Hi all,
OK, this is off the wall a bit, but by any chance has anyone done a converison from the stock 1/2 wave DC charging system to a full-wave system (or even to an AC system)? I'm looking for issues, ups, downs, recomendations for parts (rectifiers, etc.), and other comments.
1980 GS-450S
not sure what you mean by AC system, the stator windings put out like 75v ac before RR at about 2k rpm, or spose to, then need to be converted to DC for batt
The GS is fitted with an alternator that produces 3-phase AC. Tap the juice off from there and voila: instant AC! Output varies with speed, but is rated at 75V AC at 5000 RPM. I don't know if the rectifier is a full wave or half wave one, but three phases even at half-wave will give a pretty smooth rectified output.
You couldn't easily make the bike all AC (where are you gonna get 75V headlamp bulbs that fit?), for instance, the electronic ignition circuits need 12V DC: 75V AC would instantly fry them. You've also got the problem of starting without a battery, etc. etc.
Sounds like an interesting project though. If you could balance the load on the alternator, you could use one phase for DC and the other two for whatever.
Dana's got a 1980 GS. Didn't that have points? The old AC bikes used points and magneto.
If the 1980 headlight doesn't work with AC, you should be able to find an old one from a junkyard bike which does (but, really, do lightbulbs care whether they get AC or DC? Or even what voltage?
That said, I think the GS500 now has 6 diodes in the regulator/rectifier... which I think makes it a full-wave bridge rectifier (anyone? Starwalt?).
Quote from: Rema1000Dana's got a 1980 GS.....That said, I think the GS500 now has 6 diodes in the regulator/rectifier... which I think makes it a full-wave bridge rectifier (anyone? Starwalt?).
You rang?
Rema is correct in that the 89+ system does full wave rectification with the 3-phase bridge built into the RR (Regulator Rectifier). IF any filtering exists, I cannot find it in the schematics and it is probably internal to the RR and/or the Ignitor. The battery essentially buffers the RR output.
Here's a quote from my Suzuki manual (page 5-1):
"The AC current generated by the AC generator is rectified by the rectifier and is turned into DC current, then it charges the battery.
FUNCTION OF THE REGULATOR
While the engine r/min is low and the generated voltage of the AC generator is lower than the adjusted voltage of (sic) regulator, the regulator does not function. However, the generated current charges the battery directly at this time."
I am ignorant of the generator-electrical system on an 80 GS. Sorry! :dunno:
HI folks,
Thanks for the replies. To clarify ... there are some charging systems that are AC ... similar to the new BMW's, but I'm not exactly sure of the electronics involved. I know the AC to DC conversion happens much later in the circuitry as opposed to the "conventional" half-wave and full-wave RR systems GS.
Some of the older bikes had half-wave charging systems which dump half of the usable electricity to ground all the time. The full wave systems allow more juice to flow to the rectified circuit and then to the battery. That's where I need to be, but at this point, after staring at my schematics for a few days, I'm not sure what type I have. I need to make a few more calls.
My 1980 has fully transistorized ignitors ("KOKUSAN" black box) with inductive pickups (no points).
I put a scan of my schematics on my site if anyone is interested:
http://www.bndracing.com/schematics.htm (671k .jpg)
BTW ... my bike is all race with no street electrics. With the newly installed EFI system, my injectors start cutting out at about 4-5 k due to lack of juice, and the bike stalls out. This is because my stock charging system can't handle the icreased demand of the injectors & fuel pump at high revs.
(sorry for the long post)
HI folks,
Thanks for the replies. To clarify ... there are some charging systems that are AC ... similar to the new BMW's, but I'm not exactly sure of the electronics involved. I know the AC to DC conversion happens much later in the circuitry as opposed to the "conventional" half-wave and full-wave RR systems on the GS.
Some of the older bikes had half-wave charging systems which dump half of the usable electricity to ground all the time. The full wave systems allow more juice to flow to the rectified circuit and then to the battery. That's where I need to be, but at this point, after staring at my schematics for a few days, I'm not sure what type I have. I need to make a few more calls.
My 1980 has fully transistorized ignitors ("KOKUSAN" black box) with inductive pickups (no points).
I put a scan of my schematics on my site if anyone is interested:
http://www.bndracing.com/schematics.htm (671k .jpg)
BTW ... my bike is all race with no street electrics. With the newly installed EFI system, my injectors start cutting out at about 4-5 k due to lack of juice, and the bike stalls out. This is because my stock charging system can't handle the icreased demand of the injectors & fuel pump at high revs.
