T&L Publications

Ok, Thanks for these, I currently have a resistor to the base of the transistor. I used a preset to actually figure out the nominal voltage to turn on the transistor and still keep the LED lit. Just to ask a stupid question (because I should know this), Vled and Iled those can only be figured out by...

Hey All: Can someone explain why a 4050 would be used? I'm building a circuit using a LM3914 to drive LEDS. What I would like to do is switch a circuit on when a particular LED is turned on. Currently, I'm using a couple of PNP transistors which is working well. But now after reading some posts, I'm...

ENZO:

Thanks for the info, I did follow right until your selection of the 4049 Inverter. Why this one and not a 4069 which is non buffered.

I have to admit, I dont know how your guys retain all this, my head is just spinning from you description and that was an easy one.

-paul

Hey All: I've been putting together a logic circuit and been doing some reading on this board and came up with what I might consider an interesting question. Mind you I dont have a CMOS cookbook so it difficult to look things up on my own. Here goes. Whats the difference between a series 4000 AND ga...

thanks Guys!

You really cleared things up for me!!!

-paul

Hi All:

I hope this will be a simple question with a simple understandable answer.

Can someone tell me the difference between an unbuffered Hex inverter and a buffered Hex inverter and why Hex?

-thanks

paul

Enzo:

Can you give me a wire diagram of your SPDT switch using 4016 IC. I came up with a couple of PNP transistors to do the job, but I do like the idea of using IC's. I figure your using 4000 series which meet my power requirements.

Thanks
-paul

Yeah: I know, I just, well, remember I said it takes me a while. You might think of it an an initial byte. No address pins high, use this binary code output! I did get it, a couple of hours later, but thanks for the explanation. The circuit is working very well, it looks as if I had programmed it in...

Hi Philba:

If you forget about "this scheme", Byte 00, does it turn off the chip or is it like "No Output"? Does anyone use it, or is it just there?

Thanks again for ALL the valuble information. I really learned alot in this excerise!

Hi Gorgon: It worked! Perfectly, All the LEDS lit in the order they were suppose to. Thanks and thanks to all that perovide some outstanding and great information. I do have one more question. How did you know that Address 0x01 is Pin0? I think even Philba knew this. You see its very imporant that y...

Colin:

I wrote the chip anyway, just in case, but I shifted your address scheme Gorgon had me start with Address 00000001, so I started there instead of 00000000. I wonder what pin is at address 00000000?

Colin, Never mind, I just ran your data through a hex to binary converter. I see what your talking about. If the reprogramming doesn't take care of it, I will make a new chip.

Colin: I'm going to try Gorgan's suggestion first, becuase to sr=crewed up the programming. It kind of makes sense if all the extra addresses are filled with values of 0xFF and associated pins (A8 - A15) the pins are kept low, who knows what would happen, but just in case can we go over your suggest...

I set adress 0x00000081 0x0000ffff to 00.

That should do it!

OK, Done! I try again tonight!