Beta Matching

[lost_in_samoa]

Hello,

I think I understand the purpose of Beta matching components. The end result is to get all of the power windings on all of the coils firing at exactly the same time.

It seems that there are different methods of doing this. Some build circuits to test the components in question. Some buy Hfe testers. Some use standard pn junction measurements to match components.

Question .....

Is there another way to accomplish this goal?

For some of us just getting components is a major undertaking. Getting a large enough stock of matched components is VERY difficult.

For the transistors,

I know its possible to trigger an oscope off of the trigger coil. It follows that using that timing you can now measure the firing delay at the collector.

Could a compensating delay be put on the base to retard transistor firing?

Thank you for your time.

[Tom C]

Hello,

I think I understand the purpose of Beta matching components. The end result is to get all of the power windings on all of the coils firing at exactly the same time.

It seems that there are different methods of doing this. Some build circuits to test the components in question. Some buy Hfe testers. Some use standard pn junction measurements to match components.

Question .....

Is there another way to accomplish this goal?

For some of us just getting components is a major undertaking. Getting a large enough stock of matched components is VERY difficult.

For the transistors,

I know its possible to trigger an oscope off of the trigger coil. It follows that using that timing you can now measure the firing delay at the collector.

Could a compensating delay be put on the base to retard transistor firing?

Thank you for your time.

the transistors will fire at the same time, it is not a matter of when but how much the base opens, as it is voltage driven, you want all the branch currents the same to the base, then all of the bases open the same amount. so the power coil output is balanced between all strands. the spike is then not unbalanced. imagine 7 selenoids all opening different amounts letting different volumes of water thru, not good. if they all open the same, then you can get maximum output from each strand.

Tom C

[lost_in_samoa]

thank you. Let me noodle on that a bit.