SOLVED - Resistor Confusion Over RatsNest


#1

Hi
I have created the attached circuit beginning from the Schematic View.
I got that totally to my liking and then built the breadboard version.
Then I went back to schematic and there’s now a ratsnest connection going through all my resistors. Why would this be ?
Also there’s apparently 3 other missing connections on top of the 16 resistors which I cannot even see at the moment.
Am I going mad ?
Thanks in advance
Ben
WS20 - DigitalThermometer V2.fzz (36.5 KB)


#2

Click on a pin hole on the breadboard and you will notice 5 pin holes light up, that shows they are connected. Your resistors are running across a connected row. Basically if you can’t do it on a real BB you can do it in FZ.

You also have 2 red connections in the SCH view, indicating there is no connection.


#3

Hey @Old_Grey - thanks for the response.
The diagram reflects what I have set up on the breadboard currently - are you saying that the circuit I have built should not be working ? It’s working really well so I am definitely confused somewhere here.
Thanks,
Ben


#4

The resistors should not be doing anything, like a straight through wire, unless you have a new type of BB. Pull them out of the BB and see if it works.


#5

Oh my God I am so stupid !
The power is taking the path of least resistance. I seem to have been thinking that placing a resistor along the breadboard path would somehow make the resistor the “path” rather than realising that the real “path” would lie along the row of the breadboard. Therefore, as you pointed out, I have negated the resistors totally. So my circuit works by luck rather than by design.
OK - you’ve taught me a fundamental lesson here, and I need to rebuild various things I have built previously in order to reinforce that.
Thank you so much @Old_Grey - you’ve moved my understanding forward tonight :slight_smile:
Cheers,
Ben


#6

It gets worse - I have been repeating this stupid error for the last 12 circuits I have worked on.
Thanks again


#7

Looks like the resistors have to be there for the LED display, so you will have to run the resistors horizontally to the ICs - they have bendable legs so you won’t need most of the wires -.


#8

Better yet you have discovered your error before (or at least hopefully before :slight_smile: ) something burned out because it got too much current which is the likely effect of an error like this.

Peter


#9

Yes indeed. I have spent the last two nights re-engineering my previous Fritzing diagrams to make sure I have eradicated this stupid misconception on my part. Unfortunately I have to work during the day at my real job - Grrrrr ! Hopefully by the weekend, I will be back to progression rather than repeating previous work.
Fritzing is utterly brilliant by the way - it’s given me a load of satisfaction and also a way to effectively document what I’ve been doing :grinning::smiley::smiley::smiley:
Thank you both for input @Old_Grey & @vanepp