555 Timer Police Lights Issue

MrChips

Joined Oct 2, 2009
30,808
You have two short orange jumpers in the middle of the power rails.
On some breadboards these are required. I don't thing you need these for this board but it makes no difference.

I cannot see clearly the power connection to pin-4 of the 555.
It looks like the red wire is connected to pin-3.
(The first photo you posted has it correctly going to pin-4).

btw, don't use RED for both VCC and GND. Change GND to black, brown or green.
 

elec_mech

Joined Nov 12, 2008
1,500
There are several things that need correction. I only had time to really look at the 555.

555
1. Pin 2 needs to be connected to pin 6
2. R2 should be 22k not 47k (if you're following the schematic)
3. Pin 3 should NOT be connected to pin 8 (+9VDC)
4. Pin 4 should be connected to +9VDC

I think there may be some incorrect connections at the transistors and LEDs, but I need a better picture showing how they are connected. Look especially at the yellow wire connecting the two leftmost LEDs - this appears to conenct them in series not parallel as the schematic shows.

Hope this helps.​
 

Thread Starter

(OCP)RoboCop

Joined Oct 27, 2012
8
I am starting to think I picked a project that is over my head at the moment for the first breadboard attempt, I am going to have to start over with a easier project lol
 

elec_mech

Joined Nov 12, 2008
1,500
I am starting to think I picked a project that is over my head at the moment for the first breadboard attempt, I am going to have to start over with a easier project lol
You can do this. I suggest making this circuit in two parts - first make the 555 circuit and connect a single LED with a current-limiting resistor in series to pin 3. The LED will blink when you have the 555 circuit assembled correctly. Next, build just the 4017 circuit and connect a momentary push button between the clock input and +V. Pushing the button will simulate a clock signal so you can verify it is working correctly.

Once each circuit is tested and working, connect the two together. You are close, you just need to look hard at the schematic and verify the connections to the pins are correct. As someone suggested earlier, print your circuit and use a highlighter to highlight each connection as you make it. I do this all the time and it works great.
 
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