Latest threads in Hobby Electronics Basicsshow only best voted threads
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What kind of battery charger ?
I brought a Ansmann ALCS2-24A' auto voltage detacts charger from a shop " Element 14". I encounter a problem. My 6 volt 10A lead acid battery at its weakest measure 3.59 volt when I connected to this...
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13 years ago
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Yagi TV/FM Antenna--See Through Trees?
Is it possible for an antenna to see through a thicket of trees? I noticed a picture on a web site of a UHF antenna in an attic.
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13 years ago
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TV Coax--300 vs 75 ohm
Don't TVs (analog) require 300 ohm coax? Can 300 and 75 be mixed? I went to use a old TV the other day that I had hooked up to about 25' of coax, but needed an extension of about 12'. There were zero...
12
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13 years ago
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12 | |
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lenses and the 2nd law
This may be a dumb question, but anyway.... A lens focuses energy, does it not? That's its purpose. So given a large radiating source, the lens concentrates a dissipating spreading wave, down to a...
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13 years ago
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duty cycle and sine waves
I was talking to a guy currently in college who had a lab in which he had to calculate the duty cycle of a sine wave. The professor provided a formula which he didn't remember. What's this about? In a...
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13 years ago
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11 | |
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High Gain Antennas
** Hi all, inspired by a series of posts on the subject of antenna gain - I did a little Googling. My quest was to find the highest gain antenna ever uilt - I guessed it might be a large parabolic...
3
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13 years ago
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why triac blows by non-dimmable CFL even when its off?
I am trying to use non-dimmable CFL with triac dimmer but just to turn on and off the lamp without dimming. 13W CFL lamp flickers even when its off. This must have been caused by continuous leakage...
8
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13 years ago
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Antenna question
I'll be grateful if you could explain this: Is antenna gain in dB related to voltage or to power? For example, suppose there are two receiving antennas with different gains, but identical in...
49
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13 years ago
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49 | |
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RC's and thermal modeling
So from a previous thread, it was suggested by John L. that I try some RC modeling. I did that today and the results were not what I expected. I sent a step voltage into a single RC (R=1 C=1) and then...
7
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13 years ago
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7 | |
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Circuit collections
I have some circuit collections here:
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13 years ago
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DIN Rail Terminal Block - Colours ?
Apologies if this isn't the right place. I've read recently (and can't find now) about DIN Rail terminal blocks and it listed a nominal Colour & Use chart. ie in the UK Green/Yellow is considered an...
1
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13 years ago
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heating elements
I've been wondering how the heat controls on high power heating element in electric stoves, baseboard heaters and the like work. Is it PWM?
9
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13 years ago
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9 | |
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Best way to generate 4th power for signal ?
Could some electronics guru please provide some feedback on this issue ? I want to generate the 4th power of a given signal. The design I had in mind was to have two mixers running in parallel, where...
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13 years ago
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Auto Alarms Designed To Draw 100 Amps
Require auto alarms to include circuit that pulls over 100 amps as long as the alarm is on. If the alarm isn't shut down in 15 - 30 minutes by the owner the battery goes dead. 1200 watts worth of...
9
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13 years ago
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Some questions regarding band-pass filters
Could some electronics guru please provide some hints to my queries. For a 'four-times' carrier frequency recovery scheme, as used in QPSK, the QPSK signal is fed into a 'power-4' circuit, that...
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13 years ago
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