another electric quizz: rectifier/regulator ?

Hi, after the alternator debate , the normal following should be : what to use as rectifier /regulator, long time ago we had no choice just Zener and the three discs rectifier and it work well, but now we can fit a cheap magic box which does both job for 25£, or a more expansive same look Podtronic, or in the same price league a Pazon, or a Boyer power box..............do they work better , last longer , or protect better those cherished electronic units and /or Li-ION batteries?

marinatlas said:

Hi, after the alternator debate , the normal following should be : what to use as rectifier /regulator, long time ago we had no choice just Zener and the three discs rectifier and it work well, but now we can fit a cheap magic box which does both job for 25£, or a more expansive same look Podtronic, or in the same price league a Pazon, or a Boyer power box..............do they work better , last longer , or protect better those cherished electronic units and /or Li-ION batteries?

Click to expand...

My rectifier (original) actually broke a diode. I pulled it out and went and picked up a rectifier from Radio Shack for about $5. I actually bought 2 and keep one on the bike as a spare. The connectors were a direct match and I still have the zener installed. The only thing I did was make a finned heat sink and mounted it either in the same hole or one near by where the original rectifier was mounted. It has been on the bike since last summer without issue. If and when the zener goes, I will probably go with something like a Podtronics.
http://www.radioshack.com/product/index ... Id=2062584

I replaced the zener and other related 40 year old stuff for a Boyer Power Box 15 years ago.

I think it was about $135 back then, and I am very glad I did, works perfectly as expected, converts the alternator current to battery charging and eliminates the excess current/heat dump.

I had a 180W Lucas 2 phase alternator/rectifier/zeners and recently changed to a podtronics because the Alton Estart alternator was single phase. There is no difference whatsoever in performance as far as charging voltage or anything else between the two. I wouldn't change to a Podtronics just to change; I would change if the oem stuff broke but otherwise I don't see any reason for it.

mike996 said:

I had a 180W Lucas 2 phase alternator/rectifier/zeners and recently changed to a podtronics because the Alton Estart alternator was single phase. There is no difference whatsoever in performance as far as charging voltage or anything else between the two. I wouldn't change to a Podtronics just to change; I would change if the oem stuff broke but otherwise I don't see any reason for it.

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No such thing as a 2 phase. It would either be single phase or 3 phase. All the originals and the Alton are single phase. Jim

drones76 said:

marinatlas said:

Hi, after the alternator debate , the normal following should be : what to use as rectifier /regulator, long time ago we had no choice just Zener and the three discs rectifier and it work well, but now we can fit a cheap magic box which does both job for 25£, or a more expansive same look Podtronic, or in the same price league a Pazon, or a Boyer power box..............do they work better , last longer , or protect better those cherished electronic units and /or Li-ION batteries?

Click to expand...

My rectifier (original) actually broke a diode. I pulled it out and went and picked up a rectifier from Radio Shack for about $5. I actually bought 2 and keep one on the bike as a spare. The connectors were a direct match and I still have the zener installed. The only thing I did was make a finned heat sink and mounted it either in the same hole or one near by where the original rectifier was mounted. It has been on the bike since last summer without issue. If and when the zener goes, I will probably go with something like a Podtronics.
http://www.radioshack.com/product/index ... Id=2062584

Click to expand...

Found one today at my local Radio Shack. $4.29. Good buy. I now have a spare also.

Just a followup. I put a multicolor voltage indicator light on my bike a while back ( I removed the Assimilator when rebuilding it). Green is charging in the correct range, orange is low and red is below 12volts or so. Last night a short ride around town the red stayed on. It will occasionally come on at a long light and then when the revs get back up it goes green. It did not leave the red range this time out. Hopped on the highway to see if it would charge back up. No dice. When I got home, I left it running and got the meter out. 9.75 volts across the battery. I shut it down and tested with it off. 12.7 volts. It seems my $5 rectifier bit the dust. It has been on there over a year. I took the spare out and plugged it in. Ran a few blocks and back to green. I still plan to upgrade a combo unit but for now a few bucks a year ain't so bad, as long as I carry a spare.

drones76 said:

Just a followup. I put a multicolor voltage indicator light on my bike a while back ( I removed the Assimilator when rebuilding it). Green is charging in the correct range, orange is low and red is below 12volts or so. Last night a short ride around town the red stayed on. It will occasionally come on at a long light and then when the revs get back up it goes green. It did not leave the red range this time out. Hopped on the highway to see if it would charge back up. No dice. When I got home, I left it running and got the meter out. 9.75 volts across the battery. I shut it down and tested with it off. 12.7 volts. It seems my $5 rectifier bit the dust. It has been on there over a year. I took the spare out and plugged it in. Ran a few blocks and back to green. I still plan to upgrade a combo unit but for now a few bucks a year ain't so bad, as long as I carry a spare.

Click to expand...

