Reddit » Electronic Circuits
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Reddit » Electronic Circuits
18h ago
Hey everyone, I could use some advice on identifying a missing component on my laptop's display model (SHARP LQ156M1JW09, 1080p 240Hz). I recently took it to a repair shop, and it looks like they removed a component from the display circuitry, but they're now denying it. From the surrounding parts, it seems like the missing piece might be a ceramic capacitor, but I’m not entirely sure. Has anyone encountered something similar or could help confirm if it’s indeed a capacitor? Any input would be appreciated!
https://preview.redd.it/rz3grr9cjvzd1.jpg?width=4000&format=pjpg&auto=webp ..read more
Reddit » Electronic Circuits
18h ago
I'm new to electronics so go easy on me :) Context: This is part of a 24v flat inductor coil circuit using a XKT-1511 chip. I believe one of these two black square components to be toast as the unit powered off and I saw a bit of smoke come from that direction. I believe the 3 pin one to be an NPN transistor like MMBT3904 based on how it looks and the very slight marking of "1D" and some sort of horizontal T on the right hand side. This has continuity to ground on the bottom right pin. The other pins show values of around 800 on the left pin and 1500+ on the top pin when in continuity mod ..read more
Reddit » Electronic Circuits
1d ago
Help. Ive tried so many times. Cant get it to work. Just want a button that activates a few leds and a small motor. It then thrns its self off after 5 seconds. Ive tried timer 555 couldnt get it to work. And all sorts. Help
submitted by /u/FireLadcouk
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Reddit » Electronic Circuits
2d ago
The end of the wire is capped of with soft plastic, idk if this is relevant.
submitted by /u/rocko_hoppocheese
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Reddit » Electronic Circuits
2d ago
I have a pcb that runs an AC servo motor. There are two sections of PCB. One is power section and the other is the controller. The above is the power section. Just below the grip fuse and right above the chopper transformer the ic blows up. This ic recieves 350VDC from the controller pcb. I can't figure out why this IC keeps blowing up. Any hint would be appreciated.
submitted by /u/alimustafa533
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Reddit » Electronic Circuits
2d ago
Hi. First off, Id like to apologize if 1) this is the incorrect subreddit for something like this (I'm hoping that I'm in the right place), 2) if there is an obvious fix to my work here that I'm just not seeing, and 3) that my leads are all sprawled all over the place (this is my first time doin smthn like this to be honest lol), but I need help with correcting whatever is wrong. I'm doing this for school, and this is supposed to be something called a 4-bit adder/subtractor. Any assistance as to what to do, or where else to look for help, would be much appreciated!
The first image is the ..read more
Reddit » Electronic Circuits
3d ago
From the book \"Practical Electronics for inventors\" page 936.
I prototyped the design on a breadboard and it works. I use the enable pin as speed control by applying a PWM signal.
I was told by a colleague about an issue with the source of the low N-channel MOSFETs when Q5 is off, since the ground is cut off, the voltage at the source pins will float high and might cause problems for the low side MOSFETs (either conducting slightly or negative Vgs).
I wanted to confirm if this is a problem, and if there are other solutions to apply PWM without needing Q5 MOSFET, thanks a lot.
Also, if anyon ..read more
Reddit » Electronic Circuits
3d ago
submitted by /u/only1dramasetter
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Reddit » Electronic Circuits
4d ago
Hello everyone, I need help in connecting my LDR to my circuit. I have 2 motors connected in parallel and 2 batteries connected in parallel in the circuit. May I know how should I connect my LDR in my circuit so it can cut the circuit so my motors won’t move when there’s no light source?
submitted by /u/Early-Magician-9863
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Reddit » Electronic Circuits
5d ago
Hi,
Despite my EE education, I'm unsure what is the role of the current mirrors in the schematic - https://github.com/littlebitselectronics/eagle-files/blob/master/INPUT/LB_BIT_i13_LIGHTSENSOR/LB_BIT_i13_LIGHTSENSOR-v03(5_5)/LB_BIT_i13_LIGHTSENSOR-v03(5_5).pdf/LB_BIT_i13_LIGHTSENSOR-v03(5_5).pdf)
- The Op amp U1 on the left has gain = 1 and practically turning the current mirror from R4, Q1A, R3 on and off based on the Op amp input. In case of SM1.SIG = 0 V I can say the Op amp output (pin 4) is at 0V, hence current mirror is on, but the Q2 is closed.
So where the mirrored current from Q1B is ..read more