Search found 106 matches
- Mon Oct 06, 2008 4:26 am
- Forum: General Discussion
- Topic: Can not find spiral
- Replies: 16
- Views: 7426
- Thu Sep 18, 2008 12:02 pm
- Forum: General Discussion
- Topic: Stringed Instrument Tuner, Ideas?
- Replies: 30
- Views: 15580
- Thu Sep 18, 2008 11:40 am
- Forum: General Discussion
- Topic: Incandescent lamp longevity at half rated voltage
- Replies: 18
- Views: 8114
- Thu Sep 18, 2008 9:34 am
- Forum: General Discussion
- Topic: Stringed Instrument Tuner, Ideas?
- Replies: 30
- Views: 15580
Hi again, Little Update here... I tried a 10 percent duty cycle and it seems to help a lot. It appears that the main problem was with a 50 percent duty cycle the eye picked up too much of the vibration and so it became a bit confusing. With only 10 percent the eye only sees a fraction of the string...
- Thu Sep 18, 2008 8:49 am
- Forum: General Discussion
- Topic: Incandescent lamp longevity at half rated voltage
- Replies: 18
- Views: 8114
Hi there, There might be something to be said about resistance vs Triac phase control vs Diode. ...... whereas the pure resistance method ( two bulbs in series ) would not. This could make a big difference. ------ These three techniques are all different and need to be evaluated separately. Puting ...
- Thu Sep 18, 2008 8:18 am
- Forum: General Discussion
- Topic: Digital television broadcasting frequencies ?
- Replies: 10
- Views: 4919
- Mon Sep 15, 2008 10:00 am
- Forum: General Discussion
- Topic: Digital television broadcasting frequencies ?
- Replies: 10
- Views: 4919
Re: Digital television broadcasting frequencies ?
Isn't 88 - 108 MHz the FM Radio broadcast band?Externet wrote:Hello all
Anyone knows how will the aired RF spectrum look like next year ?
(MHz) --- 30 to 50 stays ? 50 to 88 gone, 88 to 108 stays; 108 to 174 stays, 174 to 220... 220 to 470.... 470 to 900 .... 900+...
Miguel
- Thu Dec 20, 2007 6:12 am
- Forum: General Discussion
- Topic: Merging / splitting DC/AC signals sharing a conductor...
- Replies: 16
- Views: 8082
Thanks. Did not know the inserters were available commercially. As even the small ones are somewhat bulky for my application, I still prefer to calculate my own. The consumption of the camera is 150mA. The wire gauge of the coil should not drop more than a volt in insertion (~10%). Am fine there. A...
- Thu Oct 25, 2007 6:50 am
- Forum: General Discussion
- Topic: Can I dim a switching power supply?
- Replies: 5
- Views: 3605
- Mon Oct 22, 2007 6:03 am
- Forum: General Discussion
- Topic: Universal motor...
- Replies: 5
- Views: 3099
Now, 120 VDC is another story! No, at 120VDC it may take too much current and / or overspeed. An universal motor is just a series wound DC motor (that is, the field winding is connected in series with the armature), but it has two small differences: >> As the field winding will have AC, the magneti...
- Thu Oct 18, 2007 6:13 am
- Forum: General Discussion
- Topic: 480VAC Indicator Panel LED
- Replies: 22
- Views: 11772
- Tue Oct 16, 2007 6:34 am
- Forum: General Discussion
- Topic: Automatic voltage selecting transformer
- Replies: 7
- Views: 3967
- Fri Oct 12, 2007 6:13 am
- Forum: General Discussion
- Topic: 240V transformer on 277V line?
- Replies: 17
- Views: 8400
As a side note, as the input voltage to a transformer is increased the excitation current increases, causing the copper and the core to heat up more than at lower input voltage. At some point it becomes impractical to use the transformer at that voltage. The current that the transformer takes under...
- Tue Sep 25, 2007 6:28 am
- Forum: General Discussion
- Topic: Amp meter for 1Hp motor
- Replies: 12
- Views: 5740
The only time I've seen an ammeter permanently mounted on woodworking equipment was on a surface planer where the ammeter indicated if you were taking too large of a bite out of the material being planed. The same machine had a regular magnetic motor starter involved, so had overload protection. I ...
- Mon Sep 10, 2007 5:41 am
- Forum: Computer Programming
- Topic: Protecting PIC inputs?
- Replies: 16
- Views: 13610
If the input pin can go to +10V then the current may be 10V/1k = 1 mA into a 0V supply or (10V-5V)/1k = 500 microA if the supply goes up to 5V. If tte minmum current used is more than the number of inputs times 500 microA there is no problem. If not, you can add a zenner (perhaps 5.5V or 6V) across ...