Thread: Help needed, again.

Good day all. I need help in editing one of my circuits a little bit. So, I guess this would be the time to give the details. But I'm first gonna apologize for the wall-of-words. For some reason my phone doesn't want to upload posts in paragraph form. Blackberry, go figure. Anyways, details. I've built a circuit that flashes LED's. Well, four circuits. Three of which controls a set of LED's separately, and one that controls all sets together. They are all connected to a dip-switch for on/off control. Power is in the form of a computer PSU molex connector. Just the 12V supply. Now, this setup works. It works well. But I want to improve it a little. Here is what I would like to do. I would like to remove the dip-switch selector, and exchange it for a micro-switch. I also want it to be able to switch the LED's in a pattern. Example - first push of the switch activates the first circuit, the next push activates the next circuit and de-activates the first, the third push of the switch should activate circuit one and two together and so on until all circuits are activated. The last push should be power off. I've searched for possible circuits for this and even asked a few of my colleagues at work, but all I can get is a way to activate the circuits one by one and then off. Obviously, this is not what I want. If anybody has some hints or tips, it would be greatly appreciated. Also, I believe that a timer chip will be needed. I have 556 dual timers at my disposal. I don't have the 555. Thanks in advance.

So, at least I'm not the only one stumped by this. . If any extra info is needed, please say so. Thanks.

If you have a way of operating switch contacts in sequence, then it seems you could have a particular switch contact connect to any LED circuit or group of circuits through diodes. The diodes would prevent energizing more than one set of LEDs except through the desired switch contact.

Sounds like you want to build a 4-bit binary counter, where the microswitch sequences between the numbers:

0000 - off
0001
0010
0011
...
1110
1111
0000

Am I correct?

If so, there are op-amps which do precisely this. Their counter sequences every time the input is energized, but not when it's de-energized. They're available in both 4-bit and 8-bit versions. I suggest you use a momentary depression switch, which closes when you depress it, and opens when you release the button. It looks like a standard 16-pin IC, and some of the other pins may do other things, but all you'd to connect are the ground, the power, the outputs to your LED power circuits, and the input from your momentary depression switch or microswitch.

Are you wanting to count how many times your hamster crosses from one cage to the next? :0

Originally Posted by WaterWalker

I would like to remove the dip-switch selector, and exchange it for a micro-switch. I also want it to be able to switch the LED's in a pattern. Example - first push of the switch activates the first circuit, the next push activates the next circuit and de-activates the first, the third push of the switch should activate circuit one and two together and so on until all circuits are activated. The last push should be power off.

Use a 74ls161. It's a binary counter. Connect the LED's to ports A B C D (with resistors to +5V) and connect your microswitch to the clock input. (Switch connects to ground, have a 1K pullup to 5V.) Every time you push the button you'll get a change in the LED's. After 16 presses they will all turn off.

Originally Posted by Delta Flyer

Sounds like you want to build a 4-bit binary counter, where the microswitch sequences between the numbers:


Are you wanting to count how many times your hamster crosses from one cage to the next? :0

*laughing*