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1. niconiconi (niconiconi@cybre.space)'s status on Tuesday, 25-Jan-2022 05:06:13 UTC niconiconi

   > testing the pulse-energy endurance of electronic components such as resistors and transient voltage suppressors.

   I think I don't really need to design this HV pulser. Just realized the X Chapter in The Art of Electronics already has exactly what I was looking for. https://x.artofelectronics.net/wp-content/uploads/2019/11/3xp15_HV_pulsers.pdf #electronics

   • niconiconi (niconiconi@cybre.space)'s status on Tuesday, 25-Jan-2022 05:06:09 UTC niconiconi

     in reply to

     Received two 100 volts electric shocks while testing this, Electroboom moment. Note to self: Do *not* touch the output capacitor bank without discharging... Even after the output went to zero, it only means the voltage is too low for the switch to turn on, but the capacitors themselves are still at 100 volts! #electronics #usb

     Santa Claes 🇸🇪🇭🇰🎅 likes this.
   • niconiconi (niconiconi@cybre.space)'s status on Tuesday, 25-Jan-2022 05:06:10 UTC niconiconi

     in reply to

     More USB killer waveforms captured, unlike the last test (see thread) with an open circuit, this time it's connected to a 50 Ω load.

     It keeps pulsing once it's connected, peak voltage is typically 140 V, but can be as high as 200 V. Pulse width is about 100 μs to 250 μs. Repetition rate is about 27 pulses per second. The pulse characteristics are poorly controlled, I suspect it's triggered by the arcing inside a gas discharge tube, typically used for surge protection (the irony...).

     Like the last unit, this (identical) one also damages itself after continuously pulsing for a minute or so. It can no longer generate continuous pulses. #electronics #usb

   • niconiconi (niconiconi@cybre.space)'s status on Tuesday, 25-Jan-2022 05:06:11 UTC niconiconi

     in reply to

     The original plan - let the USB Killer send its energy straight into a 50 Ω oscilloscope input through a big RF attenuator - is flawed. No reasonable RF attenuator can sustain such an energetic pulse.

     New plan: Probe the voltage via a 450 Ω or 4950 Ω series resistor, this forms a 10x or 100x transmission line probe when combined with a 50 Ω input with good signal integrity. Also, the load should be installed on the PCB, using the instrumentation itself as a test load is a bad idea... #electronics #usb

   • niconiconi (niconiconi@cybre.space)'s status on Tuesday, 25-Jan-2022 05:06:11 UTC niconiconi

     in reply to

     Success. The 100x transmission line probe (5.1 kΩ in series with 50 Ω oscilloscope input) is working really well, so far I haven't blow up my oscilloscope terminator yet. I'd say it's the go-to choice for high-voltage pulse measurements if you don't need higher input impedance. #electronics #usb

   • niconiconi (niconiconi@cybre.space)'s status on Tuesday, 25-Jan-2022 05:06:12 UTC niconiconi

     in reply to

     shorted to ground, now it's completely dead.

   • niconiconi (niconiconi@cybre.space)'s status on Tuesday, 25-Jan-2022 05:06:13 UTC niconiconi

     in reply to

     BTW, the USB Killer appears to have successfully destroyed my 20 dB RF attenuator during the test. :blobcatgiggle: #electronics