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# Help selecting a 1A BJT for 200KHz switching?

#### Lightium

##### Active Member
I need help selecting a BJT that's rated for around 1 amp collector current and can handle 200KHz switching. VCE should be greater then 20V.

I ask because as I increase the frequency on my oscillator section the driver sections output current reduces.

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Thanks heavens that in a simulation, inductors never saturate, resistors don’t burn and the BJT transistor don’t go into secondary breakdown.

I'm talking about your targets. " 24KV (on target) and 12mA (20mA is target) ".
In order to get at least 20ma at 24kv, your load has to be 1.2Meg or less.
Air gaps have essentially infinite resistance until they break down. Then they're on the order of milliohms.

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I'm talking about your targets. " 24KV (on target) and 12mA (20mA is target) ".
In order to get at least 20ma at 24kv, your load has to be 1.2Meg or less.
Air gaps have essentially infinite resistance until they break down. Then they're on the order of milliohms.
No, we're missing something, because I have a circuit like this that run's at 154Hz and outputs 34KV at 17mA with a nice waveform on L1 that starts from zero amps and reaches 3.6A.

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No, we're missing something, because I have a circuit like this that run's at 154Hz and outputs 34KV at 17mA with a nice waveform on L1 that starts from zero amps and reaches 3.6A.
34kv/2Meg=17mA. No discrepancy there.

I started over from scratch and got as far as 6KHz with the output giving 24KV 12mA pulses.

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• phoenix-hf-6KHz.asc
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Don't be offended. I just don't know what your level of knowledge is.
Do you know Ohm's Law?: V=I*R ?
Iout= V(HV)/(R14+R15+R(L2)+R9).
11.928mA=24kV/2.012 Megohms

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