(sorry for the long post)
That is okay about the long post.
That is okay about the long post.
Looking at your schematic for the charging circuit...it is the same as the 89+ except for one wire of the gen windings goes through the "on" switch. You have a six diode 3-phase bridge like the 89+ units. You also have multiple gear position indicators like some of us have been discussing in another thread.
If your output is not fullwave...actually that is a bad description of this system; a more accurate description is rippled DC. If you are having issues with full output, something else is amiss.
Did you modify/change the wiring? If so, perhaps you left the switched gen winding lead out of the circuit? They show the SCR used for regulation on this schematic, something not done on the 89+ schematics.
At this point, I am not sure what your questions are. It looks like you have everything, schematic wise, to get a near DC output if all is working correctly.
Hi starwalt. Thanks for taking a look :) I'll go through the parts of the circuitry that you discussed and double check that all is intact.
I agree about the description and the names of the beasts. AC is a sin wave, and DC is just a pulse. Hmmm ... now I need to look further and edumacate myself a bit more :?
That wire from the generator you talked about (w/g to w/r) looks to me like it goes through the light switch not the ignition switch before heading back through the r/r ... :? I removed all the lighting stuff, so that will be the first place I look.
As to the wiring, I didn't modify anything, just hacked and slashed anything that I didn't need (lights, horn, key-switch, etc.). I kept all the key things stock ... but I may have omitted something, so I'll go over all again especially that third gen wire.
Quote from: starwalt.............................
Did you modify/change the wiring? If so, perhaps you left the switched gen winding lead out of the circuit? ...........................
Starwalt is correct. If you removed the light switch then you are running on only two of the three phases. At the connector for the light switch, connect the white/red wire to the white/green wire then you'll have all three.. :cheers:
Back in 1979 headlighs were required to be on when the bike is running. Most manufaturers replaced the switch so there was no light on/off but not Suzuki. They left the switch and put a set screw in so the rider could not switch it off. Everyone removed the set screws and had on/off lights. That would have been fine except Suzuki decided to connect the W/R to W/G in the headlight bucket and skip the switch. Disconnecting 1 wire in a three phase system disables 2/3 of the output (think about it) and that was required if the lights were off because the poor quality regulator in the R/R unit. The schematic you have is correct for 1978 and earlier GS's but not 79 and 80. On those the W/R and W/G are connected before the switch stock, but many people reconnected them back thru the switch so the lighting switch would work without burning out a $75 (at the time) R/R unit.
How do I know all this? I'm old.
Anyway, check the 6 rectifying diodes in the R/R with an ohm meter. I'll bet you have at least one bad. Also make sure you have 60v ac, unloaded, across the W/BL, W/G and Y wires out of the alternator at 5000rpm.
Pat
You guys rock!!! :thumb:
After untaping my harness (I'll never use electrical tape again), not only did I find the missing "snipped" pieces of the third phase coming off the generator (somehow the statement "Gee, I don't need lights or a switch anymore, so I guess I won't need this wire", comes to mind :oops: ), but I also found that one of the two existing generator leads had come loose inside the bullet connector shield. Turns out I was racing with only one-third of my charging capacity :o :o It's a wonder I was able to run at all.
Much thanks to starwalt and all the other good folks who helped out :cheers:
Did I mention you guys rock!!! :) :)
Off to the dyno.
Ok dana, ive read some of your web page and would love to know more about how you have your FI setup, what Diameter TB did you use? how much of a pain was it to put the megasquirt together? so and soforth.
would really love some pix of the setup. No im not going for speed records but many of us belive the GS will do far better with FI and a tonsilectomy
Quote from: Dana-GYou guys rock!!! :thumb:
After untaping my harness (I'll never use electrical tape again), not only did I find the missing "snipped" pieces...
I too find black tape a poor substitue. I just reworked the
entire harness of my project GS...and put it back with black tape. :roll: To at least update the old boy a bit, I replaced some short sections of tape with cool colored heat shrink.
To do this requires de-pinning some connectors and sliding the heat shrink over the pins and leads, putting it back together (in the right places) and then shrinking it down. There are several ways to mess this up so I don't recommend it unless you take good notes and have experience at handling the electricals. I had to make a couple of pin extractors for some of the connectors. Tedious work.
A merry welcome to routeinfo! We need more people here that know an ohm from a volt! :lol: