police lights with 555 timer

[reemsoliiman]

ISIS Release 8.11.00 (Build 30052) (C) Labcenter Electronics 1990- 2020.
Compiling design 'C:\Users\clinic\Documents\New Project.pdsprj'.
Netlist compilation completed OK.
Netlist linking completed OK.
Partition analysis completed OK.
Simulating partition [049C24E5]
PROSPICE 8.08.00 (Build 29194) (C) Labcenter Electronics 1993-2020.
Loaded netlist 'C:\Users\clinic\AppData\Local\Temp\LISA5628.SDF' for design 'New Project.pdsprj'
Logic contention(s) detected on net #00007.
Logic contention(s) detected on net #00010.
[SPICE] Gmin step [22 of 120] failed: GMIN=2.23872e-005
[SPICE] Gmin stepping failed
[SPICE] Source step [0 of 120] failed: source factor = 0.0000
[SPICE] Too many iterations without convergence.
Simulation failed to start.
Simulation FAILED due to fatal simulator errors.





how can i fix it please?

 

[AnalogKid]

Without getting into the sim software, the schematic needs work.

You need to add six small signal diodes (1N914, 1N4148, etc.) between the 4017 outputs and R3 and R5, one for each output. As you have it, High and low outputs are connected together, and the poor little 4017 is trying to short out the system power supply.

R3 and R5 are too small. A standard CD4017 output stage is rated for around 2.6 mA. with a 9 V source, the high output voltage will be around 8 V. With a Q2 Vbe of around 0.6 V, and another 0.6 V across the recently-added diodes, that puts around 6.8 V across the base current limiting resistor. To limit the current to 2.6 mA, the resistor value must me no lower than 2.6K. The next higher standard value is 2.7K.

Separate from that, consider this: Because the system voltage is more than twice the forward voltage of an LED, you can put D1 and D2 in series, and D3 and D4 in series, and eliminate R8 and R10 (?). For the same 15 mA LED current, R7 and R9 will have to be reduced in value.

 

[reemsoliiman]

thank you the error has gone
but now it does not do the task required
i want the lights to flash

 

[73's de Edd]

I see that YOU /and/ SCHEMATIC CAPTURE know that and confirm that pin 1 is its ground on the 555 and that pin 8 is its power.
But, by reading both of the above schematic layouts do YOU /and/ SCHEMATIC CAPTURE AUTOMATICALLY know that pin 8 is ground - and that pin 16 is its power input pin on a 4017 . It's not being shown.
Then if you still have any quirky problems you put an electrolytic filter capacitor across the battery supply line and a .1 ufd HF bypass cap across
the 555 pins 1 & 8 vewy close . . .CLOSE . . .CLOSE . . . .to those IC pins and use the same procedure at the 4017 power pins.

 

[Neal]

thank you the error has gone
but now it does not do the task required
i want the lights to flash View attachment 57364

Q1 & Q2 and Q 3 & Q4 should not be tied together on 4017

 

[reemsoliiman]

I see that YOU /and/ SCHEMATIC CAPTURE know that and confirm that pin 1 is its ground on the 555 and that pin 8 is its power.
But, by reading both of the above schematic layouts do YOU /and/ SCHEMATIC CAPTURE AUTOMATICALLY know that pin 8 is ground - and that pin 16 is its power input pin on a 4017 . It's not being shown.
Then if you still have any quirky problems you put an electrolytic filter capacitor across the battery supply line and a .1 ufd HF bypass cap across
the 555 pins 1 & 8 vewy close . . .CLOSE . . .CLOSE . . . .to those IC pins and use the same procedure at the 4017 power pins.

Thank you for your efforts i really appreciate it
But sorry i Don't understand what to do exactly, english is not my first language

 

[davenn]

Q1 & Q2 and Q 3 & Q4 should not be tied together on 4017

they are not

 

[73's de Edd]

As a MINIMAL fact / statement . . . . .
Your schematic does not show the 4017 having its pin 8 connected to ground and it's pin 16 connected to power.

Separate observation . . . uf der " Nealster " is is confirmed below . . . . . but may not be critical, since they are overlapping and holding a HIGH state.
But Dr Analogs prescribed isolating / steering diodes definitely were needed.

 

[reemsoliiman]

Because the two pins are not showing in the 4017 on proteus, i can't see them so i can't connect them with anything

 

[bertus]

Hello,

There is also an error at the 555:

Bertus

 

[bertus]

Hello,

Wendy made a comparable circuit on AllAboutCircuits:

LEDs, 555s, Flashers, and Light Chasers

LEDs, 555s, Flashers, and Light Chasers One of the most common requests at All About Circuits is various methods of flashing LEDs. I'll try to show most of the techniques used for this purpose that have been covered on this site, explaining how and why along the way...

forum.allaboutcircuits.com

Bertus

 

[AnalogKid]

As a MINIMAL fact / statement . . . . .
Your schematic does not show the 4017 having its pin 8 connected to ground and it's pin 16 connected to power.

Separate observation . . . uf der " Nealster " is is confirmed below . . . . . but may not be critical, since they are overlapping and holding a HIGH state.
But Dr Analogs prescribed isolating / steering diodes definitely were needed.
View attachment 57366

There are no connection dots, so those might be drafting errors. You probably can drag the vertical segments one grid square to the right to see that Q1 and Q3 are not connected to anything.

ak

 

[AnalogKid]

AND, that is an excellent example of why consistent use of connection dots is *critical* in a schematic.

ak