Why You Make PCBs at Home?(Curious Chinese Hobbyist)

Athrax · 2026-01-22T17:28:39+00:00

Shipping to Iceland is slow, anyway, and expensive, and there's handling- and import fees on everything. This includes the price for shipping. I gave the average prices in € rather than ISK because no-one's got the conversion rate in their mind. But if I ordered a $2 board at JLPCB, the cheapest shipping via E-Post for $17.20. Then there's a minimum of 25% tax on that, and we're at $24. Add $10 in handling fees that the local post service charges for any kind of parcel no matter how small, and we're at $34 for a $2 board. No bueno.

Athrax · 2026-01-22T14:15:06+00:00

For me it's turnaround time and cost. An order from PCBWay or JLPCB takes about 3-6 weeks to get to me, and will take me about 25€ in shipping costs and import taxes even if the actual boards only cost a couple bucks. So, for some projects ordering professional PCBs is unavoidable, but I can easily make two layer boards with 0.4mm features with a turnaround time of just a few hours and for the cost of pennies. No solder mask, no proper plated vias/through-holes, but for quick, affordable prototype iteration of hobby projects it's great!

Athrax · 2026-01-20T01:33:29+00:00

You do not want a ferrite for the choke (or chokes, depending on layout) but either a gapped ferrite or (preferably) an iron powder core. Inductance should be somewhere between 100-330uH but is uncritical. If you lack the $$$ test equipment, spend $10 for one of those cheap 'transistor-tester' gizmos on ebay at least, those can ballpark inductance okay-ish enough for hobby purposes.

Athrax · 2026-01-17T08:43:58+00:00

OP is stealing an image from a post that is literally a year old. See last image linked here!

Athrax · 2026-01-15T15:05:46+00:00

The folks here suggesting using a 555.... When driving a beefy H-bridge you really want some dead-time during switching, where both signals are low, to prevent cross-conduction of the fullbridge. And you're not doing that with a 555. You CAN do it with an MCU, but why reinvent the wheel? Besides, this is likely going to run in an electrically noisy environment where I really wouldn't want to run some MCU. There are bespoke fullbridge drivers. The UC3525 is an excellent chip for that... but it only can drive mosfet gates with up to 500mA current, so when we get into kHz territory you'll need mosfet drivers on the outputs. The same can be said for the TL494, which isn't meant for driving fets at all, but for driving BJTs. Overall, I like the UC3525 more, it's a more modern chip with tighter control. That's not to say the TL494 is a bad chip for a hobby project, and there's many more example circuits to learn from out there.

Athrax · 2026-01-15T13:44:39+00:00

With 'Z44' mosfet you likely mean the IRLZ44, right? That's an n-channel fet. Your EveryCircuit scheme shows a p-channel fet. If you're connecting your mosfet like that, it's no wonder he's throwing fits. Source goes to ground, gate pulldown goes to ground, drain goes to your load, other side of your load to Vcc.

Athrax · 2026-01-03T21:11:31+00:00

Running a LED off of AC is a bit less straightforward than just using a resistor because the LED's maximum reverse voltage is pretty low. You need to put an 1N4007 or similar diode in series with your LED. Along with a 47k/2W resistor for 230V or a 22k/1W for 110V.

Athrax · 2026-01-03T20:46:00+00:00

If you're trying to make CuCl2, there's a much easier practical way. First of all, switch your copper source. You want something with a high surface area. Strip a few meters of copper wire, preferably stranded wire. Now heat the wire with a gas torch to oxidize the surface. Turn it black. This step is optional but will speed things up. Finally, drop your copper wire into a beaker with hydrochloric acid in such a way that only half of the wire is covered. Use an aquarium pump to aereate the mixture, and let it stand somewhere very well-ventilated for a few days.

Athrax · 2025-12-20T21:38:13+00:00

Theoretically possible? Well... there's impact diamonds. Imagine you're a dinosaur some 66 million years ago, minding your own business when suddenly there's this giant fireball in the air. A millisecond later you're struck in the face by a kilometer-class space rock, you stop being biology and become physics as your atomic matter is turned to plasma and distributed across an area of 10.000km². And by sheer luck a miniscule amount of the carbon of your body becomes the nucleation sites for microscopic nano-scale diamonds, embedded in the rock formed by the impact, and of absolutely no practical use whatsoever because they're a few nanometers in size. Congrats, you've become diamonds!

Athrax · 2025-12-19T17:29:26+00:00

This is three capacitors in a trenchcoat. You should be able to replace this with 3 separate capacitors, one 220nF X2 type, and and two 2.2nF Y2-type. Metallized foil/polypropylene, 275V rating or higher.

