Recent content by Jeff273

Or that the voltage across a cap: Vc = \frac{1}{C} \int i_c dt

A diode clamp works by limiting the voltage to one diode drop above the clamp voltage, typically you want to protect the input to a sensitive device. https://www.physicsforums.com/attachment.php?attachmentid=3340&stc=1 While Vin is below about 5.7V Vout will match Vin since the diode is...

The resistance of anything is R = V/I. The resistance of the filament at a given point is the slope (derivative) at that point. There are two ways to get this. You can manually (with ruler and pencil) approximate the slope at a point, or you can curve fit over a protion of the curve around...

You mean like a diode clamp on a power line?

Nope. The voltage at the RC node is always zero (this is a virtual gnd). With Vin at zero, the circuit looks like this: _ Vout | | - I C <--- | + gnd ____ R __________|...

Russ, Nice photos. Are you shooting from Philly? What are your skies like? I'm in rural south-central PA and I have maybe mag 5.5 from my yard. Have you done any deep-sky work? If so, I'd be interested in your results given the high light pollution in Philly.

You need to be a LOT more specific. If you mean measurements of cosmological expansion, all measurements are redshifted. If you mean the local volume, then they are dependent on local motions and I don't know the mix. What are you asking?

EvLer, Yes. Evaluating, you will have: Vc = \left[\frac{1}{RC} \times -2(t)\right]_{0}^{1} \plus+ \left[\frac{1}{RC} \times 0(t)\right]_{1}^{2} You can see that the second term is zero forever with Vin = 0.

SGT, Ignore the math for a second and check the circuit. When Vin is at zero the current through R is zero. Since there is no current flow at the virtual node (which is always at zero volts - the reference - in this circuit) the voltage across the cap as measured at Vout will hold at...

Vc = \frac{1}{C} \int_{0}^{t} i_c dt In your circuit i_c = V_{in}/R so your form, Vc = \frac{1}{RC} \int_{0}^{t} V_{in} dt looks right. So, assuming Vc started at zero at To with Vin = -2V, you have, Vc = \left[\frac{1}{RC} \times -2(t)\right]_{0}^{1} When you switch from...

How much gain do you want?

Just reread your post. Do you want: 1) The AC component only with an option to pass the AC + DC or 2) The AC component only with an option to eliminate the AC and pass just the DC component?

Add another LP filter as shown. You did not specify a response time, so you'll have to calculate the R and C. A sufficiently low-pass filter will pass the DC component with some ripple that you must define as acceptable. Its a trade-off between response time and AC ripple...

Interesting. Now I just need a couple of Mossbauer Spectrometers.

JesseM, I completely agree that mutual dilation must follow, as you say, from existing observations of dilation in satellite and aircraft experiments. I've been trying to devise a way of actually showing it happen. I have access to high speed electronics and instrumentation able to measure...