Nothing wrong with the Radio Shack rectifier but you would want to get a higher voltage rating. At least 100 or 150 volts. A 50 volt regulator is easily damaged by voltage spikes on the line. Usually caused by switching things on and off. Jim

drones76 said:

Just a followup. I put a multicolor voltage indicator light on my bike a while back ( I removed the Assimilator when rebuilding it). Green is charging in the correct range, orange is low and red is below 12volts or so. Last night a short ride around town the red stayed on. It will occasionally come on at a long light and then when the revs get back up it goes green. It did not leave the red range this time out. Hopped on the highway to see if it would charge back up. No dice. When I got home, I left it running and got the meter out. 9.75 volts across the battery. I shut it down and tested with it off. 12.7 volts. It seems my $5 rectifier bit the dust. It has been on there over a year. I took the spare out and plugged it in. Ran a few blocks and back to green. I still plan to upgrade a combo unit but for now a few bucks a year ain't so bad, as long as I carry a spare.

Click to expand...

I've been using a Signal Dynamics LED voltage indicator for a few years now and it recently let me know the zener diode had failed by flashing green for overvoltage (the headlight was off) and awhile back let a friend with a Triumph T140 know his charging system had failed and he was able to limp home before the battery died. I happened to have a spare zener that came w/ my bike and that fixed it, but if I hadn't I would have installed a Podtronics unit as the cost is about the same as a new zener, about $50.

I'm still working on my original electrics but if anything goes wrong, it's most likely the Podtrinics.

When I had to change the stator on my 72 750 I replaced it with a 3 phases alternator (because we are required by law to have the lights on at any time which require high output even at low rpm) so I put a 3 phases Boyer black box ( rectifier+ regulator). In order not to change the wires I leave the Zener on the Z plate.

I know the Zener is now useless but do you think it can hurt ? Should I remove it and isolate the wire or can I leave it as it is ?

JRD said:

...so I put a 3 phases Boyer black box ( rectifier+ regulator). In order not to change the wires I leave the Zener on the Z plate.

I know the Zener is now useless but do you think it can hurt ? Should I remove it and isolate the wire or can I leave it as it is ?

Click to expand...

If the Boyer charging voltage is higher than what the Zeners cascade at (quite possible), you'd be in a situation whereas the excess voltage would be shunting to ground through the zener, and merely be going out as heat. I'd recommend disconnecting and isolating the wires to the zener, and let the Boyer take care of the regulation.

Boyer powerbox works well and has the assimilator built in, and I'll keep on using them.
But no matter how good they are, the excess current still has to be dumped somewhere - the alternator output isn't controlled - it's just diverted!

Heatsink still required :roll:

"you'd be in a situation whereas the excess voltage would be shunting to ground through the zener, and merely be going out as heat."


I understand how the Zeners work and have often heard folks state that the excess voltage goes out as heat as if that's a bad thing. But who cares? What difference does it make what the system does with the excess, whether it's a "smart" system that simply doesn't produce "excess" voltage or one that dumps it to ground? The end result to the bike's charging system/battery is the same.

As I posted in a previous message, my bike has the 3 phase Lucas alternator (not a 2 phase as I typo-ed ! ) The output of the Lucas/zeners and the Alton alternator/podtronics was exactly the same at all RPM. So although the Podtronics could be called more efficient, I guess, since it doesn't dump any excess V to ground, who cares what the system does with the excess? It's not like we are leaving the house with the TV on and paying for the use of electricity for nothing.

IOW, I don't see any operational disadvantage to the oem system and would see no reason to replace it unless it fails.

It may not show up on your light bill but it does show up on your gas bill. Admittedly tiny. Jim

"It may not show up on your light bill but it does show up on your gas bill. "

Hmmm, then some sort of KERS is what we need! It would be great for those occasional brushes with a Hayabusa!

I have a large alternator on my FI bike. 38 amp. It takes a lot of power to turn it when it is working hard. When I switch on the three headlights it will slow the idle by a couple hundred RPM. If I shunt the output it will stop the motor at idle. It is necessary to use a regulator that unloads the alternator when the maximum voltage is reached as it would require a good 4 or 5 horsepower to turn it at speed with the output shunted. That would require a very large sink to deal with the heat.

It isn't a big deal with a small alternator such as the one on a Norton but it still pulls close to 1 horse from the motor at high rpm when it is shunted. Jim

mike996 said:

...and have often heard folks state that the excess voltage goes out as heat as if that's a bad thing. But who cares?
IOW, I don't see any operational disadvantage to the oem system and would see no reason to replace it unless it fails.

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I agree; who cares? But here's something to consider. Assuming the Boyer was peaking at, say 14.5 volts, whereas the the zeners might be more like 14.2 volts (purely hypothetical in both cases), then you'd have the zeners dropping the voltage to something less than ideal. Ideal, only in the sense that 14.5 would more reliably charge the batery, light the headlamp, and (a big one for me), run the flashers at a realistic rate!
If, on the other hand, the zeners were set to cascade at a value above what the Boyer was producing, then no harm done with leaving them connected.
And, I also agree; if it ain't broke, don't fix it!