Thread: LED Circuit mind of its own

Hi,

that kind of behaviour might have many reasons, such as stray AC causing a timer circuit to be triggered or a false count pulse with the same effect.

It would be helpful if you post an entire schematic diagram of the master and remote panels.

Also distance between boxes and the kind of cable used has influence on the proper function of the circuit.

Boncuk

If you use only the CMOS and the 555 you mentioned, it would be good to have more than 5v supply, 9 or 12 would be better for the I2R loses. Also, a question. Have you add a pull up resistor?

post a schematic so that we can see what you have built...we wont b scared of it!!!...also are u edge triggering yr 555?if u have a pushbutton connected so you ground pin 2 -as u release yr pushbutton u will have switch bounce which will cause unpredictable results regarding triggering and how long are the leads that connect the trigger signals to each 555?too long a lead length if its picking up electrical noise will also cause false triggering.... ive uploaded a switch debounce circuit for edge triggering yr 555 ........

2 things with yr circuit-there is no power on reset....and the 555 needs to be edge triggered as my previous schematic shows with switch debounce......heres a revised 4017 schematic...also make sure there is adequate decoupling across supply lines and on the 555 timer add a 0.1mf from pin 5 to pin 1..........

Originally Posted by sheldonstv

2 things with yr circuit-there is no power on reset....and the 555 needs to be edge triggered as my previous schematic shows with switch debounce......heres a revised 4017 schematic...also make sure there is adequate decoupling across supply lines and on the 555 timer add a 0.1mf from pin 5 to pin 1..........

The 555 doesn't need debouncing to trigger with a switch has shown.

Originally Posted by kenwalus

I will try to upload a schematic GIF format.
The boxes are connected with CAT 5 cable to the main Junction Box. The furthest box is @100 ft away

Attachment 30960

I see three problems with your posted circuit.
1. Pin 4 of the 555 needs to be connected to pin 8
2. You need on resistor about 680Ω between the common LED line and ground.
3. You need a decoupling capacitor between +9V and ground, preferably close to the 555.

regarding switch debounce-if the timed period is quite short the switch bounce will cause the 555 to retrigger and the 4017 will recieve more than the 1 desired clock pulse....switch bounce doesnt need to be a problem and there isnt much xtra circuitry to prevent it...also if he has long leads from his console to each circuit,a good clean switching signal is needed i have used 555s for quite a lot of things and switch bounce can cause strange things to happen with a 555.....

no schematic????

The ordinary 555 causes a 400mA supply current spike when its output changes state. Then the CD4017 counters get all confused when their supply voltage suddenly drops when they are clocked.
Use a Cmos 555 (LMC555, TLC555 or ICM7555) which does not have such a high current spike.