Hey all. I posted this question in the general discussion area, but it may be better suited here. I'm hoping someone can help me with a small project I've been working on, but can't make progress with. I want to make a decade counter that won't turn on for 17.5 seconds. I'm interested in a design like this:
http://delabs-circuits.com/cirdir/theory/gates/doc00020.html
I've rigged 10 sets of 7-segment LED displays to show one digit each (each display will show one digit that is alsways the same - no need to encode/decode) and want to have them flash one at a time in place of the LEDs shown in the circuit: staying on for about 1/2 second each. The circuit will be powered by 5V DC and would be activated by a momentary pushbutton switch and I want the sequences to cycle over and over again until the voltage source is removed.
I contacted the designer of the above-listed circuit and he was kind enough to suggest that I try:
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"use chip CD4541 for the 17.5 Sec delay
http://www.standardics.nxp.com/products/hef/datasheet/hef4541b.pdf
http://www.fairchildsemi.com/ds/CD%2FCD4541BC.pdf
See the drive circuit here http://www.acroname.com/robotics/info/articles/drivers/drivers.html
http://terpconnect.umd.edu/~toh/ElectroSim/relay.html "
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I've purchased the CD4541 chips he mentioned, but am lost in how to hook one up to the circuit and to set the delay I need. Essentially, what I want is to use this circuit in a "geocache", where an audio recording begins and part-way through it, the sequencing of seven-segment displays give you your next set of longitude/latidude coordinates. For those who don't know what geocaching is, imagine a scavenger hunt where the goal is to find a hidden container using a handheld Global Positioning Device (more info is available at geocaching.com). Some of these geocaches have themes and this one will be related to a Boy Scout Merit Badge Series - the Electronic Merit badge. I am pretty new to the electronic scene, so what seems "obvious" to some people may not be to me, though I do have some background to work with.The person I contacted was nice enough to respond and try to help, but I don't want to keep bothering him. Does anyone want to try to help work this out?
Thanks,
Nashuan (Michael)
http://delabs-circuits.com/cirdir/theory/gates/doc00020.html
I've rigged 10 sets of 7-segment LED displays to show one digit each (each display will show one digit that is alsways the same - no need to encode/decode) and want to have them flash one at a time in place of the LEDs shown in the circuit: staying on for about 1/2 second each. The circuit will be powered by 5V DC and would be activated by a momentary pushbutton switch and I want the sequences to cycle over and over again until the voltage source is removed.
I contacted the designer of the above-listed circuit and he was kind enough to suggest that I try:
---------------------------------------
"use chip CD4541 for the 17.5 Sec delay
http://www.standardics.nxp.com/products/hef/datasheet/hef4541b.pdf
http://www.fairchildsemi.com/ds/CD%2FCD4541BC.pdf
See the drive circuit here http://www.acroname.com/robotics/info/articles/drivers/drivers.html
http://terpconnect.umd.edu/~toh/ElectroSim/relay.html "
------------------------------------------
I've purchased the CD4541 chips he mentioned, but am lost in how to hook one up to the circuit and to set the delay I need. Essentially, what I want is to use this circuit in a "geocache", where an audio recording begins and part-way through it, the sequencing of seven-segment displays give you your next set of longitude/latidude coordinates. For those who don't know what geocaching is, imagine a scavenger hunt where the goal is to find a hidden container using a handheld Global Positioning Device (more info is available at geocaching.com). Some of these geocaches have themes and this one will be related to a Boy Scout Merit Badge Series - the Electronic Merit badge. I am pretty new to the electronic scene, so what seems "obvious" to some people may not be to me, though I do have some background to work with.The person I contacted was nice enough to respond and try to help, but I don't want to keep bothering him. Does anyone want to try to help work this out?
Thanks,
Nashuan (Michael)