Reddit:Electronics

Was diagnosing a Seasonic SFX (mini ATX) PC power supply that blows up main fuse whenever the turn on signal was sent from motherboard. 5V standby works fine. Spend many hours probing around but could not find a short anywhere. Only once I used a larger 200w incandescent bulb in series in a dim bulb tester did I see a spark.

Turns out that once the PSU is signaled to turn on will the active PFC turn on. This boosts the dc voltage beyond 170V rectified which was enough voltage to generate a spark between the weak insulation of the PFC diode and the heatsink it was attached too. The damaged diode in the picture still tests fine with multimeter.

I made simple annoyatron and inspired by an youtube video I have hidden it in a walnut shell. I was so excited about it working, that I decided to imagine it as legitimate product. I can't wait to do another projects 😁

Just a Cheap 8x8 smd led board. It will be a pain soldering all that leds on right position by hand.

The IC seems to be a eeprom. The MF condenser fell of the table and I was able to find it (A miracle).

Should get the boards hot and crispy plenty fast with 70W of heating :)

This printer pissed me off. Screw him. I spent so much money on this thing. Print head. $250. Ink refilling kit and ink cartridges. $100. Twice. Ink, ink and more ink. This fucking thing takes 8 ink cartridges! Bought 13x19 large format ink jet photo paper…couldn’t use because the print head SUCKS! AGAIN! Bought another print head from Ali Express $160. It’s used and not new! And inconsistent print quality.

So I did what every sane person would do. I took that thing and ripped it to shreds. I’m redacting the make and model of this fucking thing, because I don’t really want to shit on this brand. It’s a good brand; it’s just my situation that sucks. I’m part of the reason why this printer sucks, not the brand. Being cheap and all, buying print heads from Ali Express, ink and refillable cartridges from eBay. It’s because the ink cartridges are insanely expensive! I wasted an entire set of manufacturers ink cartridges (8 of these cunt cartridges!) from cleaning the fucking print head! That’s why I bought cheap refillable ink from eBay. Then the print heads decided to go on vacation, and now we’re here.

So fuck it. I tore that shit apart, and from the magic of ESP32 modules, H-Bridge L298N motor controllers, and a little bit of code, I’m turning this thing into something even more useless and retarded. Because I’m mad. And, because I really hate throwing stupid shit like this in the trash.

First order of the day. Taking that SMPS power supply that came with the thing and fucking it up. Cracked the case open, plugged it in, force enabled the output, and putting it on an electronic DC load and driving it hard. The output is rated for 32v 0.7A. Screw that. With the DC load, I squeezed out 32v at 5 amps. 125mv RMS ripple at full load is crap, but I don’t care. As long as I can overvolt its fucking motors with using the original power supply, I’m happy. Doing my best to not contribute to the earths eCycle waste issue by repurposing most components from this printer to make something even stupider and useless. Reduce, Reuse, and Recycle motherfucker.

One good thing is that the thermal cutoff works; power supply took a shit at 80° C. I freeze sprayed that bitch until it turned back on. Then continued to make it draw 32v 5 amps. Thermal cutoff keeps tripping; that’s ok…I have lots of freeze spray to wake his ass up. I mean, I have to make sure the power supply that came with this thing can handle the currents I plan on delivering to the 4 DC motors in this thing.

Stay tuned to what other ridiculous useless piece of shit machine I can turn this thing into.

I recently added a 6 channel sequencer in a drawer under the rack to allow on-the-fly edits of all the drum parts in one place. The control module on the left has an arduino that handles all the preset patterns, functions, and the chain of shift-registers to keep track of all the buttons and LED’s. The sequencer uses a couple CD4017 counters and some diode logic to generate the control signals for the drums. The drum board is made up of several bridged T filters and some white noise that are combined and fed to an output mixer.

The spaghetti inside is (hopefully) temporary until I can figure out a better system to wire everything together.

https://preview.redd.it/9qvdcn9024nd1.png?width=916&format=png&auto=webp&s=b2c185a945c4fd1e0479470f0633da8c0736bfb4

https://preview.redd.it/iqnzem9024nd1.png?width=736&format=png&auto=webp&s=a937b5f14b0fed90f2948330231a54c90ee4afa9

https://preview.redd.it/oxz16n9024nd1.png?width=4032&format=png&auto=webp&s=21c21f4dcce7fcea6ba0fec3afdead8116a902ca

https://preview.redd.it/678fgq9024nd1.png?width=3147&format=png&auto=webp&s=ddd474f5da27afb6066bb10b54e00e2e9f040640

https://preview.redd.it/i6c9ao9024nd1.png?width=4032&format=png&auto=webp&s=629da5bf2d5ac506c845bc73a58855d0500a0dcf

I recently made a high voltage generator that can either output around 20kv at 5mA if I use the resonant capacitor, or around 70kv at 0.4mA if I don’t use the resonant capacitor. The higher current mode, with the capacitor (image 1) creates a hot arc, whereas the lower current mode, without the capacitor, (image 2) can create much higher output voltages. I give the circuit 24V, constant current limited to 7.5A (the constant current part is very important, without the capacitor, it has to run at constant current 7.5 amps)

It uses a center tapped coil (5+5) turns on the core of the flyback and 2 MOSFETS (IRFP250N’s). The power side of the circuit (image 3) is very similar to the ZVS driver, although the rest is completely different. This uses a 555 timer to produce a square wave signal, which goes into 2 mosfet cascode drive circuits to drive the MOSFETS. The first cascade drive is fed directly by the signal coming out of the 555 timer, but the 2nd cascade drive is fed with an inverted version of the 555 output (using a BJT). That way, the second mosfet is completely inverted with the first. Using a resonant capacitor will make it extremely efficient, and give out relatively high currents, making a hot arc (image 1). This also makes it operate at ZVS, which makes its waveform practically pretty similar to the ZVS driver, although the huge difference is that this one is not self tuning/resonating, so it doesn’t rely on the resonant capacitor. Removing the resonant capacitor replaces the nice sine wave with inductive spikes. These inductive spikes, even though they only last for less than 1 microsecond, are around 1500V volts, so they can induce a super high voltage (but low current) on the output of the CRT flyback.

The actual build is shown in images 4 and 5.

I've bought these female type C breakouts a while ago to convert some of my stuff to type C from type A or Micro USB. However they've only ever worked with a-to-c cables, native type C chargers never recognized them.

There is a pair of pads for a resistor to indicate expected currents to the charger but it never made a difference. And then I've found the problem: the CC lines are connected together. In order to be compliant these lines should be pulled down (or up, if it is a power source) separately. (source)

By modifying the PCB I could isolate the two CC lines, and created a ground track right in front of the CC pins.

The second picture shows the action plan: cut along the red lines, scrape the circled areas to expose some copper, and short the original R1 pads. The third picture shows the resulting circuit (Red is VCC, light blue is GND, yellow are data lines, and green are CC lines)

After this I could solder some 0603 5.1k resistors directly to the CC pins and the newly exposed copper lines to pull them down individually as seen on the first photo.

You need some patience and stable hands, but in the end you can make these work with anything!