1970 1150 rectifier or "radio shack full wave"??

[j_martin]

Re: 1970 1150 rectifier or "radio shack full wave"??

As far as I recall the semiconductors are silicon and germanium. Silicon will yeild a .7v drop across the junction and germanium will drop .3v across the junction. In a full wave bridge rectifier you have 4 diodes and are always flowing thru 2 at a time so if the rectifier was silicon you would lose 1.4v at the output and .6 if it were germanium. Didn't know selenium could be used and therefore have no idea what the voltage drop accross that junction would be.

With about 70 volts overhead, it doesn't make a bit of differenct except for heat generated. Silicon generates more heat, but runs well at much higher temperatures than germanium, thus germanium is considered obsolete except in some very specialized applications.

Selenium ages poorly, is big, and was obsoleted by silicon 40 years ago.

hope it helps
John

 

[jimg984]

Re: 1970 1150 rectifier or "radio shack full wave"??

John is this rectifier from radio shack and what model?
hard to see in the pic all the wires you are talking about
if you could do a sketch and post it would help me
i want to do this,,, but do it right and not burn my stator out

thanks for your help
jimg984 "hilly billy in NC"

 

[j_martin]

Re: 1970 1150 rectifier or "radio shack full wave"??

Shoot. I just looked and the radio shack one is only 50 V PIV. You need at least 200 V.

I get mine at a surplus place. I'll go find one for you and come back

John

 

[j_martin]

Re: 1970 1150 rectifier or "radio shack full wave"??

This one will work just fine. $2.50 each


http://www.allelectronics.com/cgi-bin/item/FWB-352/search/35_A_200_PIV_BRIDGE_RECTIFIER_.html

hope it helps
John

 

[j_martin]

Re: 1970 1150 rectifier or "radio shack full wave"??

Diagram and picture

Backing plate is of 1/8 inch aluminum. Center hole is countersunk from the back, and a flat head machine screw is used to bolt it down. That gives maximum contact between the rectifier and the backing plate, and between the backing plate and the switchbox mounting plate.

hope it helps
John

 

[j_martin]

Re: 1970 1150 rectifier or "radio shack full wave"??

Here's another one 1200 V, would take a bolt of lightning to kill it.

http://www.mouser.com/search/ProductDetail.aspx?R=36MB120Avirtualkey64010000virtualkey640-36MB120A

 

[Diverted Income]

Re: 1970 1150 rectifier or "radio shack full wave"??

With about 70 volts overhead, it doesn't make a bit of differenct except for heat generated. Silicon generates more heat, but runs well at much higher temperatures than germanium, thus germanium is considered obsolete except in some very specialized applications.

Selenium ages poorly, is big, and was obsoleted by silicon 40 years ago.

hope it helps
John

Learn something everyday. I knew the Vp-p was high as it is unregulated and running wild. Thanks for the info.
Craig

 

[Jimmy70]

Re: 1970 1150 rectifier or "radio shack full wave"??

I installed one of these rectifiers on my 40hp Mercury and so far it is working fine. Bought two of them for $7. Easy to install. I removed the old one that was shot, drilled a hole in the plate between the other two old holes, added some heat sink compound, silver stuff I had for my computer heat sink, and mounted it quick, installed some new lugs on the wires and was off and running.
Jimmy

 

[kellyisu]

rectifier or "radio shack full wave"??

rectifier or "radio shack full wave"??

I am on a college budget and am just replacing my switchbox and stator$$$. I would like to replace the the rectfier as well but sure would like to save some money right now and try this radio shack rectifier. No ohm reding off one of the prongs, so I should replace it even though it is still getting the job done.

Motor- 1979 Mercury 40hp 2-cyl

The three prong rectifier with the red wire(from starter selonoid) to the + and the 2 yellow stator wires to the other two is what I currently have.

How would I rig this up? I have read the other posts, but I need some more reassuance in doing this on my motor.

