Recent content by buzachaka

I would like to be able to determine the srf theoretically. The project requires the inductors to be printed on circuit boards and I need to know the parameters beforehand. Why can there be no easy answers.

Is there a model for determining the self resonant frequency of a flat spiral inductor? I can determine the inductance but the capacitance is escaping me. Thanks for any help.

Thank you so much! There's an arduino library for just the counter i need. Huge help.

The idea has been bounced around, and i thought to see if anyone here had any guidance before i tear into the literature. What kind of circuit is necessary to determine the frequency of an rf signal? The situation: An rf transmitter is pumping out waves (no modulation or data to be decoded)...

the electrodes are 316 ss but platinum is a little out of the budget. The capillary electrodes used in the lab meters are too delicate for the open water..had to go with a bit of beef! and that means a lot of metal.. the problems would be a lot fewer if i could use a gold alloy.. but it would...

Its certainly not a perfect answer, and there is definitely merit in what your suggesting. By allowing the micro to trigger the pulse timer and then switch to recording data through the ADC, the slight delay eliminates some switching noise and eliminates artificial timing constraints outside...

in salt water, the corrosion is immediate and readily apparent in the calculations. A second of current flow would see a 10% drop in voltage.. more depending on the salinity. I haven't done the calculations yet (response time for the chips, and the micro) but I'm shooting for ~500hz to keep...

I am using two analog outputs and two analog inputs connected to the electrode and using a serial connection to output the data. The problem I had using the pwm was that the voltage signal coming from the analogue output is a square wave. The square wave was was picked up exactly as...

The sensor is a proprietary electrode. Build like a brick ****house so it can be left in the ocean for weeks.

the pwm output is read by the input as a series of '0' and '1023' pulses (tried it before i started thinking about the nature of a pwm signal), the average of which is the specified voltage; The high frequency of the signal means you don't notice when you use it to light an led or drive an...

I'm giving the microcontroller a try, and so far it looks promising. The problem that i ran into was the pwm analog outputs don't provide a proper voltage signal for a dc sensor. The solution i have on the bench now is similar to the schematic from vk6kro but with the outputs fed into pair of...

final question: Is it possible to use a 4 or 6 transistor configuration similar to an h-bridge to replicate the DPDT relay. I've build the timing circuit and it works fine with the relay, however with the number of cycles necessary per minute, the relay will have a very short life. Something...

I think the DPDT relay is going to be the tune for the project. There are 64 electrodes in the array so using microcontrollers might push past the meager budget. However, the microcontroller solution is inspired and I have set out on making one for bench testing of samples. Thanks vk6kro...

I am a ecologist and I have been playing around with a water conductivity sensor, however in seawater there is the obvious oxidation issue. I have found that with the right correction factors and with the polarity frequently reversed, the electrodes have reasonable accuracy. The Question: Is...

I have the same problem and am completely stuck. I know that the coefficient of diffusion and Concentration values are equal between the two situations... but am completely at a loss of how to manipulate the equation to determine the time. .. need a little push.