2n3055 transistor question

[TheOne]

The losses through a 2N3055 at that kind of frequency are horrendous.  Change transistors to something more appropriate and it will be a SUPER slayer.

Please note my video test from my previous post was a 10% duty cycle. Also youtube converted my video in bad quality I dont know why...


I have 2 others transistors rate at 7mhz. BU208A, well rated higher then 2n3055, but for my initial test i will stay with 2N3055 because I will start with lower frequency at first.

[Void]

I don't know what is the max frequency a magnetite core can handle, I will need to experiment.

The frequency range that any core can be used at depends on the specific type of core material you are using.
Iron and iron powder and silicon steel are typically only useful at very low frequencies. Different ferrite compostions
are suitable for differrent frequency ranges depending on the specific ferrite composition. Usually manufacturers
of different types of core materials provide details in data sheets on what frequency range their different core compositions are
suitable for. Also, you should be aware that some LEDs do not work as good at higher frequencies as other types of LEDs.
I have two sets of white LEDS from different sources that look pretty much the same on the outside, but only
one of the sets of LEDs works well at frequencies in the high kHz or MHz range. The other LED type only lights
at low frequencies. You should test your LEDS with a signal generator and series voltage limiting resistor over a
range of frequencies to see what frequency ranges the LEDs can light at.

All the best...

[TheOne]

ok good to know!


I made another test, changing the duty cycle to 20% and I can go to 1.8mhz (led on) but after then it fail
at 30% duty cycle the led light up to 3.1mhz and stop after that


but I know the frequency is probably not good enough to do what I want to do but I can see what the transistor is able to do

[MarkE]

Please note my video test from my previous post was a 10% duty cycle. Also youtube converted my video in bad quality I dont know why...


I have 2 others transistors rate at 7mhz. BU208A, well rated higher then 2n3055, but for my initial test i will stay with 2N3055 because I will start with lower frequency at first.

A GBW product of 7MHz does not mean that the transistor works at 7MHz.  It means that at 7MHz you have to pump as much power in as you get out.

[TinselKoala]

The losses through a 2N3055 at that kind of frequency are horrendous.  Change transistors to something more appropriate and it will be a SUPER slayer.

Yes, you are right, there is probably more power being dissipated in the transistor than is being put to useful use. It works quite well with a TIP35C, too, and perhaps wastes a bit less power.