Motorcycle Rectifier

[bioman]

Hi Guys

Thanks for your great forum, i restore classic Japanese motorcycles, i am from Johannesburg
South Africa (World cup country)
I need to build a rectifier for my old bike, i cant buy the part from the dealer as it is obsolete.

This is the info i have, the generator is a three phase AC generator, regulator and silicone rectifier.
Battery charging voltage is 15volts.
charging current, 2.0amps.
The AC generator has an output of 14.5volts and 13 amps.

The silicone rectifier is sealed and there is no access, i did test it as the manual specified, and found
no continuity on one of the pins, the plug has two pins at the top and three pins at the bottom.
If you van help i would gladly appreciate it.

If anyone is coming to the world cup, i would be happy to show you around.

Regards

 

[Boncuk]

Hi bioman,

this diode will most probably suit your needs.

It's a hyperfast recovery rectifier diode manufactered by NXP semiconductors. It can stand up to 20A at 600Vrms at low thermal resistance.

The diode's name is: BYC20-600, in a SOD59 (TO-220AC) package.

The alternator probably has a center tapped output, meaning to connect two diodes to the outer taps and use the center tap for common (ground).

Here is the datasheet.

Regards

Boncuk

 

[MrDEB]

Are you using an ohm meter to check the diode? If so then try switching the test leads around and/or use the diode feature on your DMM
sounds like a dumb suggestion but sometimes the simple common sense tasks are forgotten
Been there done that!.

 

[Hero999]

Are you sure the regulator isn't integrated into the rectifier?

That's often the case.

 

[crutschow]

Most, if not all, engine alternators are 3-phase, thus you need a 3-phase bridge rectifier (6 diodes). For example this should work. It needs to be mounted on some sort of heat sink.

A small nit but they are silicon rectifiers, not silicone.

 

[crutschow]

Are you sure the regulator isn't integrated into the rectifier?

That's often the case.

That's true for automobile applications, where the alternator is a self-contained unit. But most motorcycles have the alternator on the end of the crankshaft as part of the engine, with a remotely located rectifier assembly away from the direct heat of the engine.

 

[mel8030]

do you need the combined regulator-rectifier? is the alternator permanent magnet or field controlled?




**broken link removed**

 

[MikeMl]

Read this previous thread. It might give you some ideas.

 

[Hero999]

If it's just a three phase rectifier you're looking for, just use the following schematic.
**broken link removed**

There's no need to build it, you can buy modules.