Another stupid question

[sandhills]

I fired my little JD lawn mower up for the first time this spring and had to shut it off in the middle of mowing to help the kids unload 4H horses, long story but it got dark and the next day wife went out to finish mowing, no battery.  I pushed it to the garage and put the battery charger on it and instantly had smoke, not a good sign but at least it lead me to the problem, my stupid question is what is a rectifier?  This thing is about a 1/4" thick and 1'' x 1" with a positive and ground wire going to it and a screw going through the center into the front of the engine (Kawasaki).  To my surprise the local JD dealership was able to look it up but of course had to order it.  I found the company name and part number on it but had no luck looking for it on the net, best I could figure it is some sort of resistor?  Just curious I guess as to it's function and I'm sure most here probably already know so just thought I'd ask.

[Den Socling]

It's a diode. It allows current to flow in one direction only. Four diodes make a bridge which converts AC to DC voltage.

[pineywoods]

It's a bridge rectifier. The alternator under the flywheel makes alternating crurrent or ac. Not good for batteries. The rectifier converts to direct current needed to charge the battery. You can find replacements in the parts bins at the local radio shack, probably $2 or so. The legs are marked +  -  and ac.

[Den Socling]

A rectifier is a diode.  ;D

[sandhills]

Thanks guys I was just curious what it's purpose was, I can rebuild about anything but when it comes to electrical I'm one of those "you can't fix stupid" people, although I do make a really good ground  :D.  Piney, now that I've ordered it through JD I'm sure it will cost at least $40.00  :, I could read everything on it yet, the positive negative signs, Stanley, and even the part number, went to the web site but couldn't find the part.

[pineywoods]

Ttechnically, Dan is correct, but there's a bit more to it. There's 4 diodes in that black plastic block. The hole through the middle needs to have a small bolt or screw to hold it to something metal. That serves as a heat sink to keep the block cool. You really need a thin layer of heat conductive grease between the diode block and the heat sink when you go to install the new one. These things come in different current ratings, bigger is better. Radio shack will usually stock them up to a 50 amp rating, more than enough for your purposes..

[sandhills]

Thank you again Den and Piney, it did have a screw through it (it was tight), just couldn't figure out why it fired right up after sitting all winter, ran for 20 minutes, got shut off overnight then had a bad short.  Never fails just gotta ask you folks, learn something everyday and usually it's here, should've asked here before ordering it through JD!

[beenthere]

sandhills
Do you have the part number?
Or the model number of the mower?

Is it this dude shown at this site?  If so, that is about double your $40

http://www.greenpartstore.com/John-Deere-Ignition-Module--AM131398_p_4597.html

[Ianab]

It's probably a module like these

http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Dautomotive&field-keywords=john%20deere%20rectifier

$20  - $80 depending on the model.

As well as being a rectifier it probably has a regulator in there as well, so it not only converts the AC from the generator into DC, it also controls the charge going to the battery to stop it overcharging. So it will have a few more components in it than just a couple of diodes.

Now if you where stuck you could probably adapt a generic module, or even build something with electronic store parts. But if the genuine one is available for a sensible price, just get that.

Ian

[sandhills]

No beenthere that's not it but with my luck the price will be the same  :-\.  The mower is a SX95, the part says on one end (opposite the side of positive and negative signs) "Stanley DE45" and on the side is 7908Y2, I tried looking up both numbers, couldn't get a match for either.  I basically was just wondering what this part did.  Thanks for the link, if that price and Piney are both right Greenline can keep their part, I'll go to Radio Shack  ;D.

[Ianab]

http://www.dowdatractor.com/OemParts#%2fJohn_Deere%2fSX75_RIDING_MOWER_%289_H.P._ELECTRIC_START%29_-PC2106%2fRX95_%26_SX95_FLYWHEEL%2cSCREEN_AND_ENGINE_ELECTRICAL_PARTS%3a_ENGINE%2f21060006%2f2106B130A1202000022

The part is 30A or 30B depending on the serial # of the mower. I suspect it's a regulator AND rectifier module ???

If you replace it with just a rectifier you will probably fry the battery.

Ian

[sandhills]

Thanks Ianab it's 30a, I went to Stanleys web site and couldn't find anything but never thought of going to Deeres, what do you guys think fried it, or do they just go bad?  I've had the mower about 5 years and never had any electrical issues but the rest of it you can have, built VERY cheesy and VERY cheep!

[Ianab]

what do you guys think fried it

Heat and vibration are the enemies of electronics. Bolt something to the side of an engine, and you have both. So yeah, they can just die.

Ian

[VickiJo]

My husband and I work together like this: He does the work, I do the research. Came upon this forum by chance, needing a StanleyDE45 part, #7417y2, unable to find ANYWHERE, and Googled upon this forum. The additional info provided was helpful explanation for hubby who was thinking may be more of a problem than just replacing the diode. Haven't gotten part yet, but know what we need to do thanks to this forum!

[justallan1]

Welcome to the Forestry Forum, VickiJo.
You'll find bunches of folks here plenty willing to help any way they can.

[Magicman]

Welcome to the Forestry Forum, VickiJo.  Both you and your hubby will find a vast amount of information here and also some fine folks, plus one ole grumpy guy.  Grumpy, but we love him too.   ;)

[Chuck White]

Welcome to the Forestry Forum, VickiJo!

[Roxie]

Yes!  Welcome!   

[slider]

Ok magic man name that old grouch.If could be one of many.It might even be the boss.I can't wait spit it out.

[Magicman]

The Official FF "Grouchy Ole Man" is self named. 

[Hilltop366]

what do you guys think fried it, or do they just go bad?

Since it was the first time using the mower this season I am wondering if the battery may have been discharged enough to over load the regulator/rectifier.

It is best to fully charge the battery before first use and once or twice over the winter.

[sandhills]

Welcome to the forum VickiJo, I've yet to find a question asked here that more than a few members know a lot about and are more than willing to help with.  Stick around and get to know these folks!