- #1
LurkingEyes
- 18
- 0
I'm not really new to Digital Electronics, but this is confusing the crap out of me. My school's started a DE class and at the moment we're getting all our equipment worked out and stuff, but for some reason NONE of our IC's work. We're using a 9-volt batter with a 7805 regulator for 5 volts out (measures up to about 4.2). When we connect the chips to the power, they go haywire. I'm mainly using a 7408 (Quad 2-AND) to test with, and it doesn't matter if A and B are high or low, Y is always high. It doesn't even matter if the chip is grounded, as long as VCC is high, there is an output. What gives?
We have two work-stations that have their own 5-25V power supplies in them, and they work fine. By now you've probably come to my conclusion that it's the 9 volt batteries or the 7805's. But here's the kicker, I've hooked the non-powered breadboards up to the supplies on the workstations, and it STILL has this problem. So the only other thing I see is that that breadboards are messed up...but All 20 of them??
We have two work-stations that have their own 5-25V power supplies in them, and they work fine. By now you've probably come to my conclusion that it's the 9 volt batteries or the 7805's. But here's the kicker, I've hooked the non-powered breadboards up to the supplies on the workstations, and it STILL has this problem. So the only other thing I see is that that breadboards are messed up...but All 20 of them??