I have a project for school where I needed to make an invention, and I chose to make a curtain that automatically closes when it gets dark outside. Except I don’t know a lot about electronics and it needs to be as simple as possible. I asked chatGPT for a list of things I need and it told me this: Would this work?

I can't seem to find the answer to what kind of plug this is, looking to install an aftermarket light in the tailgate of my 2025 Subaru Crosstrek but the plug isn't the same, looking to find one that will work with this adapter and solder it onto the light I have.

Hi All - been a while since I tried to work on circuits at this level, but the attached is close to what I need. This allows long delays (not necessarily accurate but doesn't matter in this application.) Pulled this off of: https://homediyelectronics.com/basic/longtimedelays/

Now, this circuit, the output starts off high, when the button is pressed, it goes low for the time designated by RC, then goes high again. If the button is on all the time, the timer doesn't start.

I am trying to modify this and keep the long time delay, but instead of timing when power is removed (button off) I need to time when the power is ON. Like a typical monostable setup on a 555, but with the transistor controlled trigger that allows for long delays with low C.

I prefer to stay with 555 timers at this point for this application.

Any suggestion is appreciated!

Hello, I am looking for relay or conductor. That can handle switching DC voltage without disconnect arc and is controled by AC voltage. I was googling for ages and cant find good cheap product. Thank you very much. Sorry for my english, I am not native speaker.

How can i weld these ? Is it even possible ?

hey! i have this collectible doll that’s supposed to play music, it stopped working suddenly and when i opened it the speaker got loose. there’s super thin copper wiring with two strings but one of them broke. is there a way to replace it

I bought this led strip off temu for a couple bucks I want to put it in my closet to light up when I open the door like a refrigerator currently it only turns on with a remote.

Hello I am trying to create a circuit where you turn on device by momentarly pressing button then microcontroller inside tecides, when to turn it off.

I have devices working off of couple voltage levels, so I've decided to control it from negative side. I have decided to use mosftet as it theoretically draws no/very little current when on (as compared to relay). I short mosfet for device to boot up, then microcntoller pulls it's gate high. then to turn off it pulls it to high impedance (pulling it low didn't work, so i added resistor connecting to ground and changed to high impedance)

In the photos I present both simplified and full schematics.

I have noticed that sometimes device turns on partially (lcd backlight turns on and speaker is clicking, but nothing else) so I vent to investigate.

here is what I found. Mosfet when it is supposed to be off is partially on. and when battery is charging or fully charged, voltage behind it is high enough to turn rest partially on.

Here is voltage readings

Turned off:

Battery 7,3V GS 3V GD -0,5V SD -3,5V Regulator High side 3,8V Regulator Low side 1,6V

Turned on:

Battery 7V GS 3,5V GD 3,2V SD -2,8V Regulator High side 6,7V Regulator Low side 5.0V

Charging:

Battery 8,1V GS 3,3V GD -0,45V SD -3,75 Regulator High side 4,7V Regulator Low side 1,9V

Charging, partially on:

Battery 8,3V GS 3,25V GD -0,45V SD 3,7V Regulator High side 4,6V Regulator Low side 3,15V

Now my question is, what is causing it, how should I do this kind of setup properly, can I do it properly with mosfet or i need some form of insulation either by relay or by transoptor?

thank you in advance for any help

After creating this "worst contraption to power anything ever" out of 4 LEDs connected in parallel and a generic 2032 battery holder I needed as a light source, I'd like to know how these things are done properly: are there any common approaches to designing a "standalone light module"?

Ive recently been working on a lot of old tech that likes to do the above mentioned and I want to get a respirator for it but I don't actually know what Id need to filter, and I cant get any concrete answers onlne

The first problem is that the chip thingy that connects to the speaker broke, how do i fix it, i don't know much about speakers in general, so can i just glue it back or something

The second problem is that, after charging i have to either short the two pins, the charging pins to make the earbud work, i mean why do it need to be short for it to work

and thanks in advance,

Hello,

I have scale from china and it does have RS232 "output" on pcb. However the output is only 5 volts and is looking very weird? Am I using pulseview and logic analyzer properly?

I’m a working on a hobby electronics project where I’m trying to interface a modern GPO746 rotary phone with an Arduino Nano to play MP3s using a DFPlayer Mini based on what number is dialed. I’m a beginner 🥵

This phone doesn’t use the traditional pulse-click dial method that old rotary phones use. Instead it has a “rotary encoder disc” with 8 output wires labeled R1–R4 and C1–C4, and a disc with gold contact pads that get touched by metal spring arms that drag along the strips when you dial.

Here are some close-up photos of the internals: • The dial cap with metal contacts:

• The contact disc underneath:

• The side showing labeled R/C pins:

• Full view of the ribbon cable going to the main board:

What I’ve learned so far: • When I connect C1 to GND and read R1 from an Arduino pin, I rarely get a successful digitalRead LOW when dialing certain numbers — so some kind of matrix contact is happening but not consistently. • My current plan is to test combinations of R and C wires to identify which digit corresponds to which pair.

My questions: 1. Does anyone recognize this dial/contact pattern from a rotary or keypad matrix design? 2. Is there a standard or known way to interpret this 8-wire combo? 3. Any tips on reliably detecting contacts with Arduino?

Any insights would be super appreciated. I’m learning as I go.

