Latest threads in Hobby Electronics Basicsshow only best voted threads
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Wanted: A 'joule thief' style circuit design...
... that I can use to drain alkaline cells and push the 'charge' into either a lithium-Ion cell (for a flashlight), a phone or a powerbank. I have a combined wireless doorbell - inside/outside...
15
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4 years ago
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15 | |
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Colpitts oscillator
Hi, I'm following instructions here ( to build a discrete components above MHz oscillat or. I could not find a 150nH inductance so I used one I found on spare componen ts, which has I think rather...
5
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4 years ago
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5 | |
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Calculate run time of battery to a specified voltage
I want to calculate approx run time of a D cell with a capacity of 13,000 Mah. I assume that Time(H) = Capacity(Ah)/Current(A) equals a final battery voltage of 0 volts which will not work in my case....
11
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4 years ago
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11 | |
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LED RF Noise Evaluation
Hello, I have experienced what seems to be RF Noise that is generated from LED lighting. I don't have the exact spec's but just wondering if anyone here knows of what to look for as to packaging...
8
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4 years ago
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8 | |
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Independence of Capacitance from Dielectric
Hi, A simple carelessness has caused the famous formula for the electrostatic p otential to be written wrongly while in its correct form we must use a term showing electrostatic field arising only...
2
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4 years ago
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2 | |
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All Ob A Sudden, Starter Motors Is So Small & Light You Can Carry 'em Home In A Filmy Shoppin Bag
Summin didn't look right. The replacement starter motor was 2/3rds the dia of the original, mebbe haf the wait. I tink, WTF? Weren't all them optimum nummers well settled back in the early Nicolacene?...
5
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4 years ago
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5 | |
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Will this work safely?
Pressing the door button of my commercial wireless door bell causes the mains-powered speaker unit in the hall to chime. Rather than buying another speaker unit I thought I'd make a simple extension...
10
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4 years ago
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10 | |
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Inductance calculations
Somewhere there must be a formula for the inductance of a hand-wound coil. Air core, one layer of wire (of given swg) close-wound, diameter of former (cardboard, probably inside of toilet paper roll),...
5
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4 years ago
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5 | |
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Harmon divider 10:1 and 100:1
Just found this neat method to make 10:1 voltage dividers. Not as important now that you can get such precision resistors, but with this you don't need them. Also measurable on a single voltage range...
3
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4 years ago
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3 | |
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Anyone with plc experience?
I was looking for a ready made timer for a hydroponic system I'm tinkering with and came across some el-cheapo PLCs on Amazon, and figured this would work lots better than a timer that would need a...
5
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4 years ago
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5 | |
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GFCI/lightening
I had a lightning strike hit an antenna mast and it took out a lot of electronics in my house. It actually popped circuit breakers in the house along with taking out the TV, modem, KVR switch, low...
2
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4 years ago
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2 | |
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The Tardigrades
We can't just leave them there to die.
1
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4 years ago
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1 | |
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Current vs. wire gauge
What current can 18AWG wire carry? And, more usefully, is there a table somewhere giving this info for all the usual gauges?
7
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4 years ago
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7 | |
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12 Vdc led running hot
I bought some 12 VDC 5 mm red leds. They work find but... when I touch the wires going into the led, they were hot enough that I had to remove my hand. That does not seem normal. Thanks.
11
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4 years ago
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11 | |
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Rebuild computer speakers
I bought some Inland Pro Sound 2000 speakers from a thrift store. It is an amplified system putting out about 7 watts. They sound pretty poor. I remember making my own 8 ohm speakers years ago using a...
2
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4 years ago
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