Rectifier

[Jim Stuart]

Hi, guys and gals. Just installed Radio Shack 276-1185 Rectifier, and the 276-1363 heat sink. Cranked it up in the garage and was getting 14.25 volts at about 3500 rpm. Getting 12.5 at about 2000 rpm. Think it is going to be good. My only question is if anyone else has done this, what is the temp. of the heat sink and module. Mine feels very hot to the touch. Also under the seat I am wondering about the ability of the heat sink to process the heat generated.

Thanks,

Jim

[305]

i put one on my CA77 a couple years ago even though i wasn't having any charging problems..so i can't really say if it made a big difference. the heat i have never paid any attention to , that's something i will have to check out

[Jim Stuart]

Thanks, If you have been running for some time with the new one, I guess it will be o.k. I was not having charging problems either, however this new rectifier seems to provide a little more voltage, and will hopefully keep the battery from going south during idle.

Thanks, again

Jim

[e3steve]

Guys, all rectifiers will get hot in the absence of charge regulation. The heat produced is a direct result of this. You probably won't be able to touch the heatsink for more than a few seconds, maybe less.

CHARGE RATE UPDATE:
I've now been riding my CB77 for a few weeks; here's a sitrep of the state of the charging after a couple of hours' stop/start excursion (all voltage measurement taken at the batt terminals; current flow measured at the fuse-link wire) -
Motor stopped : 12.65V
@ 2000rpm, light sw OFF : 12.70V / 0.8A
@ 4000rpm, : 13.00V / 1.0A
@ 2000rpm, light sw ON, parking light only : 12.85V / 1.8A
@ 4000rpm, : 13.10V / 2.5A
@ 2000rpm, headlight on (standard 35/35) : 12.50V / 0.1A
@ 4000rpm : 12.70V / 1.0A

As stated in previous posts, the battery is quite new (March 08) and has never been externally charged (aside form a jumpstart from my car when I flattened it tesing lights, winkers and pumping the oil round the motor using the starter after sitting for a couple of months).
When riding, I don't sit at traffic lights with my foot on the brake and I use the winkers sparingly. I always ride with the light switch ON but just on parking light -- a 5W halogen -- and flick the dimmer switch up (dipped beam) when navigating in traffic.

I've obtained from RS Components -- a mainly European seller -- both silicon-diode and Schottky-diode rectifiers, plus a neat little cylindrical heatsink. I'll be experimenting with both over the next couple of weekends and will post further tables.

Jim, make sure to check your battery electrolyte level an hour or so after a long ride (2hrs+, stop/start or continuous), as with 14V+ available and no regulator the battery will be receiving a fair whack. You need to wait for the battery to cool a bit (it will get warm) and allow any condensed electrolyte to return to the cells, so check a while after a ride or before the next.

Regards,

Steve

[Jim Stuart]

Thanks much esteve for the info on the rectifier, and the battery electrolite check. I just was a little worried about the heat and if it would ruin the rectifier. Much appreciated.

Jim