Sharing Components (resistors, diode)

[lcstier]

First let me thank all who go to the trouble to answer all the dumb questions.
I am new to the Bedini Motor build, I have a small trifilar working and
have purchased the Beginners and Intermediate books.
My motor is built with a hard drive bearing using a CD to make the rotor
with 8 North facing magnets
The transistors I'm using are NTE196, I have also purchased TIP31's but
have not run these.

My question is: Is it OK to share components like base resistors and collector diodes?

I ask this question because I will be matching components in the near future and
got to thinking, Why not use just one base resistor to trigger both transistors this
would eliminate one of the components and matching problems. Today I did just that and it has been running fine all day.
Thanks again for any help you my give me.
Linnie

[Tom C]

First let me thank all who go to the trouble to answer all the dumb questions.
I am new to the Bedini Motor build, I have a small trifilar working and
have purchased the Beginners and Intermediate books.
My motor is built with a hard drive bearing using a CD to make the rotor
with 8 North facing magnets
The transistors I'm using are NTE196, I have also purchased TIP31's but
have not run these.

My question is: Is it OK to share components like base resistors and collector diodes?

I ask this question because I will be matching components in the near future and
got to thinking, Why not use just one base resistor to trigger both transistors this
would eliminate one of the components and matching problems. Today I did just that and it has been running fine all day.
Thanks again for any help you my give me.
Linnie

no its not, please use individual resistors, each transistor base then gets the same current, otherwise the base that is weakest will open up more than the others, the resistor isolates the base in the trigger circuit.

if you build like he designed it you will get the results he states, otherwise do not expect much, a running circuit is different that a tune circuit.

build a bike wheel..... you will be happy

Tom C

[lcstier]

Thanks Tom for the insight
Linnie

[beny82]

@ lcstier, each and every transistor has a specified rating. When you use just a single transistor, all the load will be put on this one transistor and it will most likely malfunction. Even if you think the current is collectively less than what's specified in the datasheet, I'd advise you not doing this because at the maximum limits, the transistor will get hot. Coming towards the general practice, it is very common to use a transistor with double the limitations according to the datasheet. That means if you're current on an average through a path is 1A, the transistor rating that you should use should be around 2A, just to be safe.