Briggs engine has separate 2 alternators the same. (Called Dual type) Magnet wires wound in same slots. Opposite ends common grounds sealed to casting. Can I use both AC 5A AC 5A together parallel with diode for required half wave 14v DC as 7 amps load ? Can at same time use bridge rectifier on the AC two inputs for required DC out at 5 amps load ? Capability 14 amps DC full rectified at idle speed RPM. 10 amps for 7A out + 14 amps minus other amount used, for 5amps out to load? (Same time). No interference?

 

Your question is rather vague. I think some diagrams of what you want to do would help. Indicate voltages at key locations.

 

In general you can "OR" DC power sources together by using a blocking diode on each. The diodes prevent current from flowing from one supply to the other under any conditions, while giving the load access to both sources. Note that if one source is bridge rectified DC, the blocking function is already provided by the diodes in the bridge.

As noted, ask a better question to get a better answer.

 

A BIG CAUTION!! Beware of "commons" tied to "ground".
If any portion of one circuit is tied to "ground", then having any other portion of another circuit also connected to that common sets a trap for fault current paths. This means that you need to verify what is grounded befor connecting anything else to ground.
CERTAINLY it can be rather complicated.

 

In general you can "OR" DC power sources together by using a blocking diode on each. The diodes prevent current from flowing from one supply to the other under any conditions, while giving the load access to both sources. Note that if one source is bridge rectified DC, the blocking function is already provided by the diodes in the bridge.

As noted, ask a better question to get a better answer.

Wow! thanks! I will add blocking diodes on each line before adding Bridge to the half wave set up. Half wave output and full wave output same time. The dual (2) alternators have common ground in the back, underneath mounting of flywheel on Briggs lawn mower engine casting. There is a possible voltage regulator to add for 12v dc which also internally contains the bridge rectification. With that added, there is capability of about 14.5 amps dc . The half wave is max 8 amps unregulated, of 2 sides put together. Charts indicate that current varies with RPM.

 

Here is a warning! if one end of each of the windings is already tied to the common"ground", then a bridge rectifier intended to provide DC is simply NOT APPLICABLE!!
A bridge rectifier has two AC input connections that are for inputs NOT referenced to a common. ALSO, the two diodes at the top of the bridge already prevent any current from flowing into the positive terminal. So no isolation diode is required.

 

Here is a warning! if one end of each of the windings is already tied to the common"ground", then a bridge rectifier intended to provide DC is simply NOT APPLICABLE!!
A bridge rectifier has two AC input connections that are for inputs NOT referenced to a common. ALSO, the two diodes at the top of the bridge already prevent any current from flowing into the positive terminal. So no isolation diode is required.

I saw this application done years ago, with metered output of 14.5amps output from bridge rectification of 2 separate AC lines alternators. The 2 AC lines have common ground at opposite ends of wires. I just wanted to add another rectification of half wave DC output at a lower available 7 amps DC, by including them together with 2 added reverse blocking diodes, besides the output diode. (2) different load resistances and single phase type, as dual alternators is very common on riding lawnmower Briggs engines.

 

From that description it seems that there is no need for additional blocking diodes, since the rectifying diodes already prevent any reverse current. Now I see that a diode from the second winding may be able to collect additional current from the magnetic field collapsing. THAT can avoid a second diode drop thru another diode.
It does not seem like adding additional diodes will deliver any benefit, while it certainly WILL CAUSE A SECOND DIODE VOLTAGE DROP!!

 

This thread has some of the most confusing strings of words that I have ever come across. EVER!!
Besides that, just because something is demonstrated does not at all mean that it is not TOTALLY FAKED IN EVERY ASPECT!!!
What I get from the winding description is that there are two "alternator" windings around the same pole-piece in the magneto section within the flywheel. That is an interesting scheme to produce the 12 volts as the sum of two six volt windings. The fact that the two are tied to the common at opposite ends is an interesting way to produce 12 volts from two six volt windings. Really quite a slick trick! BUT tying one end to "ground" (common) puts quite a limit on the usefulness, as I see it. My caution still stands: when using a four-diode bridge circuit, the input source should not be tied to "ground"(common) at any point.

What the TS needs to do is draw us a circuit showing the two engine-alternator windings, indicating which end is grounded, start or finish. and what output voltages relative to "ground", or otgher points, are hoped for. Having a picture will be better for the understanding of how it is supposed to work.

