Recent content by Baluncore

The ultrasonic transducer sits between the tank and a counterweight. The counterweight can usually be adjusted to match and work against the tank full of water. It may be that the mounting of the transducer or the counterweight has become loose or maladjusted. Check the mountings, and look for a...

Maybe reaction wheels are one way to control the ball. https://en.wikipedia.org/wiki/Reaction_wheel

Look for HgCdTe (MCT) photodiodes, or LW IR LEDs. Multiply the room temperature dark current, (probably less than 10-9A) by 0.25V to get the power, ≈ 0.25nW. To evaluate if it is a cost-effective way of harvesting energy, compare the cost of manufacturing the diode, to the energy harvested...

I missed this thread earlier, so now is the time to acknowledge all the previous work, before I attempt to handwave a consistent, and hopefully realistic story. For this analysis I will assume that the plastic bags are impermeable barriers to water, and we can extend that impermeability also...

Solar panels do not work in the dark. They are designed to operate at visual wavelength, in sunlight. Indoors, there will be thermal radiation from the surrounding structure. You know it has a temperature of about 20°C, so you can work out the black body radiation curve; λpeak = 9.898 um, in...

There is little energy at those wavelengths because the voltage is low. Electron energy can be specified in eV. Longer wavelengths have lower energy, lower eV. Given wavelength in μm; Energy; eV = 1.23984 / λ μm Infrared energy ranges from 1.653 eV to 0.00124 eV Near IR: 0.75 μm to 1.4 μm ...

This LTspice model is sufficient to model the signal passing through a via. T1 is the line on one side of the PCB. T2 will become the via, if it is shortened. T3 is the line on the opposite side of the PCB. Values that are unusual are marked with an asterisk, so they will not be missed or...

Tektronix produced this 114 page reference. Time-Domain Reflectometry Measurements, by James A. Strickland. https://w140.com/tekwiki/images/1/1d/062-1244-00.pdf

Here is a simple TDR simulated in LTspice. Remove the .txt extensions from both files, then run the LTspice file.asc Start by changing the termination impedance and notice how the Vin changes later due to the reflection.

TDR is a plot of impedance (driver voltage) against reflection time. Z = √( L / C ) You cannot say if it is the inductance or the capacitance of the transmission line that has changed, only that the ratio and resulting impedance has changed. There is an HP beginners guide to TDR here. HP...

Then you would have seen a "tripler" circuit in a CRT monitor, driven by the horizontal output transformer. https://en.wikipedia.org/wiki/Cockcroft%E2%80%93Walton_generator

That is because the output voltage is to be negative relative to ground, as in the diagram in post #1. I think in post #1, they are very old polarised condensers. The curved plate is the negative external can of an electrolytic capacitor. I draw parallel plates in post #8 with ± symbols to...

You have two tracks with known impedance, joined through the PCB by a short cylindrical via. The via will probably not match the impedance of the tracks, so it will appear to be a quarter wave transformer with the via length, adjusted for velocity factor √Er. Usually, only ground and power are...

Welcome to PF. This is a problem of understanding how the circuit works, assuming perfect components. If you specify the frequency, input voltage, output current and ripple voltage, then the values for real components could all be specified. I have used that circuit successfully at 50Hz in a...

I have not got it running yet. Your gate bias was a problem. See attached.