I read that aluminum electrolytic capacitors stored without being energized for a long time present many types of failures

Does the energization time of the aluminum electrolytic capacitor influence the time it can be stored without being energized safely? For example, I energize the aluminum electrolytic capacitor for 30 minutes vs. another aluminum electrolytic capacitor I energize for 60 minutes, can both be stored for the same amount of months or years? For the same temperature and same humidity, for example, 35C 58-67%

I did made a PCB whose schematic is shown above. This uses a module of ESP-32 Wroom instead of a Devkit but the issue I am facing is that the Port in not getting Detected. What can be the solution for this?

Hello, can you help me? Look, I have mounted this circuit on a breadboard but when I energize it, the buzzer sounds non-stop. I am using an Arduino mq6 gas sensor module. I don't know if there is something to it.

I have all the materials listed here, I don't know if it is something at the time of connecting it or what I should do to stop it from behaving like that, in fact, when there is presence of gas the buzzer should be activated

https://preview.redd.it/edm2778byi3e1.jpg?width=1080&format=pjpg&auto=webp&s=0f37146635a80b7d6f855f8a515eecff70ff1241

I have little experience with electronics but I got one of the Amex radios at Vegas last week and wanted to see if I could access any other radio channels than the preset ones, currently it only has 2 presets selected via the two buttons on the left. Any ideas on how to change it or what to do for fun with it instead? Any info on what I’m seeing helps too. Thanks!

I have some basic understanding of electrical things and can solder quite well. But Z-diodes are a bit too advanced for me. I wonder if someone can assist me with a solution to my task:

I like to power a 3V LED. Using only two 1.5V batteries would led to the LED become less bright over the time whilst the batteries lose their power (they probably die around 1.2V, I think).

My tests show that I can send the full 4.5V to the LED, and while it won't get brighter (compared to the max brightness at 3.2V), it will consume more power because the amps go from 50 mA at around 3V up to 200 mA at 4.5 V. I like to avoid wasting that much energy because it'll drain the batteries much faster, which isn't good.

I like to find a way to use the 3 batteries to power a 3V LED without wasting too much energy. Is that doable? And with low-cost materials (I like the circuit stay below $1 - it will be all encased in a 3D printed box that I'm building, with a switch, as a small light for lanterns – you know, xmas time).

So I thought of using three batteries and then use a Z-diode to limit the voltage to 3 or 3.3V. But what I don't understand: Will this still consume 200 mA when the batteries are full, or will this save the power as intended, while keeping the LED at max brightness (around 3V) until the batteries suddenly die?

And if that can work, how do I calculate the resistor for this? Also, will a 0.5W diode work here, or does it need to be tougher? Not sure where the 0.5W limit comes into play. After all, there'll also be a ~10 ohm resistor in line with the diode, right?

I have a monostable 555 circuit and I want to know is there's a way to modify it so that it not only triggers the relay when the voltage is supplied but once again when the voltage drops?

I have built the following H bridge for driving my 48V 500W spindle for my DIY CNC Mill. The optocoupler part works well and I started to test the H bridge, however the transistors are heaing up like crazy even without load on the motor. It feels like 70-80°C after a few seconds of starting the motor. It was only tested with 20V and maximum 0,5A.

What could be the problem and how could I solve this? Do heat sinks count this much? The transistors are: https://www.hestore.hu/prod_getfile.php?id=9060

https://preview.redd.it/e6i01cgj933e1.png?width=1102&format=png&auto=webp&s=c5883a92c17c240874cdf00c11c89e87d19e8950

Opamp circuit on a pcb from the 80s in repairing, any idea what the red and green components are in this photo? The green one looks like a cap? But it’s text seems to indicate it’s a resistor? The red one I have no clue at all…. Any help would be nice

This pcb is part of charge circuit on a 24 volt 2,2Ah lithium battery . I found this diode shorten the charge lines -/+. This diode is 33A type, which specified as 24v 400W. The charger is 24v (7s) 24watt, so what is the purpose of using a 400W diode?

Hi everyone,

I’m building a "Smart Climbing Wall" where each climbing hold lights up with an LED and has a button to press when you reach it.

I’m thinking of using piezo sensors as the buttons, but I’m not sure if they’ll last long or if I’ll need to keep fixing them all the time.

What do you think? Are piezos a good choice, or is there something better?

https://preview.redd.it/4znfwdstb72e1.jpg?width=1600&format=pjpg&auto=webp&s=5864e0894c65a5100ffb7c86e138ceaf54ef1b7a

Hey everyone!

I inherited a cheap Chinese dash cam from my brother in law and Im having a problem where when I turn the car off, the dash cam immediate shuts off and whatever video it was recording gets immediately corrupted.
I dont have much electronic fixing background outside of soldering a new battery into my headphones but I thought maybe this could be a bad capacitor thing?

I took the dash cam apart and there were two identical 3.3V 2.7F capacitor and I took their resistances. One was showing around 18 MOhms and the other I couldn't get a reading from. There wasnt any visible damage to the capacitor.

I just wanted to see if anyone had any advice on whether or not this sounds reasonable to replace the capacitor or if im being stupid hahah.

I know the better thing to do is probably just buy a good quality dash camera but Im trying to learn to be a fixer and DIYer
Thanks!

https://preview.redd.it/b8zwngkhmx1e1.jpg?width=1920&format=pjpg&auto=webp&s=e76e4042b2844c5ffbc9acfece3157e63f1b5b71

I need help identifying this flex cable. All I know is that it has 20 pins, its pitch is probably 0.3mm, and that it came from a 40 year old Japanese typewriter (Silver reed EX 30). The alphanumeric code printed on this cable is FJK EF-20 94V-0. I need help replacing this cable as it is frayed and not able to establish an electric connection.

Hello! I have this capacitor that I need to replace. From research I see it is 33pF 100V. When I try to find a replacement on mouser, they seem to be automotive. Does anyone have a suggestion of what would work?

I was trying to fix a stick drift issue on my PS5 controller and ended up going as far as opening the potentiometer and cleaning it. I have essentially no experience with this stuff but from the info I can gather online I’m thinking this one might be used to the bone and good for the trash. Any thoughts or advice?

Hi all, I am attempting to simulate the impact interference from an external source has on a 4-20mA Circuit. I have tried getting to grips with ANSYS circuit/HFSS, but I am still hopeless. Is there any simpler software that I could use? If not, does anyone have experience with ANSYS (I have a few questions)?

https://preview.redd.it/v1fzpta2il1e1.png?width=858&format=png&auto=webp&s=e84cd33e76cd21b47cba74ea7482a7ed0b266951

Similar to this I want to connect the wires to the board but I don't have the connector bit on the end (just bare wire) Please help as I need this for a project due soon.

Hello everyone,

I'm struggling to create a circuit that inverts the polarity of a string light. The string lights have only two ends. I have a 555 timer that uses a potentiometer to trigger a signal every a few seconds. Is this possible using Diods and the timmer?