 

This thread has some of the most confusing strings of words that I have ever come across. EVER!!
Besides that, just because something is demonstrated does not at all mean that it is not TOTALLY FAKED IN EVERY ASPECT!!!
What I get from the winding description is that there are two "alternator" windings around the same pole-piece in the magneto section within the flywheel. That is an interesting scheme to produce the 12 volts as the sum of two six volt windings. The fact that the two are tied to the common at opposite ends is an interesting way to produce 12 volts from two six volt windings. Really quite a slick trick! BUT tying one end to "ground" (common) puts quite a limit on the usefulness, as I see it. My caution still stands: when using a four-diode bridge circuit, the input source should not be tied to "ground"(common) at any point.

What the TS needs to do is draw us a circuit showing the two engine-alternator windings, indicating which end is grounded, start or finish. and what output voltages relative to "ground", or otgher points, are hoped for. Having a picture will be better for the understanding of how it is supposed to work.

This thread has some of the most confusing strings of words that I have ever come across. EVER!!
Besides that, just because something is demonstrated does not at all mean that it is not TOTALLY FAKED IN EVERY ASPECT!!!
What I get from the winding description is that there are two "alternator" windings around the same pole-piece in the magneto section within the flywheel. That is an interesting scheme to produce the 12 volts as the sum of two six volt windings. The fact that the two are tied to the common at opposite ends is an interesting way to produce 12 volts from two six volt windings. Really quite a slick trick! BUT tying one end to "ground" (common) puts quite a limit on the usefulness, as I see it. My caution still stands: when using a four-diode bridge circuit, the input source should not be tied to "ground"(common) at any point.

What the TS needs to do is draw us a circuit showing the two engine-alternator windings, indicating which end is grounded, start or finish. and what output voltages relative to "ground", or otgher points, are hoped for. Having a picture will be better for the understanding of how it is supposed to work.

In general, the Briggs brand engines on riding mowers have either single or dual alternators as common. The best ones are 2 black wires or 2 yellow wires as singles. They have the lowest ohms resistance for high amps. The common dual type has black and red opposite end wires attached to magnet wires wound on same plastic circle ring under flywheel of 12 magnets. Two ends are grounded together on casting top. Both are about 5amp AC. One line for running headlights on AC. The other has one diode for 14v DC , 4 amps, for charging battery under the seat. The RPM of flywheel has variable amps output. Half poles used on either side of ring. (not in same slots.) The wires on 4 poles each, 1/2 and 1/2 as 2 curves of 2 alternators. Way back in time, I saw meter reading of 14.5 amps DC output from the 2 AC outputs used together with bridge rectifier. (Not generally done on that type lawn mower.) The regular single winding alternator also uses bridge rectifier, but it is included in separate Briggs casing with voltage reducer regulator for 14V DC. Two things together. My desire was to add additional actual pulsing DC with single diode same time, and insure with additional blocking diodes in each line of dual alternator unit, tapped off. AC + AC for total available 8 amps pulsing DC of 2 lines together. This of course, would reduce the available output from the bridge section. Two separate loads. Pulsing DC is required for an electromagnet,- not AC or plain straight DC. If I use just the bridge section only, then I have to build a separate vibrating relay with open+ closing contacts to get the pulsing DC, with off time. THERE ARE THREE TYPES OF ELECTRIC CURRENTS!

Unrelated to the above, there is a U S Patent on increasing electrical energy by rewinding an old style motor/generator, with double winds in same slot on spinning rotor. The exterior electromagnet induces into wire 1 which reacts as rotation. The magnet also induces into wire 2 which induces rotation. Then, 2nd wire field induces into 1st winding. Resultant is excess torque of generator in the Alexander Patent. It just seems way easier to just use the plastic ring "Poles" of Briggs alternator since the main shaft is already turning, and exterior field is present, and not a forced field from an electromagnet. (No electrical input) The original rebuilt generator , long ago, was used to run air compressor motor , as mounted on car frame with air tank, and air hydraulic motors on wheels. Gauges of wires diameter was 1:3 as of the original gauge.

 

Having a picture will be better for the understanding of how it is supposed to work.

+1 I haven't been able make anything more than a general comment because i can't follow the details.