1. B

    G9 LED capsules in series

    I have a simple circuit which comprises 10 G9 LED capsules in series connected to a power source. Each capsule is made up of the following circuit: Each LED dissipates approx. 0.45W for a total power dissipation of approx. 4.5W. Total voltage drop across all the LEDs is 1619V using 2.8mA...
  2. K


    Can someone please teach me how to diagnose what's wrong with this circuit board it's for the led lights for my tail light
  3. J

    Optimizing a circuit

    Hi, Just finished doing my first proper schematic(*) and I'm worried that it's a bloated over engineered lump of components. What I'm trying to do is having 3 LEDs, powered by 2-3 AA batteries fade in and out. I've added a 4th LED which will be on when all 3 are off, I realize that could be...
  4. R

    How to power an old LED lamp via USB

    Disclaimer: I'm not an engineer, just a DIY enthusiast. So I have an cheap old plastic SMD LED desk lamp but its battery and circuit board are missing. I want to turn it into a USB powered lamp for my new apartment but I'm not sure of the best way to power it. It has 31 LEDs and the label on the...
  5. isagollo

    DC Motor in parallel with a Voice Recorder Playback Module

    I’ve build a circuit using 3V(2x 1.5Volts AA battery)connected in parallel with a ISD1820 Voice Recorder Playback Module with Speaker in parallel with a DC Motor and a Red Led. When I turn the circuit on the LED brightness reduces and the recorded audio in the speaker doesn’t play. What should I...
  6. Alois Luong 1

    Advice on wiring a LED system

    Hello! I am trying to wire up a small RGB LED system in my bedroom and would care for some advice on the best/safest/most efficient way to wire up the LED strips. I have four rolls of 5m long LED strips (see specs below) and I would like to lay them out as seen in the diagram attached (see...
  7. P

    LED status readback circuit

    Sorry for such foolish question, but what is the behaviour of circuit below: LED_ON is 3.3V logic control signal, LED_STATUS is output signal to MCU pin (GPIO). When LED_ON is logic high and Q1 is open LED1 is ON and LED_STATUS = '0', but what will happen when LED_ON = '0'? Q2 will be...
  8. F

    Cheap Xmas led light hack: how?

    hello all, I have a cheap xmas led light which I need to hack... how to hack the circuit and instead of looping the settings (blinking light types) with the button, I need the light just to stay steel. Thank you for any suggestion
  9. youtubeuni

    Convert PWM to DC 12v output for LED brake lights

    My buddy and I have been working on a project for the last 2 years, its a PCB board with 79 LEDs and built-in microcontroller taillights. We can controll every aspect of them... but we've hit a snag when it comes to power. The Volvo C30 uses PWM to send signals to the taillights. This needs to...
  10. thatguy98

    current limiter for led lights

    hi, i have 4 led lights designed to work in ac but i want to use them in a garage that doesn't have power. The lights consist of just an led strip without any resistors, have a forward voltage of 60v and draw 300mA. I thought of removing the ac/dv converter and just use a 60v battery to power...
  11. M

    Please help me with getting the values from the digital meter to raspberry pi

    I am doing a project on automating a hydroponic system to grow tomatoes. I need a TDS sensor to measure Total Dissolved salts. I searched a lot for a sensor but I was not able to find a sensor that satisfies my requirement. I need a sensor that can measure high ppm. But, the sensors are only...
  12. S

    RGB LED Strip - Red Light not working after connecting the 2nd strip with Amplifier

    Hi there! Okay so I have 2 RGB LED Strips connected with a portable RGB LED Amplifier but I cannot get the red light to work on the second strip. The Blue and Green ones do work flawlessly on the 2nd strip. Things to note: - I've used 2 power supplies (12V, 2A) - one for the first strip...
  13. F

    Power Supply + ESP8266 + LED strip : how to put everything together with a physical switch too?

    Hello, I am planning to put together a "smart LED strip" by purchasing: - ESP8266 - this one - LED Strip (%V) - this one As far as I am concern, ESP8266 has mini USB as input (5V) and 5V as output... therefore, if I use a stripe not longer that 2 meters, I should be fine with a simple USB...
  14. Elusive

    How to make a momentary switch deliver a pulse on one circuit, while also closing another circuit until it is pressed again

    It has been over a decade since I've done anything circuit related, and I found out the hard way that I have forgotten basically everything. I am trying to make a buttonpanel acting as an input interface for PC using an arduino. I want to have 32 different momentary inputs in a 4x8 matrix. My...
  15. Z

    PIC- making potentiometer match second potentiometer not working

    I'm tryng to make a DC motor into a servo motor. The motor axle has a gear that is in sync with a gear on a potentiometer (MOTORPOT in the code) and I have another potentiometer that works as an input that the motor potentiometer should match in position however I set this pot(CONTROLPOT in...
  16. G

    Two LEDs and 2 SPST. Four states?

    Hello, Newbie question I have a device that have two SPST relays that I control. From these relays, I would like to control the ON/OFF states of two LEDs (red and green) and a high/low brightness state. This gives four possibilities: Red High brightness Red Low brightness Green High brightness...
  17. O

    120v G4 counter lighting fixture. halogen to LED.

    I recently decided to switch over to LED, because these halogens use so much power and output so much heat. The fixture is not dimmable. The new LEDs are rated for 120v, 35w equivalent. I replaced all the bulbs in the fixture, turned them on and they were so dim. I turned them off but they...
  18. J

    Automotive led headlight problem

    I have a set of led headlights for my truck that won’t power up when plugged in or directly wired to car/automotive battery, yet when I use a little 23a 12v battery they do power up. I’m confused!! Why does this happen? And why won’t they work in my truck?
  19. Danirov

    Fail: Low battery indicator blink and dim

    Hi! I would be very grateful if you can help me. I have been building some circuits to turn on a LED when the battery is low (images), but there is a problem: The led dim and blink between the OFF and fully ON state for some minutes. My circuit consumes 0.23A and is supplied by a 3.7v/1400mAh...
  20. C

    Driving solid state relay input

    Can a 4-20 mA (constant VDC) analog output on an industrial controller be used as an input on a solid state relay? I wasn’t sure how a device behaving as a variable current source might interact with a load such as the LED in an solid state relay that varies in its current draw. For example...