What type of switch is this? (Poles and throws?)
u/Classiceagle63 — 2 days ago
r/electronic_circuits
Do old resistors really go bad after years sitting around?
I found this tiny old electronics shop nearby and the owner let me look through a back room full of vintage components that have probably been sitting untouched forever. Buried in the shelves were a bunch of Vishay Dale resistors still sealed in old packaging from around 2005 according to the codes.
The guy offered me the whole box for pretty cheap and now I’m trying to figure out whether old resistors are still worth using after sitting around that long. Part of me feels like resistors should basically last forever if they’ve never been stressed in a circuit. Then another part of me keeps reading stories about moisture, corrosion, and drift affecting older components over time.
I’m still pretty new to electronics overall, mostly practicing soldering and building simple kits so far. I even checked discussions involving old stock component inventories from online marketplaces electronics suppliers because I got curious how many “new” parts online are really older surplus inventory.
For people who’ve used older stored components before, do old resistors usually stay reliable for hobby projects after decades sitting unused?
u/CherryTraditional733 — 6 days ago
Electron tubes for high frequency generator
I need these tubes for a HF generator. Nowhere on the internet to be found, i tried searching on the internet by the label but i only found the information on the fourth picture. Anybody know where these could be purchased? If possible on aliexpress
u/imam23jku — 4 days ago
fast blow or slow blow fuse for a motor driver circuit
I am designing a small DC motor driver circuit using a 24V power supply. The motor draws about 3 amps normally but has a start up surge around 8 amps for maybe half a second.
I am trying to decide between a fast blow and a slow blow fuse. I have looked at both types on typical affordable sites like Amazon, Alibaba, and eBay. Fast blow would probably trip every time I start the motor.
Slow blow might protect against shorts but still handle the surge. But is there a risk that a cheap slow blow fuse reacts too slowly if something really goes wrong?
I want to protect my components without nuisance tripping. For those who build motor circuits, what fuse type do you normally use?
u/0Trent — 6 days ago
OV3660 camera connected → 1.5V LDO gets extremely hot on ESP32-S3 custom board
I’m designing a custom ESP32-S3 board with an OV3660 camera sensor, and I’m facing a strange power issue.
The moment I connect the camera sensor through the FPC connector, my 1.5V LDO starts getting extremely hot within seconds.
Without the camera connected, everything seems normal.
u/Aadarsan1234 — 8 days ago
CO2 monitoring system w/out microcontrollers
help! we created a co2 monitoring system using 2 MQ-135 gas sensors. the catch here is we were tasked not to use any microcontroller and instead opt for ics. we used lm358 as the averaging amplifier and lm3914 as the driver of the leds.
we tried prototyping it using a breadboard and it works fine! the issue here is after implementing it to a pcb and soldering all the components, it doesn't work as intended now. the white led (lowest ppm) always turns on but so as the yellow led
attached is our current schematic.
u/hanasamaaa — 11 days ago
Can I test this P channel mosfet in circuit?
I replaced this mosfet but not sure if I damaged it in the process. The fan won't stop spinning whereas before I replaced it, it wouldn't spin at all.
Can I test this mosfet (Q1A) in circuit? Is there a link on how to test p-channel? Thanks
u/zangief1977 — 13 days ago
Stereo Amplifier Burnt PSU?
Hey guys and girls I have recently brought a new Technics amplifier SUX102. I have been using the system for a couple of days and I throughout it has been fine but I could always smell a small amout hot electronics coming through the AMP. I decided to take off the cover today to take a look and clean it. I found the smell is coming from the main PSU.
I had a look at the PSU and found some traces with some black ness around them? not sure if this is old burnt flux? or it's the cause of the smell? doesn't look like their is any black marks on the other side of the boards?
is this okay?
u/ToastedSandWichKing — 13 days ago