milennium switch 2

[cornelvis]

Alright, I'm a bit new to the forum, but I got a strange question I guess.
I built an millennium switch version 2.
Here's what happens:
I wired it up and it didn't work.
I wanted to take it off again but noticed that when I place my finger on the Ground (the one who goes to the switch) the light lids up........ 
I work like a grounding for the led to lid up.

Can someone tell me what is going on?

Did I swap pin out or something ?

Please let me know

Thanks

CornElvis

[R.G.]

In the absence of any other data, yeah, you probably got the MOSFET pinout wrong. You really have to check them, as manufacturers make all the possible pinouts in one device or another.

[cornelvis]

ah, sorry about that, I thought it might be a common thing....

I will post later on to the forum with some pic's and numbers, I'm at work now.

Thanks for the quick response.

[cornelvis]

As I used an ancient mosfet on the one I build yesterday (can't remember which  now and I'm at work...), I am willing to buy the proper fet's.

But I came across FET 2N 5457 for only €0.12 is this part possible?

let me know so I can order

Greetzzz,

CornElvis

[Mike Burgundy]

Most small-signal MOSfets should work, just make absolutely sure you get the pinout right. If in doubt, there's an easy test for the pinout with e DMM:
Put your meter on the diode setting.
make sure you don't touch the MOSfet leads with your fingers when under test (or anything conductive or static), it'll mess with the measurement. Short out all leads with your -probe. I use an isolated alligator clip to the attach the - probe to what I think is the source and provide a handhold at the same time. If you then touch the + probe to the drain, you should get a high reading - shorting out the leads turned the MOSfet "OFF".
-Now touch the + probe to what you suspect is the gate. This leaves enough charge on the gate to turn the MOSfet "ON". Now once again touch the suspected drain. If you got the pinout right, your meter should read low. You can repeat the test: turn it "OFF" by shorting the gate to the source, and "ON" by touching (charging)the gate with the + lead.
If nothing happens, , repeat the process but try another pin as drain, if that doesn't work choose another pin as your source and repeat.
If you find a low reading that does not change with charging/discharging, verify that it does not conduct in the reverse direction. If it doesn't, you've found the protection diode built into most MOSfets, between source and drain. The source is hooked up to the - side of the diode. You now know what the source is and can test as above.
If it DOES conduct both ways no matter what you do, the MOSfet is shot. Usually this is between drain and gate, or even all three.
If your measurements seem really weird, you might have a P-channel MOSfet instead of an N-channel: that works the other way 'round.
Hope that makes a bit of sense...

[R.G.]

But I came across FET 2N 5457 for only €0.12 is this part possible?

It is, but only for the Millenium 1. The Millenium 1 works with JFETs, the Millenium 2 with MOSFETs.

If you have a CD4049 or CD4069, you might want to try the Millenium C. The Mill C uses an ordinary CMOS logic chip; these chips are probably as common if not more so than MOSFETs.

[cornelvis]

Thx for all the responses.
This is the MosFet I used : S-8054HN.
I'm going to work on it today so I'll keep you posted
But should this transistor work?

[R.G.]

This is the MosFet I used : S-8054HN.
I'm going to work on it today so I'll keep you posted
But should this transistor work?

I can't relate that number to any part type I know. Do you know the original maker and can you find a datasheet for the part?

If not, assume it will not work and find one that you CAN get a datasheet on.

[boyersdad]

While we're on the topic of the millennium, I'd like to quickly share an observation.

I've made about 5 or 6 millennium 1's now on my own designed pcb (smaller than a penny), and always wondered what this talk of them latching up or staying dimly lit when inactive, or taking a few seconds to "warm up" was all about.

I made several with 2N5457, and never experienced any of these issues.

Then, I ran out of 2N5457, and used a 2N5485. It stayed very faintly lit while in bypass mode! I think it looks cool personally, so I think I'll use the 2N5485's from now on.

Also, just for giggles, I tried to add a millennium 1 to my constantly evolving Crybaby by piggybacking it to a pole on the DPDT switch.
It would turn off in bypass, but then vvveerrrrryyyyy slowly creep back up to almost full brightness, no matter what value resistor I shunted across the LED. Also kinda cool, but quite useless in this application.