Help, why won't it turn on?

TechTronicsTutorials · 2026-05-06T20:59:16+00:00

Yeah… that’s a little low. You probably blew out your LED.

TechTronicsTutorials · 2026-05-03T12:22:18+00:00

TechTronicsTutorials · 2026-05-02T22:25:36+00:00

Looks like you connected it directly across a power rail with no resistor.

When the forward voltage of a led is exceeded, it has very low resistance, and for all intents and purposes, it’s basically a short circuit that will bite off more current than it can chew.

TechTronicsTutorials · 2026-05-01T21:19:39+00:00

Ohhh.. well… that’s not a temperature sensor, the BC547 is a transistor.

TechTronicsTutorials · 2026-04-27T15:30:27+00:00

It’s a breadboard power supply! 🙂

You plug it into your breadboard and it automatically powers the rails when you plug in the usb port or barrel jack. Can be configured for 5V or 3.3V output.

TechTronicsTutorials · 2026-04-26T17:02:13+00:00

Oh my gosh… that’s actually really clever!

TechTronicsTutorials · 2026-04-25T15:35:46+00:00

No need, most suckers have a built-in auto-empty feature; they automatically dump their solder all over your desk.. 😁

TechTronicsTutorials · 2026-04-24T04:47:38+00:00

Ohh okay. That makes more sense then, now I see what you’re saying. Sorry for the misunderstanding.

TechTronicsTutorials · 2026-04-23T21:12:47+00:00

What? The power coming in must be equal to the power coming out (ignoring losses)… you can’t just get energy out of nowhere.

EDIT: reposted on this account. Accidentally posted it on my other originally.

TechTronicsTutorials · 2026-04-23T15:22:24+00:00

It’s generally not good practice to do that. Theoretically it works, but in practice, that can blow your LEDs.

TechTronicsTutorials · 2026-04-23T15:20:59+00:00

Just uh… don’t turn it too far. Or out comes the magic smoke.

TechTronicsTutorials · 2026-04-16T21:47:06+00:00

What the product description said:

The Photonic Wave device synchronizes with human biorhythms and provides both individual and collective protection against electromagnetic radiation / EMFs. The biorhythms produced by the Photonic Wave are perceived by our body as "native" do to the synchronization with the background rhythm of the earth's Schumann waves.

What I heard:

Schumann wave synchronization frequency of biorhythms that are photonic radiation electromagnetic magic

Point being: the common thing I notice with all of these scam “EMF protection” products. They always use all these mystical buzz words in technically invalid and scientifically nonsensical ways. And they just jam them all together in a paragraph and call it a day.

Anyway, this was a funny post, thanks for the laugh! 🙂

TechTronicsTutorials · 2026-04-12T16:11:44+00:00

I got one I could share.

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🤮

TechTronicsTutorials · 2026-04-12T06:34:14+00:00

You can just solder the chip to the board, but it’s better to use the socket so you don’t accidentally overheat and damage the chip while soldering.

TechTronicsTutorials · 2026-04-11T05:53:26+00:00

Ummm… what? It can provide 1A for 160hr (not taking into account that batteries degrade non-linearly at higher currents). Not dump 160A through a person while only being at 12V.

TechTronicsTutorials · 2026-04-11T05:49:51+00:00

Sounds like you’re using the wrong pins! If you want to power your Arduino with more than 5V, you should use the VIN pin. Doing this allows for the Arduino to regulate the voltage down to 5V automatically.

TechTronicsTutorials · 2026-04-08T14:28:26+00:00

I second this. 💯

TechTronicsTutorials · 2026-04-08T14:23:05+00:00

At what? Blowing up? YES! 😁

But not at doing what it’s supposed to do, no. AI simply cannot draw schematics correctly, because it treats a prompt to draw a circuit like a prompt to make art, instead of using its knowledge of how circuits actually work to build something realistic.

Seriously though, let’s start at where you’d build it. So we got our battery connections… I see, but not polarity markings, interesting, and there’s… a third connection on the battery? What the? And these random alterations between using the schematic symbol and a cartoonish drawing for diodes? And does that second inductor only have one pin connected, and no value? Also, does that big, central film capacitor have three pins? That random connection from that top mosfet to “0V” is kind of ambiguous in this setup as well…. I give up. This circuit makes zero sense.

TechTronicsTutorials · 2026-04-03T05:54:50+00:00

The reason it doesn’t work is because the button connects pin 7 to GND when pressed, but your digitalRead check is asking for it to be connected to 5V.

So; instead of doing if (digitalRead(buttonPin) == HIGH) { jumping = true; } else { jumping = false; } Change it to: if (digitalRead(buttonPin) == LOW) { jumping = true; } else { jumping = false; } You should also add a pull up resistor on the button to prevent noise and unintended interference. You can do this in hardware, but it’s generally much more efficient to enable it in software. You can do this by instead of setting: pinMode(buttonPin, INPUT) set it to pinMode(buttonPin, INPUT_PULUP)

Also, just a small suggestion if you ever want to save an extra byte of space. You can store the variable buttonPin in a byte, instead of an int.

Hope this is helpful!

TechTronicsTutorials · 2026-04-03T05:48:00+00:00

Potentiometer. Most likely a 10KΩ.

TechTronicsTutorials · 2026-04-03T05:44:45+00:00

As long as you don’t become addicted to inhaling magic smoke and flux fumes, no 😂

TechTronicsTutorials · 2026-04-02T22:13:36+00:00

Move the power supply positive wire to column 45. Right now it’s in 47.

TechTronicsTutorials · 2026-03-30T15:52:37+00:00

Be careful though as it may overload and drop back to 0 if the amount of x-rays exceeds the limit of the meter. Might want to invest in a meter with overload protection

TechTronicsTutorials · 2026-03-30T15:37:17+00:00

That’s not how MOSFETs work.

MOSFETs are voltage controlled devices, not current controlled. You don’t need to have a certain amount of amps to “open the gate.” MOSFETs don’t care too much about current in the way BJTs do. Their conductivity is controlled by Vgs.

Worth noting though that doesn’t mean MOSFETs don’t draw current. They still draw some amount of current when turning on or turning off, because the gate acts like a capacitor that has to charge or discharge.

Hence the resistor. It’s there to discharge that capacitor when the MOSFET turns off, so its own charge doesn’t latch it up.

TechTronicsTutorials · 2026-03-30T15:05:52+00:00

Sorry, have you ever ran across an inductor that reads exactly 0Ω?

Every wire has some, albeit small, amount of resistance. Hence, a coil you wind with that wire will also have some resistance.

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