ARICLE BY JOE MISIOLEK OF THE TVQ GROUP, POSTED TO KEELYNET 8/13/93 Keelynet message 1652, 1653 ------------------------------------------------------------------ This device is a variant of the non-linear junction type detectors. It has a few suprises that you will (hopefully) discover when you build it. ------------------------------------------------------------------ ---------- PARTS LIST ---------- 1 Opto-isolator IC (NEC PS2501-4) 16 pin dip isolation voltage 5000 current transfer ratio 80%-600% Bvceo=80 minimum Ton = 3 uSec Toff= 5 uSec 1 16 pin DIP socket 1 Battery Powered variable DC power supply (regulated) 1 Oscilloscope 1 Circuit Board 1 metal box (suitable for housing RF circuits 2 RCA phono jacks (shielded) 2 RCA phono plugs (shielded) misc. coax cable, solder, etc. Construction: Put the whole thing into the shielded box. There should be no gaps where the box halves join or anywhere else that vector EM signals might leak through to the detector. It must be completely shielded from all vector EM radiation. Connect the IC to RCA type jacks using short pieces of coax. Follow the connection scheme below. Use good construction practices (short leads, well shielded and good solder connections are a must.) Plug coax into the jacks and run the cables out to the power supply and scope as shown. Theory of Operation: As you may well know, non-linear mediums will translate scalar EM. This can be exploited in most semi-conductors due to the highly non-linear junction region present where N and P type materials interface. We havethree such junctions in this detector. One junction in the LED and two in the phototransistor. WHen the LED is biased just enough to put it into 'starvation mode,' electrons begin their quantum tunneling across the junction. Scalar wavefronts passing through the junction translate into vector EM which couples with the tunneling electrons altering their spin and kinetic energy content. When the electrons find suitable quantum wells in the P type material they 'fall in' radiating their excess energy in the process. The photons emitted contain the scalar information which coupled to the electron during the tunneling process. This information is carried by the photo to the base of the photo- transistor where it is converted into a vector EM signal and sent to the scope for analysis. Enterprising researchers may want to amplify the signal before sending it to the scope. This is up to you. If you do decide to try this, use high-impedance JFET input op-amps for the task. ------------------------------------- < ASCII SCHEMATIC MISSING > Operation: Start with the power supply at zero volts dc and the scope sweep rate somewhere around 10KHZ/cm on the scale. Set scope sensitivity to highest range (.01 v/cm or better.) Slowly begin raising the DC bias to the LED keeping careful watch on the scope. At the point where the LED just starts to conduct (starvation mode) you will begin to see signals on the scope. Adjust dc bias until you get the best detection Adjust the scope sweep rate until you see the most signal detail. Observations: 1. You will note that the signals are not vector EM for they cannot penetrate the shielded box to interact with your detector. 2. They are not the result of a ground loop because you are running from batteries. 3. They are not from the battery supply because there is 5000 volts of isolation between the emitter and detector portion of the IC. Here is the BIG TEST...... This device will operate for approximately 10 minutes before failing. You will notice however that the IC will still function as an opto- isolator when placed into a conventional circuit. It simply won't detect anymore. Anyone here who can adequately describe in a private letter to me why this is so will be given the next detector plans which are quite a bit more advanced. Good luck to all! Joseph J. Misiolek ---------------------------------------------------------------------------- BILL BEATY'S NOTES I built and played with this circuit. It works. Don't bother with the extreme shielding measures, I suspect they are only used to prove that the noise is not from an external source. Yet all circuits exhibit thermal noise, so a noisy nonlinear device is not unexpected. The weird thing is the sudden cessation of the noise. If you run the LED at extreme low current and pipe the output of the phototransistor into an audio amp, when you first turn the LED on (tens of microamps) you will hear white noise. After awhile it will vanish, and you cannot bring it back. If you disconnect the circuit for a half an hour, the noise will not return. If you freeze it with cooling spray, it will not return. But if you wait for hours (overnight,) the noise source will "refill" itself again. Also, the harder you drive the LED, the faster the noise will vanish. Robert Shannon tells me that if a whitenoise source is used to drive a bifilar coil and the optoisolator is inserted, when the chip is placed back into the circuit the "noise source" will have been "refilled" again without waiting hours for it to "refill" naturally. I've not tried this experiment yet. If it works, it implies amazing things. Perhaps the disappearing-noise effect from this optoisolator circuit can be used to receive the unshieldable scalar radiation emitted from bifilar coils. Subspace morse code transmitter anyone? .....................uuuu / oo \ uuuu........,............................. William Beaty voice:206-762-3818 bbs:206-789-0775 cserv:71241,3623 EE/Programmer/Science exhibit designer http://amasci.com/ Seattle, WA 98117 billbeskimo.com SCIENCE HOBBYIST web page