how much current can I draw from the Vin and Vdd terminals?

Raphael Linker

I want my Basic Stamp to drive a 4-bit counter (SN7493) and a 4-bit latch (SN7475). Can I use the Vdd or Vin terminal on the Board of Education to power those 2 chips?
By the way, what exactly is the difference between the Vin and Vdd terminals?

boeboy

Vin is to the unregulated voltage coming from the battery pack. Vdd is the output from the regulator on the BOE and yes you can have those chips on Vdd not Vin as it can be from 6 to 12 volts.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
lets see what this does... KA BOOM (note to self do not cross red and black)

AIman

The best thing to do is figure out what you want to do and then build the needed circuits from that using the Stamp and its power only to run stuff that monitors and controls the other items.

Here is what I mean - I can run 4 servos off my BOE without a problem - BUT - I can't run my stepper off that same power source because A) it requires to much power it needs a seperate circuit and C) other components would fail to function properly.

The short answer is to look up the specs on the Parallax web site. The reason I say that is because alot depends on what you are trying to do and what you are trying to run. If in doubt you can always email the tech guys.

Of course if there are questions about specific things posting is a good idea, but a question like you posted leaves a lot of wide open debate.

If you want a more specific answer it depends a lot on what you run for power. My stamp uses a 9 volt power supply but can run on 6 to 12. So if you figure you incoming power and tap into that you can get more power. If memory serves a stamp uses 5 volts, but it is recommened that you always use seperate power source for the stamp and components so that the Stamp doesn't brown out, depending on which stamp it could take upto 24 volts max.

Thats a long way of saying use two powers sources and the stamp takes at least 5 volts.