Heat sink and transistor location

[mallard8146]

Hi everyone It's me again with a dumb question but need to be sure. I need to know how close to the coil I can mount my heat sink and transistor that there won't be any interference magnetic or heat related problems also will gorilla glue work to connect maginets to rubber ? Going to change my name to Dumb Jim ha ha.


Thanks for any help Jim

[hobbyrobotik]

Hi Jim,

sorry if my English is not perfect, but all i have to tell you about heatsink is, that i never used and needes any heatsink in all my bedini builds until now.
My 7 Transistors keep cool while my machine is running with 4.5 Amps. So, no heatsink - no problem! Or does anyone in the forum have diffrent experience?
So i will be thankfull for suggestions....

regards

Dieter

[mallard8146]

Thanks Dieter, I hope this one runs cool also as I am building my first one and had no idea how hot they got. Sorry for the delay but our internet has been out, an explosion in Charlston WV a couple hundred miles away knocked out this area.
Thanks Jim

[Tom C]

help with the heat sinks and such

Hi everyone It's me again with a dumb question but need to be sure. I need to know how close to the coil I can mount my heat sink and transistor that there won't be any interference magnetic or heat related problems also will gorilla glue work to connect maginets to rubber ? Going to change my name to Dumb Jim ha ha.


Thanks for any help Jim

the trannys can be right next to the coil, it does not matter.

why do you want to glue magnets to rubber? are you not using a bike wheel? please do yourself and all of us a favor and build your SSG according to the instructions in the book, you will have no problems, it will fire up the very first time. other ways of building often produce large headaches for people.....

Just trying to be helpful

Tom C

[mallard8146]

My wheel is a 10 inch by 2 inch thick garden tiller wheel ,it has bearings. Used 8- 3/8 by 7/8 by 1 7/8 # 8 magnets, everything else is to plan.As this is all I had it's better than nothing. Just started it (first spin) charged a 12 volt lawn tractor battery and it worked perfectly.
Thanks Jim

[Tom C]

My wheel is a 10 inch by 2 inch thick garden tiller wheel ,it has bearings. Used 8- 3/8 by 7/8 by 1 7/8 # 8 magnets, everything else is to plan.As this is all I had it's better than nothing. Just started it (first spin) charged a 12 volt lawn tractor battery and it worked perfectly.
Thanks Jim

Jim,

an SG will charge batteries, that is not the point, the point is to not waste ANY energy charging your battery. a big heavy rotor will use a lot of current just to keep rotation. if your machine will charge a discharged battery of equal size to the primary with a bit left over, then your good, otherwise your burning current.

what is the current draw off the primary, and what is the wire size, length and no. of strands?

Tom C

[mallard8146]

Hi Tom, I was using a 3 amp 12 v dc power supply for the primary source and the amp meter read .24 and if you mean the wires connecting the battery it is just # 16 wire about 2 ft long. I used the power supply just as a test to see if it would run. If I have time today I want to use the lawn tractor battery to charge an ATV battery and I should get a better idea of the draw on the primary. I was short on wire and the coil only has 625 winds of #18 for the power and #20 for the trigger all other values are by the book. I.m a real beginner and this forum has helped me more than any other source I could find.
Thanks Jim

[Tom C]

thanks for the info Jim.

Tom C