? on CD4027BE

The op should post a schematic, would be interesting to see that.

He's going to copyright it first... bwahahahahahahaha ha ;-)

...Jim Thompson

The NPN has 3 legs and the PNP has 3 legs so he has pins left over.

Gee, Jim. The 4051/49052/4053 series are designed to use a -5 in the analog section. Since you didn't state LOGIC ONLY, I would say yes, people have. Microdyne used them in the first run of the 'Distribution Board' (Embedded controller to radio interface) in several product lines, but quickly changed to a MAxim IC that was more reliable. The Motorola 4051 didn't like a negative voltage on the input, but behaved if the input was AC. They would go into lock up, yet allow you to select another channel. Since the design used precision dividers at each input, it didn't keep the radio from working, but the radio would report a system failure. The Maxim IC didn't lock up on us, in any of dozens of designs.

FWIW, if you wrote it, you already own the copyright - all you have to do is announce it: Copyright © 2008 Dave or something very much like that.

So, post the schematic - if the design is broken nobody will want to steal it anyway. ;-)

Good Luck! Rich

. I was always taught that 4000-series logic was current limited at the outputs and could withstand a direct short to ground. Is that not right?

Jim

The instantaneous current is limited to a safe value, but if the supply is above about 12 volts, the die hot spot may reach a damaging temperature, eventually.

Yes, I understand that ownership of copyright is automatic for any finished pieced of work, I am just afraid of giving someone ideas like I got from an old PE article that was full of mistakes and missing info, which I worked to correct and supply, and am hoping to profit from (with a little actual work on my part.). I just don't want someone else to finish what I have started before I do and beat me to the punchline. And I am sure there are many who could do in an evening what would take me months. And more than a few of those here, in this NG. :) I will probably eventually post it, it will just not be right away (if anyone cares.)

Thanks for the interest,

Dave

Short circuit of a single output for a short duration, okay, but not continously, particularly if the Vdd >> 5VDC. Heating and/or metal migration over the long term.

Typical Pd with four outputs shorted to Vdd/GND and driving to the opposite is almost 2W with Vdd = 15V, which will obviously kill a SO packaged unit, and probably a DIP pretty fast.

Best regards, Spehro Pefhany

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That is fear a lot of designers have. What most don't realise is that no one actually cares and would not be bothered "stealing" a design or idea and "beat you to the punchline" for some (most likely) niche product that most likely will not interest most other designers. There are exceptions of course, but they are pretty rare.

Good designers have plenty of ideas they could turn into marketable products if they really wanted to, they don't need your circuit or idea.

So nothing to fear if you want to post your circuit. But of course, if there is nothing to gain on your part by posting it then best that you don't.

When it comes to "protecting" your design, it's usually best not to even try. Simply stay in front of any competition by being first, having the best value product, offering the best service, and upgrading the design if needed to stay ahead of the game.

Good luck.

Dave.

Um, it doesn't have anything to do with water as a fuel for an internal combustion engine, does it?

{;-)

Jim

-- "It is the mark of an educated mind to be able to entertain a thought without accepting it." --Aristotle

LOL. No sorry. Nothing so exotic...

Still grinning.

Dave

Everyone knows you can do that with a couple of 555's.

But if you could do it with CD4027's, that might just be novel enough to be patentable! :->

Dave.

Good Grief! I just now looked up the 4027 and GEEZ! Who the heck designs with J-K flip-flops any more??

Thanks, Rich

From the explanation point and multiple question marks, I am assuming that you are excluding yourself from that elite group.

Me.

Jim

-- "It is the mark of an educated mind to be able to entertain a thought without accepting it." --Aristotle

Naaaaah - I've just never been able to figure out how or why you'd use one, when a D can do anything I could think of.

It won't be necessary to post examples, I'm sure there are plenty of examples on the www. :-)

Cheers! Rich