Milenium Bypass Questions

[rasco22862]

Searching everywhere for a 3pdt switch, i finally know that it´s possible make a true by pass with a  DPDT. So i´ve read the geofx long article about the milenium bypass...and i din´t get it . I just want to make a true bypass with the DPDT. There are so many drawings about milenium bypass, that i get confused: Here is what if found:

http://www.geofex.com/Article_Folders/Millenium/millen.htm --->Long Article
http://www.geofex.com/FX_images/milltbbx.gif
http://www.geofex.com/Article_Folders/Millenium/mill2.jpg
http://www.geofex.com/Article_Folders/Millenium/milckt.gif
http://www.geofex.com/Article_Folders/Millenium/mill2bd.gif

So.. which one should i do? what´s the diference between Milenium 1 and 2? Where should i take the reference?

Thanks.

[R.G.]

The question to ask yourself is "what is the cheapest and easiest thing for me to get?" of the following:

• low Vgsoff JFETs like the 2N5485, 2SK30A, 2N5292, J201, etc.
• small signal, TO-92 MOSFETs like the BS170, 2N7000, many others
• CMOS logic packages like the CD4069, CD4049, etc.

If it's easiest for you to get JFETs, do the Millenium 1.
If it's easiest for you to get MOSFETs, do the Millenium 2.
If it's easiest for you to get CMOS inverters, do the Millenium C.

All of the Millenium circuits are a sensitive detector of DC resistance to ground. That is, they detect the difference between several inches of air (an open circuit) and a 1M resistance. The 1M resistance causes the circuit to turn an LED off. The open circuit causes the circuit to turn the LED on.

You can make a Millenium circuit entirely separate from the rest of the circuit. Just build up whichever Millenium you want, then test it. Apply +9V and ground, and test it by connecting/disconnecting a 1M resistor to ground to the control line. The LED should turn on and off. When you get this behavior, you're ready to apply it to a real circuit.

The DPDT bypass circuit is wired so that the output of the effect, which is disconnected from the signal line during bypass, is connected to the Millenium control line during bypass. The pulldown or other DC resistance on the effect output pulls the Millenium control line to ground and turns the LED off.

The difference between the Millenium 1, 2, and C are purely which device (JFET, MOSFET, or CMOS) does the reading of the control line. Otherwise, they're all the same.

[Laus]

thanx!
just what  I needed today.

[rasco22862]

In the chematic for the milennium 1, i see 2 resistors, one for 1k, and the other for 4.7k. But in the layout there is only one resistors. Where is the other?

http://www.geofex.com/Article_Folders/Millenium/milckt.gif --->Schematic
http://www.geofex.com/Article_Folders/Millenium/milckt2.gif ---->Layout
http://www.geofex.com/FX_images/milltbbx.gif ---->In this one, the diode and the two resistors are missing.

What is right layout and schematic?
Examples for silicon diode?

[R.G.]

Those are all Millenium 1's, with the JFET.

JFETs have the curious property that they will never pass more than a certain amount of current, which is called Idss on the datasheet. This happens to be about the right amount of current for many LEDs, even if it's loosely specified. The 1K and 4.7K resistors are there to make the circuit more "polite". It works in most cases without them.

Many JFETs need some series resistance to control the amount of LED current, and in some cases to get them to shut more fully off. The 4.7K parallel resistor corrects a problem with some JFETs where they will not turn the LED off, but leave it slightly glowing. And some JFETs work without either resistor. JFETs are highly variable.

The Millenium 2 and C correct this problem by using MOSFETs to read the control line resistance, and by pulling the LED down to ground, not up like the JFETs do. Millenium 2 and C have no "dim glow" problem as caused by JFET imperfections.

So - what is right layout and schematic? They all are, depending on the JFET.

Examples for silicon diode? It's better to use a high leakage silicon diode like the 1N914 and 1N4148 for the leakage diode that connects to the gate of the FET.

[rasco22862]

Thank you very much for your answers..

OK...Now, i´m nuts. If it wasn´t enough with Milennium 1 and 2, and plus, and modified, etc, now appeared a C one. .

I can´t stop finding variations of the schematics and the layouts of the Milennium 1 and 2.

Please,  , im begging you...Can you give me a right and unique schematic and layout for Milennium 1,2 and C.?

Thanks!

[Gilles C]

I don't want to take R.G,'s place, but just in case he's busy right now...

It's detailed here:

http://www.geofex.com/Article_Folders/Millenium/millen.htm

This is the layout I would use:

http://www.geofex.com/Article_Folders/Millenium/mill2bd.gif

The C is explained here:

http://www.geofex.com/Article_Folders/Millenium/The%20Next%20Millenium.pdf

But no layout seems to be available for the IC version for now.

I use the Millenium 2 with a Mosfet when I need it.

Gilles

[rasco22862]

For example in the file The Next Milennium.pdf, the layout for the  Milennium2, has another transistor. So. i´m confused again.
And what is an example of low leakage diode?

[R.G.]

For example in the file The Next Milennium.pdf, the layout for the  Milennium2, has another transistor. So. i´m confused again. i
And what is an example of low leakage diode?

The extra transistor IS the low leakage diode. I'm using the extra transistor with its emitter lead open for just the collector-base diode junction. All normal transistors are made to have that diode junction with as low a leakage as possible.

The low leakage diode is there only as a protection device for some special cases where the static sensitive gate of the MOSFET in the Millenium 2 could be damaged. The circuit works in most cases without it.

[GibsonGM]

Does the 4049 have to be UNBUFFERED?  I have a HEF4049BP lying around, don't think it's buffered, and would like to try the C version with it....