Latest threads in Hobby Electronics Basicsshow only best voted threads

Subject Author Posted Replies
 
power supplies
I've got a couple of AC/DC power adapters that went to various things that are no longer around. They have various output voltages and currents. Would these be useful as a power supply into my...
6
6
 
MATERIAL MAY HELP AUTOS TURN HEAT INTO ELECTRICITY
Researchers have invented a new material that will make cars even more efficient, by converting heat wasted through engine exhaust into electricity.
1
1
 
LED info
Stupid question probably but what does the (T1) specification for LED's mean? H. Dixon
5
5
 
Cleaning a Female BNC Coax Connector?
The male and female parts of the connector are used together outdoors. There's no trouble disconnecting them, but they are both yellowed (rust?), so the connection seems broken. The male part was...
2
2
 
charger with constant current
Hello, I am attempting to charge a battery and I would like to have a feedback on the approach. I have a 18v supply coming from a generator and want to charge a 12v battery. First I cannot constant...
6
6
 
Princeton scientists spy an electron dance
A team of scientists led by researchers from Princeton University has discovered a new way that electrons behave in materials. The discovery could lead to new kinds of electronic devices.
 
Chopper circuits for contactor coils
I am looking to reduce the power used by standard industrial 5 and - 12kw contactor coils and think that coil chopper circuits will do the job. Now I need to find them, or make them, for 240v and 24v...
4
4
 
Resistor Wattage?
I have a regen radio that uses one type 30 triode tube with 2.0 volt, 60 mA filament. The radio had two 33 ohm 1/2 watt resistors wired in parallel for 16.5 ohms in series to the tube filament to cut...
3
3
 
RF cooling -- so interesting!
Hi: Just how can microwaves be used to cool something? Usually they heat things up. Thanks, Radium
10
10
 
activating reed switch
Hello, I made myself a small electromagnet to activate a reed switch using a 6v supply. The problem is that I am pulling 3 amps, I do not want the electromagnet to be bigger by making more turns, I...
9
9
 
ELF radio needs more watts than MW radio?
Hi: I remember reading somewhere than ELF [Extremely Low Frequency] radio transmission is inefficient because it requires to much power. If that is the case, wouldn't MW [Medium Wave] radio...
67
67
 
Permanent magnet question
Hello, I have a permanent magnet and I just finish building myself a gaussmeter. However it shows me that every magnet I measure has a higher gauss level for the south then the north. Do magnet have...
6
6
 
First project - stumped
I'm using Slone's Tab book to learn the basics. It's pretty good so far although once in a while the book takes bigger leaps so I stumble a bit. What I've got so far is the the two 24V transformers...
2
2
 
My Thanks to Dave Platt
Thank you for the detailed answer to my question about re-activating a rooftop TV antenna. I have sent a copy of your answer to my roofer friend. --- Joe
 
Substitution possible?
Hi - newbie electronics learner here. I'm building a basic 12/24V power supply and one of the components called for is a 6A, 200 volt PIV bridge rectifier. I have one that is 6A, 250V. Shouldn't I be...
2
2