L T spice

Status
Not open for further replies.
I think the simulation program is stupid.
When the output of the 555 goes low then the upper LED should light.
When the output of the 555 goes high then the lower LED should light.
The simulation also shows an output voltage that is too high when the output of the 555 is high.
 
I will enlarge and straighen out

but regardless the led connected to Vcc to pin 3 should show a high when the 555 output goes low.
the led connected to pin 3 to led to ground shows a high when the 555 goes high.
 
Dang it now it works??

All I did was straighen out the schematic
 

Attachments

  • 2ledaltcircuit.PNG
    24.1 KB · Views: 140
  • 2ledalt traces.PNG
    32.9 KB · Views: 149
All I did was straighen out the schematic
Could this be why?
The schematic is poorly sized with tiny parts and miles of wires between them so it is hard to see what is connected and what is not connected.
To which you replied:
I will enlarge and straighen out but regardless the led connected to Vcc to pin 3 should show a high when the 555 output goes low.The led connected to pin 3 to led to ground shows a high when the 555 goes high.
It points out the value of careful drawing. Not only does a bad drawing make it difficult to spot your own errors, but most people don't even try to read bad diagrams so getting help is difficult.
but regardless the led connected to Vcc to pin 3 should
Hopefully you now understand that LTSpice cannot correct your errors, even if your diagram is too messy for you to find them..
 
Last edited:
Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…