1. K

    Clock edge detector using capacitor and resistor problem

    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...
  2. MrsssSu

    TL 431a voltage regulator circuit

    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 :)
  3. MrsssSu

    Discrete Half-bridge driver

    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...
  4. pinedo

    Help identify “a resistance.“

    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...
  5. R

    Tesla Coil Not Working. Transistor Getting Extremely Hot

    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
  6. Jorne

    Component identification - resistors? [solved]

    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...
  7. Tentmaker

    Help me ID: Unidentified Components: Capacitor, resistor/fuse (with fridge fiasco story)

    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...
  8. beic

    i2c Pull-up resistors for multiple chips

    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...
  9. Q

    Missing Resistor inside Inverter "Welding" Machine PCB - How to know the Resistor Value .. Please help ..

    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...
  10. Dan121

    Help on resistor type

    Hi I have what looks to be a blown resistor in one of our blenders. I had a look online and calculated the resistor to be 49 ohms but I am unable to find any new ones to buy. I have attached a picture in case my calculation is wrong so please feel free to correct me. If any other resistors will...
  11. TravisHC

    HELP *** Burnt resistor of camera.

    Well to start i am in no way an electrician or an engineer. Lol I'm just an old ironhead, im a ironworker and my hobby is electronics but I'm always working in the software side but as of lately I been dabling in the hardware side and got a soldering iron and everything needed with it I havnt...
  12. ConnaTC

    Resistor Detection Circuit

    Hi Guys I’m looking to build a circuit which will light an led when it detects an 420k resistor will i require a transistor circuit for this to work? If this post is in the wrong section I apologise i am a new user?
  13. G

    Li-ion cell charging module resistor selection?

    Greetings. A vendor selling TP4056-based 5 V charging modules for Li-ion cells specified the following resistance values and resulting current for selecting the current-programming resistor: R (kΩ) I (mA) 30 50 20 70 10 130 5 250 4...
  14. Gemmy101

    ATX power Supply - Broken Zener Diode

    Hey All, I have old ATX PS and I am trying to fix it and then will convert it to bench PS. after checking the PS, I found a broken Zener (or exploded) next to a broken resistor. I can guess the resistor value as it is not completely damaged, but the Zener is coming our in pieces and need your...
  15. Lambo Av

    Generator protection, calculating resistance for protection

    A 20kV, 100VA generator is protected by differential protection. 70% of the winding will be protected against the phase. What is the value of resistance to be located at the "Neutral to Ground" protection if the relay operates 30% out of the balance current? Below are my steps to the solution...
  16. T

    RGB Led problems

    Hello, Iam still pretty new to electronics this is my first time using a RGB led i plan on each color to be on at one time no mixing colors, the part iam using is a common Anode RGB I planned on using a 5v power source to connect my anode to, the max led ma each color can handle is 20ma which i...
  17. brenduan

    Arduino Motor Circuit Only Getting Less Than 1V

    Hello, I have built this motor circuit for my Arduino and when running it only gets less 1v and the motor spins very slowly and my bigger motor doesn't spin at all. I have attached the diagram that I followed below. The Motor should be getting 5v from the Arduino although something seems to be...
  18. R

    Slayer Exciter using darlington pair

    Hi guys, this is my first post here. I hope I'm in the right section. I've made a slayer exciter with a 22kohm resistor, a 2n2222 transistor, using a 9v battery. My secondary is 0.25 mm and 10 cm in lenght. My primary is 4 turns. I wanted to obtain some sparks, and I added a 47k instead of 22k...
  19. G

    How can you design a PCB for climate control as well as to turn on lights via relay?

    I’m pretty much a noob when it comes to hardware and for awhile I have been trying to figure out how to design a PCB layout. The Problem I have is trying to figure out the values for capacitors and resistors how to connect them with the other parts (like pull up resistor, bypass capacitor etc...