doesnt stop AC from the rectifier diodes & 3 phase stator, has no 90 degree output to name a few mistakes.
They're usually on my channel Joe electronics schematics for Auto on the other one Automotive electronic schematics by Joseph unfortunately I did not have the time to list them I'm trying to recover from covid thank you for your suggestion
@@Joeelectronicschematicsforauto I hope good health for you We wait you in future to explaine regulator and how we can use it externally for other altarnator Also if there is possiple to upload this useful book Thanks
