1. 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...
  2. M

    Amplitude modulation with MCU and NE 555

    Hi, I want to build an IR transmitter (~ 38kHz). My plan is to use a NE555 timer to generate the carrier wave (A-stable Operation), modulate it with a micro controller, and transmit modulated signal via IR LED. My question: Can I connect the micro controller output pin directly to the CONT...
  3. Mariachi


    Hi! Can you help me please? I don't understand why the circuit doesn't work, but it works when the output of timer 555 is also connected to the oscilloscope, although it's the same thing.
  4. S

    Turn 6V motor on/off via 555 timer astable circuit and 5V relay

    I have been working on a circuit to turn a motor on for several seconds, and then off for a longer period, using a 555 astable circuit. The on time needs to be around 5-10 seconds, and the off time needs to be about a minute. To get around the 50% duty cycle issue and allow for a longer off...
  5. Mariachi

    PWM using 555

    I want to make a pwm generator with variable frequency. I notice that the capacitor is charged through R1, but the discharge? I don't know with what formula the duty cycle can be calculated in this case. Thanks!
  6. hopalele74

    Is this a good way to dim a 5-inch LCD for my Raspberry Pi?

    Hi. I'm trying to make a DPI display to work with my Raspberry Pi. First, I searched around and found out that the 555 timer IC is a good way to control the brightness of the display. And since the background LEDs needs around 23V to function, I've included a step up converter. It's for a LCD...
  7. Genosphere

    Trouble: Simulator expectations vs constructed circuit; 555timer.

    So I am having some trouble building the circuit I had built in a sim, several to be exact, which all seemed to work the way I wanted them to. Now that I have built the circuit on a board, Im not getting the results expected. Checked wiring and and parts, things look ok. Odds are I have missed...
  8. L

    US blinkers circuit

    Hi all, I would like to make a circuit that turns on my two front blinkers on my car permanently, and when the blinker is activated, the lamp should blink as normally. I have no experience in circuit designing, but i was thinking that maybe it's possible to use a transistor, mosfet or maybe a...
  9. zeus8Olympus

    Ultrasonic Rangefinder using Analog Components

    Hey, I'm new to electronics, and for one of my projects, I'm supposed to design an Ultrasonic Rangefinder using Analog components only! The components include the 555 timers, SN74HC chips (specifically the 4 bit counter), 7 segment display and etc. Most of the guides I have found online use an...
  10. D. All About Circuits

    Problem with high and low of 555 astable timer

    Hello. I just wanted to give a brief introduction of the type and purpose of my circuit. The circuit is designed to turn on (go high) for a time determined by 0.693R1C1 and do this (go low) periodically after a time determined by 0.693R2C2. I got this operational by using two diodes D1 and D2 on...
  11. Bbrandonparran

    Ne555p problems. Inexperienced. Help..

    Okay, so recently got into breadboards and learning about electrical engineering and computers. And by recently I mean 3 days ago. I have an ne555p chip. I am trying to make an astable clock signa for my projects. lI have no way of showing a diagram. R1-2k R2-100k c1 10uf c2 10uf(across +...
  12. Gilsdank

    How to introduce 90 degree phase shift to 555 timer?

    hello, I need to generate 2 signals: a square wave of a pretty low frequency, say 10hz. Right now I'm using a 555 timer to generate the square wave. I also need another square wave 90 degrees out of phase. How can I do this? I've attached a picture of the signals I need. Thank you in advance.
  13. P

    Charge pump "Voltage Quadrupler"- data sheet error?

    I was just checking a data sheet for the MIC1555 (an IC similar to the NE555 timer), and came across the following circuit: I confess I find following such switching circuits a bit mind mending, but as far as I can see, surely this is at best about a voltage doubler: As the output on pin 5 only...
  14. S

    Attempting to design an automated car shade, need help with the circuitry.

    Hello! I am trying to design a car shade (the thing you put up in your windshield to block the sun) that is automatic with the press of a button. I have an idea of how it will work and the design, but I am struggling with the circuit. Here is some background: The automatic shade will be rolled...
  15. À

    555 ic reference problem

    I recently purchased a new 555 ic to generate digital clock pulse it work with +5v reference but not work with common ground reference. If you know whats going wrong please let me know.
  16. M

    Monostable 555 Timer Application Question

    I'm pretty inexperienced when it comes to electronics and circuits so bear with any stupid questions I may have. I'm working on a simple DIY project. It is essentially just a box and the high level idea is that when the box is closed, a circuit is completed where it then automatically executes...
  17. Zack Maness

    Need help designing a power saving circuit for two strings of mixed LEDs. (I don't have a lot of experience designing circuits)

    I made a few Lichtenberg figures and I want to mount them in shadow boxes. I built some LEDs into the box (Three UV along the top and one red on the left under the blue tape) and I am planning on pouring about an inch of epoxy to cover the LEDs and disperse their light. For a power supply, I am...