Potentiometer not working after connected to wires

Hi, I'm fairly new to electronics and I'm trying to learn it with my Arduino. Recently I have been working on a project that involves 4 potentiometer(pot). I'm using one 1k pot and 3 10k pot. The pot is used to send signals to the analog inputs of the arduino. To test the pots I used a simple serial.println program that sends the value of the pot from 0 - 1023. When I connect the pot through its 3 pins directly to the breadboard, all of them work perfectly fine and gives me a stable value as I turn the pot. However, when I soldered three wires to them each, 2 of them work and 2 of them didnt. The 1k and one of the 10k pot didnt work. When I connected it through its wires, the values it gave kept jumping even when I'm not turning the knob and sometimes it will just stay one value when I'm turning it or not. Why is this happening? Did I overheat the pot when soldering? I took some new pots and tested them again through the pins directly and it worked perfectly fine. But when I soldered the wires to it, this time the 10k worked fine and the 1k didnt work. It gave the same problem as the ones before. Please help me with this problem. I have attached the pictures of the pots that didn't work. Please help me check if my soldering is anything wrong. I have checked online couldn't fine anyone experiencing the same problem. TQ! 

Posted by KhayhenS 2 years ago

Why is my RGB led strip giving lots of problems?

Hi,      I'm working on project with RGB LED strips with my arduino and a ATtiny84. Basically, what I plan to do is attach the strip to my display cabinet and attach the strip to an ATtiny84 microcontroller which will program the lights. Doing this I have encounter a few problems. As I haven't receive my ATtiny84 chip from the store yet, I'm testing everything on my arduino first. I first attached a normal single RGB LED to test all my programs and it works almost fine.       My first problem was when I attached 3 potentiometer(pot) to the arduino to control the intensity of each pin(red, green, blue). It did as it suppose to. When I turn the knob the brightness increase but as I'm reaching its maximum it drops back low again. So basically as I turn the knob gradually increasing, the brightness increase gradually from zero to it brightest then drops. I have attached a screenshot of this program below. I think it may be the connection between the pot and the arduino as they are quite sensitive but I'm not sure.       My second problem is when I replaced the single RGB LED with the RGB strip, MOSFETs(TIP120) and an external 12V supply it worked like before. I attached a couple of pictures of the layout below. However, when I set all the pins to low brightness the red and blue is turned off but the green led did not. The green led is dim but not completely turned off like the others. Why is this so? I'm very sure its not a defect in the strip. I hv also a attached a picture below of it.       My third problem is when I bought the three MOSFETs from the store I got one slightly different one although with the same label of TIP120. I have also attach a picture of the MOSFETS below.  The pin that is connected to this different MOSFET seems to act the opposite of its values. As in when I set that pin to low brightness it will be bright and vice versa unlike the other two. I can easily buy another one but I would like to know why this happens.       This is not really a problem but more of a question. As you can see I attached a 1k ohm resistor between the MOSFET and the arduino output to limit the draw of current. I would like to know what would you recommend the value of the resistor because I do not want to damage my chip. Is 1k enough?       My second question is I'm using a 12V 2A power adaptor as my power supply and a L7805 voltage regulator to provide a 5V power for my ATtiny84. However when I connect it I do not get a stable output and its value is around 5.3V. According to some videos I should attach a 0.1 microFarat electrolit capacitor to the input and a 22 microFarat electrolit capacitor to the output in parallel, however when I do so my output is still not stable and is around 5.8V which is too high for the chip as the max Vin for the chip is 5.5V. So what should I do?       My third and last question is my power adapter heats up when its powered but not connected to the circuit. Why is that? And my MOSFETS and voltage regulator gets hot occasionally. Should I attached a heat sink? Is this circuit possible to be left on 24/7? and how much power will it consume?       Sorry for the long post, I'm fairly new to electronics and I'm just a student  who is trying to learn electronics on my own. I have been working very hard on this project and I hope I get the best out of it. Sorry for the bad english too. Any help and comment will be much appreciated. Thank you very much!!

Asked by KhayhenS 2 years ago

potentiometer for servo motors? Answered

I am building a master slave roboarm and using 2K potentiometer. When I rorate the potentiometer knob, the motor is rorating, but a very small rotatioin potentio meter is casuing teh servo to move very fast. How do I calibrate it? Am i using the right potentio meter? which potentiometer should i use?

Asked by srikodati 1 year ago

Does anyone know of a small passive audio potentiometer? Answered

I have been looking for a small audio potentiometer, which would fit seamlessly with my headphones. I have some example pictures of something that I was thinking of. I want a simple cable which has an input headphone jack on one end (male), and the female connector on the other end so I can plug in my headphones. I have examples, but they are just too large and obtrusive. I know that there are small slide potentiometers and was wondering if it would possible to make something like this, or if there is something commercially available. If someone with circuitry knowledge would be able to advise me on how to approach this it would be much appreciated. I like the way some headphones have volume controls which have buttons, but those control the device's volume, and that size would be what I was looking for, but with a slide potentiometer. Any help is very appreciated,    Sterling

Asked by XP1 5 years ago