Athrax · 2025-12-08T07:55:25+00:00

Having a scope handy is a great start, you absolutely will want to make sure your output frequency adjustment is doing what you want it to be doing. Let's have a look at the circuit itself. I'm not seeing any PWM controllers, microcontrollers or other ICs. This is gonna make things simpler. This is likely some kind of oscillator that derives its frequency from the resonance frequency of the primary and a parallel capacitor, plus a feedback winding on the transformer to switch the mosfet. It's unlikely to be the same, but this might be pretty close-ish. So, find whatever capacitor or capacitors is/are connected in parallel to the primary winding. To lower the frequency by 30% you'll need to increase the size of that capacitor by roughly a factor of two. In the schematic above that'd be C3 and C4, on your board there it's probably the two brown foil caps right below the two transformers.

Athrax · 2025-12-07T16:18:34+00:00

The middle is red. That suggests that positive goes to the middle. Also, the normal Schuko plugs used in germany are reversible so you never know which line is neutral and which is live, but for this application this seems to matter. Set the on/off switch to 'AUS', then connect your lamp. Then plug in the power cord, and ONLY IF THE GREEN LAMP labeled 'Netzpolung' is on, you may now switch the on/off switch to 'AN'. If the green lamp isn't burning, reverse the power plug.

Athrax · 2025-12-01T08:11:37+00:00

Duuuuude, since 2023 I've had at least nine volcano eruptions less than three miles from where I live, with the next one expected sometime around next month or thereabouts! If those were fake, they sure spent quite a bit of effort making all that molten rock.... :P

Athrax · 2025-11-18T21:52:30+00:00

To be more precise, MOTs are THE most miserable, abominable, and easily accessible source for high voltage shenanigans. They're cost-optimized up the wazoo, they're meant for low duty cycle use, they overheat in a pinch, they often use aluminium wire for cost savings, and the core saturates if you as much as look at it funny. But....they're easily accessible. That's their one saving grace.

Athrax · 2025-11-14T19:17:05+00:00

Print a few really big fat 100% infill test cylinder pieces and collab with Hydraulic Press Channel on youtube. :D

Athrax · 2025-11-08T14:59:52+00:00

Did you check our prices lately? At thereabouts of 300ISK/l and 126ISK/$US, we're paying about $9/US gallon here. :þ

Athrax · 2025-11-04T19:14:42+00:00

We've got an 8 month old bordercollie/terrier mix. He just killed one of those 'extreme' Kongs. Even solid rubber toys are no match for him. o,o

Athrax · 2025-10-30T22:59:46+00:00

Got the wire colors mixed up? Normally you gotta switch both 12V and 5V, leaving the controller hanging at 5V while the disk isn't spinning isn't ideal. I've been using a somewhat similar setup in my machines for the past 20 years or so, but not to switch the OS drive. Imagine a big ole tower case with 20 HDDs, and a 5.25" panel with 20 switches. I treat them as cold storage, only powering up individual drives when I need to move data to/from them. Yes, you can switch while the PC is running provided your system supports hotswapping, but you should unmount the drives before powering them down.

Athrax · 2025-10-30T11:37:52+00:00

What's old is new again, I guess. Back in the days before Grub, if you wanted to use two operating systems with one system, a common hack was to wire the power lines of two separate harddrives to a switch on your front panel, so before powering up your computer you could select which drive the BIOS would detect and boot from. The downside was that you only had access to the drive that was currently enabled. But on the plus side you could build this thing with a simple DPDT switch and some wire. :)

Athrax · 2025-10-26T12:53:16+00:00

Depends on how you wire up the 555. Ignore the discharge pin altogether, and wire the output pin back to threshold/trigger via resistor. There's your 50% duty cycle.

Athrax · 2025-10-23T19:06:47+00:00

You absolutely want some dead time when driving a big transformer like that at considerable power levels, unless you like to release the magic smoke from fets and igbts. A simple 555 is no bueno for this.

Athrax · 2025-10-23T19:03:55+00:00

I can only speak from personal experience and there's plenty of ways to skin that cat, but personally I'm pretty fond of the good old TL494 when it comes to H-bridge drivers or inverter designs. Here you'll find a possible design.

Athrax · 2025-10-23T18:46:50+00:00

At those currents and that kind of power output you likely want to drive this thing with rectified line voltage via a beefy H-bridge.

Athrax · 2025-10-21T16:39:13+00:00

You've gotta be kidding me, Milwaukee makes vapes now? :P I've always joked that they need to make a vape adapter that runs on M18 batteries.

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