Hey all, for a small project at school, I am required to try to create a PCB with an ESP32 as the heart. The battery is an 8.4v liPO and the hydrogen interface is a hydrogen generator. The two INA219AIDCNT's are there to detect the voltage over the battery and the voltage + current over the hydrogen generator. the rest of the PCB is two circuits powering off and on two solenoid valves. and one switch sensing circuit. i was just wondering whether anyone could quickly look over the schematics and give me any points

Thanks

Hello, as the title says I want to measure the average DC positive voltage of an AC drive waveform for a grid of a vacuum tube (I know the flowing average current ~0.522 so i want to calculate my grids dissipation P = U * I)

Frequency: -1.4 - 2 MHz

Amplitude: -Negative peak ~1.5kV, -Positive peak probably? 0.65kV

Signal shape: -shifted Sine Wave, positive peak smaller than - negative peak, Class C oscillator drive signal. - Positive cycle is <180°

For that I have soldered 22 1N41448 diodes in series and used a moving coil DC voltmeter. (0-400V DC)

It measures just a bit over 0V around 20-30V? that is impossible, adding a 1nF capacior across the meter changed it to show 240V DC which makes more sense. If i use a larger capacior the reading changes to be more positive. I have also tried moving iron voltmeters and the readings are slightly different +/-20V or so with having both referenced with a DC source.

Thing is that "filter cap" obviously falsifies the reading since it doesnt measure the average anymore but the near peak of the waveform.

so my question is how could i use an analog voltmeter to measure the average positive grid drive waveform, or how would i compensate for the pulsed DC coming from the rectifier which my analog voltmeter is too slow to respond to?

I cannot use my oscilloscope since my probes cannot take the full amplitude of the circuit and would be damaged, even after the rectifier, it also falsifies the reading by the probes capacitance and i would still need to figure out the average voltage.

I can give more information on request, thank you.

Left picture is the best representation of the setup I'm going to be working with, right is what I see everywhere and wish dearly I had. Description below for the left picture.

I have been given the amazing task of coding in python the communicating from a RPi 4 to a bunch of STM32 by CANBus. The whole thing is already built by some people that are long gone, sweet... Never done that before but eh, I played some factorio so I know what bus is right?

The things that is completely stumping me and my colleges is the way these the whole thing is setup:

-Each STM32 is on his own PCB, so far so good. Each PCB is about 2 inches apart btw.

-The CAN_H and CAN_L Bus is immediately "stopped" at the first PCB, by that I mean it goes into a MCP2551 CAN transceiver with the mention "CAN_IN" on the board. uh???

-Each PCB has its own CAN_IN CAN_OUT, so 2 MCP2551 per PCB. Kind of a cascade instead of a bus?

I will have access to this amazing piece of engineering in about a week, so I am simply wondering what to expect on the side of communication. Are these... relays..? going to affect how I communicate with the 4th STM32? It feels like the nodes are between many small busses? Or should I treat this as a normal CANBus where each node receives the message and only the one with the right CAN_id actually read it?

Forgive the snark, I would be really happy to be proven wrong. Is this left side setup overly complicated like I think it is? Or am I the fool?

Thank you

I need a high side switch to output 5V when a 1.8V logic signal is HIGH on its input. I bought the TPS22919 but it's not passing V_IN with 1.8V applied to ON pin. I'm looking at https://www.ti.com/lit/ds/symlink/tps22919.pdf and now wondering if V_IH is dependent on V_IN and if 1.8V is insufficient when supplied with 5V. Should this work, and if not what's the simplest arrangement?

This is to supply a bias voltage for an active GNSS antenna which draws about 20mA, I'm switching the supply to save power between locates.

Hey, I'm looking for a 2200uf, 56v (or above?) Capacitors for a 90's HI-FI amplifier repair but finding these strangely hard to Source. I'm in the UK, but guess to the wonders of international postage I can order from anywhere.

Thanks in advance

I am working on a lightsaber project with an arduino. Im using 2 144led argb strips for the blade that run at a max of 45w and run at 5v. I have an 18650 battery that provides 3.6v so i needed a boost converter to make it 5v. I got this XL6009 which seems to work well and provides me over 3amps which is fine for the brightness and length of the strips I need, but its getting really hot when leds are powered.

I was wondering if this is dangerous in any way or if it will cause issues. This is what I got (https://www.amazon.co.uk/DollaTek-XL6009-3V-32V-5V-35V-400KHz/dp/B07DJ4F1BN).

Thank you.

Also, wondering if this board is even needed, the lights work just fine when powering without the board.

Wondering if this board has an accelerometer. I know nothing about this and this is why I’m asking. Also what is the gold cylinder? Any help is greatly appreciated.

Hello, I’m extremely new to this. New as in I’ve never built anything. I’m interested in making a voice box for a Phantom of the Paradise cosplay, and I found a tutorial online.

https://www.instructables.com/Phantom-of-the-Paradise-Voicebox/

Would anyone mind helping me find the correct parts listed here? The ones without links, I mean. Also, does anyone have any advice on good tools to start out with?

Thank you so much!

The shown circuit is an LLC resonant converter. It produces an inductive kickback from the primary winding (50mH) and that creates a negative current through the 12V source, seen in the gif. Is this bad for a high current rated LiPo? I plan to install this converter with a 6200mah 120C 3S LiPo battery (bomb) in an aluminum chassis for portable power. I am wondering if i need to install additional components to absorb the kickback, preferably without wasting much power if that is the case. Thanks

Am I right to assume this Is a 0.68uF cap? I Need a capacitor with that value but before using It I wanted to be sure, can't find anything on the internet when I type in the code. Also, what voltage rating am I looking at here?

This is a fridge light for my small 12v camper fridge.

Problem is, it stays on when the door is open, no way to turn it off (I need to leave the door open between trips, dry the fridge out, no mold).

I want to add a little inline button, between this 2 pin male/female connection.

I've had a search, there are a load of different types. Does anyone know? And any ideas of best button/switch I could use for this?

Thanks :-)