Search found 309 matches
- Thu May 12, 2005 6:27 pm
- Forum: General Discussion
- Topic: How is power fed back into the grid?
- Replies: 18
- Views: 9767
Re: How is power fed back into the grid?
A synchronous generator lets the line make up the difference between its output and the power requirement. Its safe because it stops generating if the line shuts down.
- Sun May 08, 2005 11:08 am
- Forum: General Discussion
- Topic: How is power fed back into the grid?
- Replies: 18
- Views: 9767
Re: How is power fed back into the grid?
I saw this thing at a home show maybe 20 years ago.I don't know how good is is just that it exists. Regenerative drives are common on machine tools. They synchronize the firing of scr's to control speed and direction of a dc motor. When the motor has an overhauling load the current is inverted back ...
- Sun May 08, 2005 3:04 am
- Forum: General Discussion
- Topic: How is power fed back into the grid?
- Replies: 18
- Views: 9767
Re: How is power fed back into the grid?
For D.C. you need a "syncronized inverter". It switches whatever voltage is available onto the line at a point from the zero crossing where the the line voltage is less than to D.C. level. The electronics are similar to a regenerative dc motor drive.
- Sat May 07, 2005 2:54 pm
- Forum: General Discussion
- Topic: How is power fed back into the grid?
- Replies: 18
- Views: 9767
Re: How is power fed back into the grid?
If you have a syncronous generator it will fall into sync by itself. You can drive an induction motor above it's syncronous speed to force power into the lines. A generator with it's own excitation may fall into sync on it's own, just make sure it's fused in case it doesn't. Of course the bigger iss...
- Sat May 07, 2005 2:48 pm
- Forum: General Discussion
- Topic: bandsaw blade welder (old one)
- Replies: 26
- Views: 12857
Re: bandsaw blade welder (old one)
A common way to limit welding current is to run a dc current in a seperate winding in the transformer. Sometimes that circuit goes bad.
On a blade welder you have to develope skill to do it right, you can have problems even it it's working ok.
On a blade welder you have to develope skill to do it right, you can have problems even it it's working ok.
- Wed May 04, 2005 4:20 pm
- Forum: General Discussion
- Topic: DELCO Radio info needed
- Replies: 14
- Views: 6124
Re: DELCO Radio info needed
40 to 50 mpg back in '90 when a hybred had four legs!
- Wed May 04, 2005 4:13 pm
- Forum: General Discussion
- Topic: GE 1050 T Conrol Shutdown Help
- Replies: 2
- Views: 1875
Re: GE 1050 T Conrol Shutdown Help
What about we curious people that never saw a 1050?
- Wed May 04, 2005 4:08 pm
- Forum: General Discussion
- Topic: incandescent to led flashlight conversion?
- Replies: 5
- Views: 3057
Re: incandescent to led flashlight conversion?
Dorcy makes a single led aluminum body flashlight that runs on one AAA cell. If it's what you need it would be hard to beat at $6. If you unscrew the body the led is attached to a driver board that is about 1/2" by 5/8". It would be a good retrofit for other projects.<p>Dorcy also makes a ...
- Sat Apr 30, 2005 12:43 pm
- Forum: General Discussion
- Topic: Presence Detector
- Replies: 13
- Views: 5474
Re: Presence Detector
Or you could go to home depot and buy one for 15 bucks.
- Mon Apr 25, 2005 3:33 pm
- Forum: General Discussion
- Topic: Solar panel sleight of hand
- Replies: 67
- Views: 24500
Re: Solar panel sleight of hand
No real need to bash alternative energy,it's already pretty much dead. Conservation and wise use would be much more practical but that seems to be pretty much dead as well. Now we have remote car starters so millions of cars can idle for 15 to 20 minutes before they go anywhere. The horsepower war i...
- Sat Apr 23, 2005 12:53 pm
- Forum: General Discussion
- Topic: Battery Powered Lawn Mowers - Don't Curse - I Know They
- Replies: 10
- Views: 4894
Re: Battery Powered Lawn Mowers - Don't Curse - I Know They
one of the former electronic magazines like popular electronics(not sure) had a construction article on a battery powered mower that sensed the height of the mowed/unmowed grass to find it's way. It had three small rotors with short blades which might have been more efficient than trying to swing a ...
- Wed Apr 13, 2005 3:42 pm
- Forum: General Discussion
- Topic: logic circuits run from 12 volt car batteries
- Replies: 15
- Views: 6924
Re: logic circuits run from 12 volt car batteries
Interfacing logic with transistors can be a challange in itself. A ttl low is often above the .7 volt threshold that will keep the transistor on. If you use the (good) idea of cmos, a low is around 1/3 of supply. Make sure you have somthing that works before you go ahead and build them all.
- Thu Mar 31, 2005 3:19 pm
- Forum: General Discussion
- Topic: stopping a screen saver with a PIC
- Replies: 9
- Views: 4246
Re: stopping a screen saver with a PIC
Leaving the computer open for 15 minutes and then locking it up is a useless security measure. The real question is why isn't there a better way to limit access without inconvenience.<p>I see that cars are using some kind of proximity devices so that the driver can just get in and press a start butt...
- Mon Mar 28, 2005 12:59 pm
- Forum: General Discussion
- Topic: INTERNET RADIO
- Replies: 18
- Views: 9309
Re: INTERNET RADIO
They call it SATELLITE Radio. If you need it to be portable and are willing to buy the reciever and pay twelve bucks a month you can have it. Otherwise leave your computer running it's cheaper.
- Thu Mar 17, 2005 2:58 pm
- Forum: General Discussion
- Topic: 12vac-12vdc
- Replies: 27
- Views: 10324
Re: 12vac-12vdc
I've found that using leds in series and trying to use them as rectifiers is a bad idea. You will have problems with dependability. Use a good regulated supply and a resistor with each led for dependable stable operation.