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Cannot find Vcc and Gnd on eagle
- Thread starter nathomas
- Start date
StayatHomeElectronics
- Joined Sep 25, 2008
- 1,073
your welcome...
StayatHomeElectronics
- Joined Sep 25, 2008
- 1,073
Here is also a list of tips for the first pcb board...
http://www.expresspcb.com/expresspcbhtm/Tips.htm
http://www.expresspcb.com/expresspcbhtm/Tips.htm
I see you have the outputs of the unused 4001 gates connected to the inputs. You don't want to do that. Leave the unused OUTPUTS disconnected. You should connect the inputs to Vdd or GND.
You may run into Erc complaining about multiple voltage names being connected on the same node, or needing Vcc and GND for some ICs, Vcc, Vee and GND for others, and Vdd and Vss or GND for CMOS IC's. One way to get around that is to use jumpers; there are SMT/SMD jumpers as well in the jumper.lbr. If you have multiple signal names connected to a single node, you will likely have problems with routing. For example, with IC2 you have connected +12 to pin 7. I don't know offhand what library you found the OPA177S in, but you should find out what the library signal name is. Disconnecting +12 from the pin should give you clues when you run the next Erc.
Use Erc (schematic capture) early, and use it often. If you don't make Erc happy, your life will be unpleasant during routing.
If the board and schematic get out of sync with each other, life gets really miserable until they are returned to synchronization. I have had to delete a bunch of stuff to get them back in sync. It's one of those things you try to let happen only once.
I like to use the symbols in supply-2.lbr, as they are more in agreement with US standards than those in supply-1.lbr. I don't use the 0v symbol; I use GND instead, as most library parts use GND (or Vss if CMOS) for the low side supply.
Don't forget that although you have labeled (NAMEd) nodes using the labels in the supply-x.lbr's, the labels do not provide connection points to the board. You will need to hook up a connector or a wirepad to actually get a place to connect something to the trace. I see you have used connectors, so that part is covered.
You may run into Erc complaining about multiple voltage names being connected on the same node, or needing Vcc and GND for some ICs, Vcc, Vee and GND for others, and Vdd and Vss or GND for CMOS IC's. One way to get around that is to use jumpers; there are SMT/SMD jumpers as well in the jumper.lbr. If you have multiple signal names connected to a single node, you will likely have problems with routing. For example, with IC2 you have connected +12 to pin 7. I don't know offhand what library you found the OPA177S in, but you should find out what the library signal name is. Disconnecting +12 from the pin should give you clues when you run the next Erc.
Use Erc (schematic capture) early, and use it often. If you don't make Erc happy, your life will be unpleasant during routing.
If the board and schematic get out of sync with each other, life gets really miserable until they are returned to synchronization. I have had to delete a bunch of stuff to get them back in sync. It's one of those things you try to let happen only once.
I like to use the symbols in supply-2.lbr, as they are more in agreement with US standards than those in supply-1.lbr. I don't use the 0v symbol; I use GND instead, as most library parts use GND (or Vss if CMOS) for the low side supply.
Don't forget that although you have labeled (NAMEd) nodes using the labels in the supply-x.lbr's, the labels do not provide connection points to the board. You will need to hook up a connector or a wirepad to actually get a place to connect something to the trace. I see you have used connectors, so that part is covered.
