I want to roll my own generator

[loquin]

There is one reason that you might want to buy some diodes...

The alternator you build just isn't going to have a lot of voltage/power to waste. If you use standard, silicon diodes for the bridge rectifier, you're looking at losing apx. 1.4 V across two diodes in the bridge current path (the two that are dropping the voltage alternate during the AC cycle,) at any one time.

However, if you use Schotkey diodes in your bridge, they have a forward voltage drop that's about half that of standard diodes, so you'll end up with about .7 volts more at the load, and half the diode power loss.

Cars have power to burn (relatively) and the 60-70 watts they can lose in the diodes is very small in the scheme of things. But, if your alternator only puts out 40-50 watts total, 6 watts watts in the diodes is substantial - 12% of the total! Less than three (with schotkey diodes) would be about 6%...

 

[GearNut]

Thank you loquin! I have never heard of Schotkey diodes before. They sound like quite the ticket for these low power alternators.

 

[davidstipek]

Generator

Remember if you use a wheel driven Dynometer (Like our parents had an me when I was a kid. It is an AC power supply. You need to use a Rectifier of some sort to change to DC then you can charge battery. don't forget to install switch to disconnect battery when not being used.

I have been using this system to prove out wiring on chopper bike prior to engine install.

Note: You can also use flashing 12 volt LEDS for turn indicators. then no relay or flasher needed. I used red/blue in front with blue light lenses filtered out 95% of red. Same as back used red lenses and it filtered out 95% of the blue.

If you use 12V system it works. Also works with 6V system as minimum bightness difference.

Taillight we used white led mounted in center of lens and set 6V or 12V halogen flashlight bulb behind it for brake light.

you can also get dynamic headlight by using same Halogen flashlight bulbs in low and high beam (note use a diode to enable both to be used in High beam!) You can get bar mounted switches from Electric bike dealer or use bar mounted M/C switches, you can get on/off Hi/Low turn indicators and horn all in one

see photos:

David

 

[shell shock]

ok, so my build has been halted as my colleges machine shop is under reno this summer. bumer XP

SS