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  1. J

    Transistor as a switch

    Nose, re-read my above post. I edited it heavily after I replied because I realized I misunderstood what you wrote. Hopefully it makes sense. That formula you posted is not anything I have ever seen.
  2. J

    Transistor as a switch

    I don't understand this at all. A NPN transistor turns on when the base voltage is more positive then the emitter voltage by .7V. That should be the case when the output of the arduino is HIGH 5V. Then Rb is used to set the base-emitter current. It is this base-emitter current that is multiplied...
  3. J

    1104 led rectangular array

    Photons are photons, I believe everything you are saying. But in my experience I would not waste my time. LED lights would have had to come a long way in 6 - 8 years since I last used one. That being said, maybe they are as powerful as the HID lights these days. I can't deny or confirm that...
  4. J

    1104 led rectangular array

    Photons are photons, I believe everything you are saying. But in my experience I would not waste my time. LED lights would have had to come a long way in 6 - 8 years since I last used one. That being said, maybe they are as powerful as the HID lights these days. I can't deny or confirm that...
  5. J

    1104 led rectangular array

    From experience, I can tell you one thing that an LED can't do. It can not penetrate the canopy. The same thing with a CFL or florescent over an HID light. You will get some results with the CFL/florescent, but they will never be as good as their big brothers. Gonzo and Bobk both bring up cons...
  6. J

    multimeter recomendations

    fluke But, you really haven't told us anything. So I will elaborate and we'll see if you wish to help yourself. What features are you looking for in a meter? What price are you willing to pay? Are you looking for more features at a reasonable price or just a few features at a higher...
  7. J

    NEWBE

    Lay off the caps. You say it has two primary coils? Then it is probably rigged up to run from either 240V/120V. Depending on how it is wired.
  8. J

    Antenna help

    Exactly what my first impression was. Instead of thinking about me (my money) they are are more worried about improving their own network to increase further sales. Well at least someone agrees with me, whether that makes a difference, only time can tell. I did happen to read a thread on...
  9. J

    Help with a flip-flop circuit

    shift register? Every time a new input is seen all the previous inputs are shifted. If you ran the flip-flops off the output of the shift register this could work. Apart from that, I assume this could be easily done with a uC.
  10. J

    Antenna help

    If I knew how, it would have been my first option. Those attenuators a not cheap either. $20 bucks? I actually called verizon and they are gonna honor the warranty on the device. Supposedly like steve says and I read in the manual. The RHK distance is fifteen feet, supposedly this is how...
  11. J

    Antenna help

    Yes, I just unscrewed it. Same type of external antenna you find on wifi routers. Verizon phones are cdma technology, which is incompatible with gsm phones. So as of right now I am stuck with this device as much as I don't like it. I believe they call it, like oliver stated, a SMA connector...
  12. J

    Antenna help

    please explain more in detail. An external antenna on my device or just an external antenna that is separate from my device that would essentially jam his signal? I looked it up, you are saying that if I attenuate the signal and use another antenna (phasing) providing nulls I can prevent...
  13. J

    Antenna help

    Well let me assure you that is a line of bs. The device requires any broadband internet connection. I don't have verizon broadband. But I bought the device outright for $250 from them. The limit at which you can connect is well, at best, unreliable. Last night I unplugged my device and walked...
  14. J

    Antenna help

    Seems to me that a simple firmware update would allow for access list and then reserve one channel for 911 emergency calls. But from reading everything over the internet verizon does not want to do this and I think it is pretty shady. Who are they to tell me who I can and can't share my money...
  15. J

    Antenna help

    verizon is cdma based wireless technology, where att and others like the small guys are gsm 1900. So no I don't believe they will work on each others network. But, with that said I think all cell phone companies need to provide 911 service on any cell phone with or without service on any...
  16. J

    Antenna help

    Well in the states where I am from every femtocell device needs to have 911 access and everyone has to be able to access it. So verizon won't let you select certain devices, they only let you select certain devices for priority. So in other words, if all the channels are used up and I have...
  17. J

    Antenna help

    Davenn, I think this is probably a good one for you to answer, but I will take anyone's advice. :D I have one of these Network Extenders, femtocell, devices from verizon. Recently my neighbor informed me that he was gonna cancel his landline and internet to get a pre-paid cell since he gets...
  18. J

    Variable power supply

    Well if it went to 1.64V then it surely will output 3V. If you don't want it to go below 3V, then use a regular resistor to give you the 3V min and then in series add a pot to get your max V. When the pot is at 0Ohms, then 3V will be the min.
  19. J

    Variable power supply

    its called algebra. :) 15V = 1.25(1+R2/240) then you solve for R2. R2 = 2640Ohms. Fit a variable resistor larger then 2640Ohms and you will achieve 15V BTW, you formula was wrong, have another look at the datasheet. It is listed right under the first diagram. Where is says typical applications...
  20. J

    Oilfield/Industrial electrician

    Hi welcome edit: nvm, i am a ****ing idiot, this is the introduction section. :)
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