resistor

Hello all I'm trying to make a small circuit in which i have to choose the resistance value.. can someone tell me how to choose the resistor value at the input of Optocoupler IC. And my input voltage is 3.3V .. and current 25mili amps ..

Hello, looking for assistance, I am used to identifying resistors by the colour code. I have a pair without colour code, these were soldered though hole in a power supply PCB for a Bang and Olufsen television. The PCB is about 8 years old and the failure seems to be commonplace at this age...

Need help identifying this component, in the motor control board for my Sole 2014 F63 treadmill. I believe it's a fusible resistor but can't tell what size or kind. Also not sure if this is the root of the original problem (see below) or just an added headache to slow me down and get me yelled...

So I have been working on a BASH amplifier out of a Triad Silver Omnisub and have come across a resistor that I’m having a hell of a time identifying the value of. It reads at very close to 39 ohms, but from the colors of the bands on the resistor, I’m stumped as to what it’s original value...

Hello everyone. This is my first post on the forum, I am currently working on a seemingly simple circuit. I think a constant current driver is the solution; after wiring everything up last night the LED was nice and bright and circuit ran great. I decided to charge the Lipo over night, and when...

Hello, I have a broken Panasonic TV that has a broken three-pin RWT05 15 ohm 142 Celcius cement resistor. Not a ceramic capacitor. It's a cement resistor. I messed up in the title, sry about that. Now my question is, is there a replacement for it, or a resistor that I could use instead of that...

So I have a switch connected via two wires to a two pin plug which is supposed to go in a two pin socket. One pin of the socket goes to 5V and the other goes to a digital I/O in the Arduino + GND (via 10K). When the switch is pressed and the digital arduino pin goes high, stuff is supposed to...

This circuit has been designed and optimised. When implementing on PCB R3 resistor is burning up. Any reasons or suggestions for this to happen? Circuit is stable and safe when supplied with 190V and any higher R3 starts burning up. R3 has a power rating of 0.125W went with the parameters of PI.

Hi, I noticed that 4.7k ohm pull-up resistors are used in this circuit on the read/write memory pins: Saundby's MAG 85(scroll down to yellow text), but in other circuits where the read/write / io/m signals are decoded by the 74138 for example, pull-ups are not used? Is it because in the MAG 85...

Hello everyone! I'm trying to solve this assignment and I'm not sure what to do with all those resistors. Should I calculate an equivalent resistance for each group? And how do the resistors connected between the terminals of the op-amps influence the circuit?

I have a garage door and the controller board had a few dead components that i replaced, but the only one part is difficult to find bc it's dead and i cant measure it, is this a "10 kOhm 1W" resistor or a "10 Ohm 1W" or is it a really different one?.

I have watched recently this video: At the end of it he describe a way to make edge detector by using capacitor and resistor. The thing is i don't see it being discharged in any way. Would't it make it impossible to charge again and in consequence make current flow through the resistor and make...

Hi all, below is a TL 431a voltage regulator circuit. Just out of curiosity, what can I do to replace TL 431a with its internal discrete components circuit so that I can better understand how a voltage regulator works :) I have posted my LT Spice file below so that you can unzip and simulate it :)

Hi readers:), I found datasheet for HALF-BRIDGE DRIVER IC here . I was hoping to find the IC discrete components circuit from which it was built upon using transistors, diodes, resistor only but its not in the datasheet. I tried to search the web for it but it offers H-bridge with negative and...

Hi everybody, greetings from Portugal. I was wondering if somebody can help and is able to translate this “Martian R” ‍♂… you will get why ‍♂. R18 omh I think it is… (brown-grey-black-gold-black?) but what tolerance? (Black doesn't exist, as tolerance, and if you start to count from the other...

Tesla Coil Not Working. Transistor Getting Extremely Hot. See The image Below. I Did not use a switch and i did not use an led

I have some old electronic components that I got from someone who repaired TV's, radio's... I assumed these were resistors, but the measured resistance doesn't match with the color code. For the ones with the brown body (see picture), I have two of them with the color code...

TLDR: ID & ideals on mangled through-hole components, images below: Story: The Torontonian's Tale of the Fridge Fiasco Out with the old, in with the new! Or, so the non-electronics hobbyist will say when an appliance malfunctions. But, me? No, siree bob! Not with a soldering iron and all the...

Hi there, I wish to connect multiple i2c chips together on the same PCB board, these chips are DS1307, DS1621 and AT24C256. My question is, do I need to put 6 x 4.7k pull-up resistor (2 resistor / chip) or 2 x would be Ok for those three chips as shared? Also what will happen if I would...

Greeting All, I have a Welding Inverter Machine which is Model # TECHNOLOGY 238 CE/MPGE 230V . The welding workshop reported that the machine is damaged/not working and unfortunately they open and remove/lost the resistor without any knowledge. And when I open the machine I saw that the...