Tell me if I have this right:
I need at least a 200V rectifier, correct?
I mount this rect. where the old one was. I will have to change the the ends of my wiring to female connectors. Red wire to +, each one of the 2 yellow stator wires to a seperate AC, then I can run black (lets say) wire of the proper gauge from the neg(-) to a ground somewhere on the motor.

Thanks!!!!


WELL I JUSTFOUND THIS
Here are the steps:1) remove Merc regulator (unbolt wires & housing)2) pry off metal baseplate & grind smooth.3) drill a countersunk hole in the center of the plate so a tapered head bolt will sit flush. 4) put thermal grease (from computer store) between the regulator and the plate5) bolt on the Radio Shack regulator ($5) & threadlock so it doesn't vibrate loose. 6) replace Merc wire terminations with spade type or solder directly to regulator. Use heat shrink tubing to protect connections.7) solder negative terminal to motor housing ground since Radio Shack has 4 leads & Merc internally connects 2 together.8) put thermal grease on back of base plate & bolt on using original bolts & holes.Nice to have a fully charged battery without lugging the thing around to charge it!

 

[Profittakr]

Re: 1970 1150 rectifier or "radio shack full wave"??

Will this work on an '88 70hp Yamaha as well? I think my battery is charging ok but the tach does not work and I know it is not the tach as a brand new tach had the same issues. I functions and registers but not correctly. Yes, the poles are set correctly too (6 pole). Seems to read about 1/2 what it should at WOT and probably double at idle.

I tested the rectifier per the manual and NOTHING seemed right. Battery does charge though and tach gets some sort of reading but apparantly not an accurate one.
Just wondering if I can try this without killing anything else. Yamaha rectifiers are nearly $75; aftermarket is over $50.

 

[j_martin]

Re: 1970 1150 rectifier or "radio shack full wave"??

Will this work on an '88 70hp Yamaha as well? I think my battery is charging ok but the tach does not work and I know it is not the tach as a brand new tach had the same issues. I functions and registers but not correctly. Yes, the poles are set correctly too (6 pole). Seems to read about 1/2 what it should at WOT and probably double at idle.

I tested the rectifier per the manual and NOTHING seemed right. Battery does charge though and tach gets some sort of reading but apparantly not an accurate one.
Just wondering if I can try this without killing anything else. Yamaha rectifiers are nearly $75; aftermarket is over $50.

Heck, how would we know, we're murkery guys.

Go ask the generic question on the yamaha thread.

 

[arsenalpsu]

Re: 1970 1150 rectifier or "radio shack full wave"??

I have a 1984 115hp I-6 which needs a new rectifier. Is the radio shack one mentioned above good or should i go with the following:

http://www.allelectronics.com/index...query=35_A_200_PIV_BRIDGE_RECTIFIER&x=27&y=10

thanks.

 

[j_martin]

Re: 1970 1150 rectifier or "radio shack full wave"??

I have a 1984 115hp I-6 which needs a new rectifier. Is the radio shack one mentioned above good or should i go with the following:

http://www.allelectronics.com/index...query=35_A_200_PIV_BRIDGE_RECTIFIER&x=27&y=10

thanks.

That one's better than the rat shack one. I'd use it.

There's probably 2000 similar parts that will work. Higher reverse voltage rating is always good.

John

 

[Faztbullet]

Re: 1970 1150 rectifier or "radio shack full wave"??

Why not install the Serria 18-5707? Its a direct replacement, no need to modify wiring,make plates,change terminals and has a warranty for the life of the vessel on which installed and can be purchased off iBoats... pretty good I think but just my $.02

 

[arsenalpsu]

Re: 1970 1150 rectifier or "radio shack full wave"??

Why not install the Serria 18-5707? Its a direct replacement, no need to modify wiring,make plates,change terminals and has a warranty for the life of the vessel on which installed and can be purchased off iBoats... pretty good I think but just my $.02

Well it's about 20 bucks cheaper to go with the one i posted above. From what i've read here the direct replacements are junk and just cover what you need. Any thoughts??