New diode setup update
Here's the hot setup. Outline -->
Electrometer, batteries, and diodes to be tested are inside metal chassis. Electrometer is always off except for while measuring diode DC voltages. Electrometer output goes to *very* thin twisted copper enamel coated wire, which goes through a very small chassis pin hole. Immediately outside of the chassis right where the twisted wire comes out of the pin hole is a high input resistance op-amp, a FET op-amp will work great. Also connected to the twisted wire immediately outside the chassis is a capacitor and also a shunt resistor, which will shunt any measurable external RF noise. The FET op-amp output goes to a LCD panel meter or DMM.
This type of setup will prevent all measurable external RF noise from entering the chassis. The wires that go to the DMM and the DMM itself will pickup a small amount of RF noise, which will travel down the wires that go to the FET op-amp, which is nothing but a short relative to the FET input resistance. The circuit would be a capacitor, say 1uF, a resistor, say 150 ohms, and a 10Tohm (10e+12 ohms), all in parallel to each other. So which path do you think the current will take. It surely will not take the path through the 10Tohm resistance, which is the path from the FET op-amp output and input stage. So the capacitor and 150 ohm resistance short any external noise that would normally enter the chassis.
The reason the FET op-amp, capacitor, and shunt resistor need to be as close as possible to the chassis is to eliminate as much external noise pickup as possible. Pick a FET op-amp that is very small.
Here's a simple schematic -->
The switch that is between the DUT and INA116PA is a simplified symbol. Ideally you want a two way switch such that it reverses the DUT relative to the INA116PA.
The components next to the FET op-amp are a capacitor and resistor, believe it or not. You might need a magnifying glass. :-D
Further details will be posted in future blogs. Details such as the method of turning the electrometer on and off, and the type of switches. I have used Mercury tilt switches. For my next new setup, I may continue to use such tilt switches, but for the Grand Final setup that will be taken to demonstrate the diode array to Universities and such will most likely use ultra low power small latched reed relay switches that will be momentarily powered by an LED shining light through a small pinhole and picked up by a photodiode.
Created on 2009-07-02 20:11:01 by EnergyMover
Diode replications, FE diodes, FE Misc devices, Free energy, Free energy devices, Science, Testing procedures, Diode, Diode replication, Free energy, Testing procedures