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    Need ideas for a secure short range (3m) wireless system.

    So, I am working on an alarm system for my bike. As apart of that system, I would absolutely love to have it recognize me from a short distance, say 1 to 2 meters away, and deactivate the alarm and turn the accessories on. For that to work, I would obviously have to keep something on me that...
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    Some questions about an AVR based oscilloscope.

    So, I am looking at this project here: http://www.serasidis.gr/circuits/AVR_oscilloscope/avr_oscilloscope.htm I am not actually interested in building an oscilloscope, I am more interested in building a 120-240 vac 50-60 hz signal analyzer. I would like to build something for monitoring the...
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    How do I create an inductive switch?

    How do I create an inductive switch? I know you can buy them, but I'd like to make one. Does anyone have any one know where I can find a circuit diagram of a simple inductive switch? Thanks!
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    [SOLVED] Dropout voltage concerns.

    I'm trying to build a basic power supply for a few of my electronics, which include my desktop speakers. My concern at the moment is the voltage dropout rating. I've never built a 12V regulated power supply that runs off of a 12V battery. I was looking at a LT1085CT-12 from Digi-Key. It has an...
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    How can I clean some dirty AC from my generator?

    I'm not sure if this is the right forum to put this in, I'm not even sure if this is the right site to post this in, but I have a diesel generator that produces 120V AC via a badly regulated alternator. It was actually causing our ACP UPS's to go nuts and click on and off repeatedly. I finally...
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    [SOLVED] Is there a way to increase the breakdown voltage of a zener diode?

    Is there a way to increase the breakdown voltage of a zener diode? For example, take a 6v zener and combine it with a 1v zener to get a 7 volt zener? Maybe they make some kind of variable zener or an IC that would work like a variable zener? Thanks!
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    Can someone help me identify this part?

    I'm not sure what it is, but it appears to take 120V AC and turn it into about 18V AC. The only markings on it are 564K 400V, not very helpful. I've taken a couple of photos and drew up a wiring diagram. In the photos, it is the large red thing. As far as the schematic goes, R1 is a 100 ohm...
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    How do I calculate the voltage drop of a full wave bridge rectifier?

    This should be fairly easy to do, I just don't know how to do so, I was hoping someone here could help me out. I built a full wave bridge rectifier using 4 diodes. I put 116V AC for my input, and I got 103.8V DC out. I'm trying to figure out what my output is when my input is, for example, 125V...
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    Headphone jack to antenna jack?

    Hey, can someone tell me how to take the signal from a CD player's headphone jack and plug it into the antenna jack of my car radio? I'm not looking for a FM transmitter or anything like that. I want to unplug the car antenna, and plug the CD player into it. Is the headphone jack digital or...
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    Workings of a basic calculator?

    Now, we use calculators on a day to day basis, but how do they work? Most of us know that a basic calculator has a basic IC to perform the algorithms. I had a few questions I was hoping you could answer about this. Everything in electronics deals with logic. If a condition is true, perform this...
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    Any math'a maexperts out there? Need help rearranging this formula...

    I have this formula: How do I work this formula around to equal R2? I tried a bunch of times but I don't know how to do it I guess... Thanks!
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    NPN transistor circuit - Is this right? I doubt it...

    Hi, I drew this circuit in hopes it will replace my reed relay, but I do believe this is wrong... The idea, is to make a positive signal control a negative signal. Thanks!
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    Where can I buy FeCl3?

    Where on earth do you ferric chloride? I keep seeing pictures of tubs of it... Where do I get the FeCl3?? Thanks!
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    Is there a big difference between an FM transmitter and an FM receiver?

    I have a stupid little thingy that plugs into the headphone jack of a CD player or similar device. When it's on, it picks up the output and transmits it to the 88.1, 88.5, 88.3 or 88.7 FM band. But it's always staticy! I don't know if it is the circuit of the device or maybe those channels? I...
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    What makes a good solder desolder station?

    What makes a good solder desolder station? I am considering getting one, but If I do get one, I want a good one. Then, what are we looking at in terms of price? Thanks!
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    Is there a way to make DRL gates oscillate?

    Is there a way to make DRL gates oscillate or do you need capacitors and transistors and ...??
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    Could some one please explain to me how a DRL...? Wait! one more thing!

    Could some one please explain to me how a DRL AND gate works? I looked it up online, but I just don't get it... http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/diodgate.html http://hagar.up.ac.za/catts/learner/andria/tme880dice3gates.html...
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    How can I cascade 4017s?

    How can I cascade 4017s? I know that it is possible but I do not know how. Unfortuantlly, they don't have a cascade option built into them.... Any ideas? Thanks!
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    Dead accurate 1Hz clock signal???

    I'm building a clock and would like to produce a steady 1hrz signal. Obviously, the more accurate it is, the better! Now, I know it's almost impossible to get exactly 1 pulse per second, but I defiantly want it to be close. Any suggestions? Thanks!
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    Binary clock :)! Any one familiar with binary counters?

    Ok, I finally figured out how to do my clock..., I think. This is what I came up with: I have a few concerns.... First, does anyone see any problems with it? Second, please take a closer look at how and when it is reseting. Will it work that way? Third, I need a 6-Bit Binary Counter, that...
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