Can someone please show me this circuit?

Adjuster

Joined Dec 26, 2010
2,148
It's called people need to use one system. One of the schematics I looked at for my 555 used electron flow and didn't specify that while the other used conventional.
For future reference, note that schematics are normally marked with positive and negative voltage inputs in the same way, regardless of which convention may be used for labelling current flow.

It is rare to find electron flow indicated as current direction, but probably less rare for people to make mistakes in reading or writing schematics. You can never be too sure, particularly with things that come from sources whose credibility is uncertain, e.g. on the internet.

When it comes to IC pin-outs, checking against manufacturers' data sheets is a good idea, though not infallible. For a common device like the 555 it is often possible to cross-check with more than one supplier.
 

Wendy

Joined Mar 24, 2008
23,415
We're pretty consistent here on AAC as to voltages and flow. The AAC book declares early it uses electron flow. I have never used anything but in my 35+ years.

In general with chips Vcc is the + power supply, Vdd is the negative. Ground is just that, the common point. + is still plus with either system (conventional or electron). A general rule of thumb is the arrow points to the negative power supply.

Truth, I've never heard of people having problems with this on chips, but everyone learns differently.
 

thatoneguy

Joined Feb 19, 2009
6,359
You might want to order 25 from DigiKey, you'll save a lot of money. Especially if you are going to do more 555 projects, or multiples of the same one. If you are buying them from Radio Shack, you could have paid for 25 from DigiKey with shipping by now.
 

DerStrom8

Joined Feb 20, 2011
2,390
The difference between conventional flow and actual flow has to do with voltage vs. current. Conventional flow has to do with voltage potential, not the actual direction electricity is moving. In most cases, this is what is really important to us. 5 volts on a pin is +5v with respect to ground.

Actual flow has to do with current, which deals with the movement of the electrons themselves. In actual CURRENT flow, electricity moves from negative to positive. It is good to understand this in many cases, but one would not necessarily NEED to know this to build *simple* circuits.

This is how I've always understood it, anyway. I hope it will help somebody, and if any parts of it are wrong, please let me know.

Regards, and happy 2012!!! :D
 
Top