Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

jrtrebor wrote:
You shouldn't need a heatsink. If you use a screw or bolt to secure it. It should be fine. It will only need a heatsink if you are using it at or near its capacity.

The AC (~) terminals are pretty easy to connect. Typically you'll connect one to the charging coil output and the other to the engine block. If your coil has 2 outputs, connect one wire to each AC terminal. The open circuit voltage is going top be pretty high.
But it only really matters what the voltage is under load. Hook up a 12V automotive bulb to the (+) and (-) connections of the rectifier and see what happens. The bulb may burnout. If you connect your battery to the rectifier output + to +,  - to - the bulb won't blow, but the battery voltage should NEVER go over 14.5V. But let's keep in mind that these charging coils are used for this exact purpose. Also, if your charging coil has only one wire, do NOT connect the (-) output of the rectifier to the frame as a "ground".

A voltage regulator is a bit tougher to talk about. If you add a voltage regulator to this, it won't be like a typical voltage regulator in a car. The one in a car controls the alternator to keep output at about 13.5V. The one you would have to install would not be controlling the charging coil, but simply reducing its output voltage like a self adjusting resistor. It would have to dissipate heat. So at, for example, 17V from the rectifier, and 13V output, you need to drop 4V. At 6A, that means you have to dissipate 24W of power as heat. You can solder with 20W. So that regulator will get plenty hot.

Try the battery and bulb approach first.

JimmyM wrote:
Thanks for your response.  I do have two wires coming from the coil.  I understand what you're saying about the car regulator actually controlling the output of the alt.  Where as the coil on my engine simply
puts out what ever it puts out at any given RPM. My only real concern in this is not sending too much voltage to the battery.  I will be running lights when I need them.  But the rest of the time the battery will
only be used for starting the blower.  The 11hp Honda clone I was using had a 3A coil but it didn't seem to put out enough to keep the battery charged when I was running the light for an hour or two.
I'm sure I won't have that problem with this coil. I'm going to run another check to make sure that when I have the battery hooked into the system.  With the engine running full throttle that the voltage stays
some where between 12.5 and 14.5V.  I guess if I see that, that I'm good to go with buying and installing that rectifier on Ebay.  Any other things that I should know?

jrtrebor wrote:
Hang on. If the coil is designed to be connected directly to a battery, then it's not putting out AC, it's just unfiltered DC. Which is fine for light bulbs and for batteries. What do you think the alternator in your car puts out? Unfiltered DC. In fact, the battery IS the filter for the rest of the car's DC systems. Do you have a volt meter? If so, set it to DC and read the voltage off the coil wires. If you get a positive voltage one way and a negative voltage the other way. Skip the rectifier and just connect the battery and light. You're good to go.

Actually, you'll find a lot of articles that say pulsating DC is better than straight DC for charging lead/acid batteries because it reduces sulfation. OF course, the RMS voltage should still remain in the recommended 12.5 (low float) to 14.5V (absorption phase) range.

jrtrebor wrote:
It does look a little odd, but there could be a couple of reasons.
1. Combining the outputs of a standard "dual output" coil for greater current.
2. Each of the wires going into a single wire may be a diode output so the combined output is fully rectified DC instead of just the upper or lower halves of a half-wave rectified AC wave.

But, for sure, if the wires connected directly to the solenoid (starter solenoid) the you do NOT need a rectifier and the coil is designed to connect directly to a battery since the battery would be connected to the solenoid and ground.

Silly question. Was the meter set to DC or AC?

did you check to output from the coils before the rectifier to see if they were ac or dc?  If it is in fact DC you should not need the rectifier just connect the positive to the solinoid and the ground to a chassis ground and hook up the battery and then check the voltage again.

Carl

Gee, jrtrbor, I'm not sure what to make of this. 17.8V is way too high. You should be able to connect the BR+ output to either the Battery+ or the battery side of the solenoid. If you disconnected one of the coil wires from the BR~ connections, your meter would be showing the battery voltage if the leads were connected to the BR+ and BR- outputs. The coil shouldn't be putting any power through the rectifier at that point. 12.8V sounds right for a battery that was just subjected to 17.8V.

This is actually getting more confusing for me by the day, LOL.  I'm not sure that I know how to correctly check for AC voltage.  Or what kind of readings to expect to see.
I thought I did but the readings I tried to take this morning seemed to be all over the place.  And the readings between the two different coil wires are quite a bit different.  I was putting black probe to ground, red probe to coil wire.  Meter in VAC mode.  I'm just trying to be careful and not do something I shouldn't and burn something up, coils, rectifiers.

I hooked up the new Bridge Rectifier had a battery connected in the system.  Meter in VDC mode.
Black probe to ground red probe to solenoid + terminal and or battery + post.    At idle reading -14.2V 
Black probe to ground red probe to solenoid + terminal and or battery + post.     Full throttle reading - 17.2V

Removed Bridge Rectifier and hooked up borrowed Honda Rectifier, battery connected in the system. 
With a wire hooked to the B + terminal (left terminal) on the Rectifier.   At idle reading - 13.5V
With a wire hooked to the B + terminal on the Rectifier.    Full throttle reading - 16.8V

Second test with Honda Rectifier
Wire was moved to the IGN. terminal (center terminal) on the Rectifier.    At idle reading - 13.2V
Full throttle reading - with the wire hooked to the IGN. terminal on the Rectifier.    Full throttle reading - 13.1V
The other end of the wire that I'm talking about above is connected to the solenoid + terminal.  There are no wires coming from either rectifier going directly to the battery.  If the wire was connected
to the battery + post instead of solenoid + terminal could and or would that change the readings?

Can, and will the output voltage from the coils vary even when the engine RPM is constant?  I guess what I get a little confused about is whether both coils are independent of each other.
 Each putting out a certain amount of voltage at a given RPM.  How and or what happens when you combine them by connecting them to the Bridge rectifier or the Honda rectifier/ regulator.
I realize explaining this may be way more involved or over my head.  I get some of it, some of it I don't.  Was hoping to learn something out of this but I seem to be getting a little more confused
than I was.  I think I've learned that a Bridge Rectifier does nothing more than change or convert AC voltage to DC voltage.
Is 13 + volts enough to keep the battery charged when I'm running my small light.  I don't recall what the wattage is, but I know it's less than 50.  And the charging coil is supposed to be 10A.

The voltage will be the same if you measure at the B+ connection or the Solenoid+ connection. Will the voltage vary at a constant RPM? It can depending on what kind of regulator/rectifier is used. I have no idea what the IGN terminal does. Do you have a Honda part number for it? perhaps I could do a little searching for schematics using one and figure it out.