Recent content by Curl

Confirm means I made a hypothesis and the answer I got matched my hypothesis. The other 2 engineering ideas I had this week turned out to already exist in industry. Things like this happen to me every week that's why I'm fully expecting it. I'm getting to the point where I think I can't make...

If all the contacts don't close at the exact same time then there will be arcing I see. Nothing can be built perfect so this is useless in breaking high inductance circuits. It then gets beat by normal mechanical switches and transistors on every other application. So as I suspected, this is...

The reason why I did not show the details is because it's irrelevant. I came here to find out if a relay like this is useful, I didn't come here to get a design review. The customer doesn't care how the device works they only care about what it can do, so I want to get opinions from that...

Baluncore I never said anything about making a billion off of this; it's a very simple idea and I'm 99% sure that someone has already done this "trick" in design. All that you said is true and I probably know it better than you, I don't get how you got the sense that I'm all in love with the...

The reason I thought about it was because I was working on a project where I wanted to create a small spark using an ignition coil off a car. It worked fine using a normal switch except I noticed I got 2 sparks, one in the switch and one across my gap, so I needed a way to open the switch much...

Hi I had a neat idea for a relay design, basically its a relay that takes very tiny movements to open/close a circuit, I.e. I can make a 10 micron movement to create/close a 1mm gap very easily and in a small package (3mm by 10mm by 20mm say) and with a fairily large contact area (for that size...

Thanks guys, you are right that a band-pass filter is what I should use for my situation. Here's a dumb question, but for the Sallen-Key type filter, I cannot use electrolytic capacitors correct? Should I buy the thin-film caps for this purpose?

Making resonance using "simulated inductor" (op amp) I want to have a circuit that responds strongly (gives me a good measurable voltage) to a 10kHz sound input. To do this, I thought about hooking up a microphone and making a resonance circuit (using inductor and capacitor) to amplify the...

Sorry for the dumb question, I'm not good at mathematics, but: what is 1/i ? 1/i * 1/i = 1*1 / (i*i) = 1/-1 = -1 ? If so the number, 1/i has the property that (1/i)^2 = -1 which is the definition of i. BUT, 1/i is not equal to i because if it did: 1/i * i would be i*i= -1...

I want to solve the one-dimensional heat PDE backward in time ∂u/∂t = -∇2u = -∂2u/∂x2 , x element of [0,L] Basically, I want to find what the initial temperature profile u(x,t=0) should be such that after some time t1 of diffusion, I am left with the bar at a uniform temperature u(x,t1)=c...

I want 5V at 850psi. I used a 1.4k resistor, a 1.7k resistor, and a potentiometer with everything from 1k to 3k. The output pin, measured with the multimeter, was always 5.4V, NOT changing at all even though I was putting 0-100psi on the sensor. Is it fried? I could try to see if I have another...

I machined my own 7-segment display out of clear polycarbonate, each segment is about 1.5" long (it's a rather large display) and now it's time to add the LEDs. Turns out that the usual LEDs with the epoxy lens focus the light too tightly on one spot, so I get more of a dot rather than...

I want to make an LED display that can show 3 digits, so I have 7 segments for each digit for a total of 7x3=21 LEDs. I need this to display some data from a sensor I'm capturing with an Arduino, and I want to use the same Arduino to run the display. How can I do this without flickering the...

For a point source, correct.

what do you mean "try" it?