Hello everyone, I'm working on a small hobby since its been a while since High School and remember going on here long time ago for help and ideas I thought I come back for another project .
I would like to have 9 LED's on my circuit board and have one of those LED's constantly on until I push a button for the next LED to light up in sequence. When it gets to the 9th LED it will go back to the first one when the Push Button is pressed again. I'm not sure if I'm explaining this correctly so I will attach a picture to make it a bit more clear for you. How would I be able to accomplish this project?
Use a 555 one shot, to feed a pulse to a counter chip (take your pick) something like a 7490, and then feed that to a BCD to decimal decoder like the 7442.
yes the 7495 is indeed a shift register... either the LSB output or the MSB output can be fedback to the serial input line to convert it to a ring counter
The circuit below should work. You'll need a 4017 with Schmitt trigger clock input. TI and NXP (Philips) both make these.
If you have to wait too long before being able to advance the sequence, try making C1 or R2 a lower value.
Although I selected the value of R3 to allow about 10mA (more or less depending on LED fwd voltage), my intent was to allow higher currents by changing the value.
In the "push to advance" LED circuit like in Ron's post #9, each LED stays ON until the next one is lit with another push of the momentary swtich, as the OP asked for. Besides connecting a 555 as a monostable to each emitter of the outputs, is there another simpler way to make the different LEDs lite up for just a brief moment, say 0.1 second?
Well, the microcontroller route is the next part of my electronics learning curve, and it seems that most things can now be done simpler with a microcontroller...but the question was really given the circuit as attached by Ron in post # 9, is there another way to make the LEDs light for just a brief pulse as opposed to staying on until the next press of the input switch. This is not a school project, but indeed a hobby for fun and learning.
I think you are saying to put an electrolytic capacitor instead of the currently shown 620 ohm resistor, but I am not exactly sure where the diode is connected into each output, and then how it can discharge the capacitor. Will a separate capacitor be needed for each output instead of the currectly shown common dropper resistor?