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  1. Externet

    Solar Based Handheld Led Light

    All the effort, time, parts, making a proper housing where all fits will cost more than : -----> https://www.aliexpress.com/wholesale?SearchText=solar+flashlight&opensearch=true
  2. Externet

    Basic Electronics

    Perhaps this will help too : (+)10V----------50Ω--------A-------30Ω------B------20Ω-------C-----------(-) Must know the current : 10V divided by 100Ω = Current is 0.1A Voltage dropped by 50Ω = 50 x 0.1 = 5V = between (+) and A Voltage dropped by 30Ω = 30 x 0.1 = 3V = between A and B Voltage...
  3. Externet

    In line switch with led indicator

    If stereo : Ipod L. channel >-------------------------. /.---------------------------------------------------> Mixer L. Common--------------------------------------G------------------------------------------------------ground Ipod R. channel >-------------------------...
  4. Externet

    In line switch with led indicator

    Try a double pole double throw switch; one set of contacts branch for the LED indication from 9V and the other set of contacts branch of the switch to ground the audio line for muting.
  5. Externet

    Basic Electronics

    There is no ground on your first schematic. Now, there is no equivalent load or resistance to ground at the ADC pin. And you do not know it. If the equivalent internal resistance at such MCU pin was 1 MΩ to ground, the current flowing through the resistors is 6V divided by 1000572Ω = current...
  6. Externet

    Basic Electronics

    You said first "the voltage drop across a resistor" Now, the voltage at point A in reference to what ? If the positive probe of your voltmeter is sensing A; where in your circuit is the negative probe of your volt meter ?
  7. Externet

    "Simple" light sensitive, Servo Project

    Try this, erasing both R1 and LED. ----> http://www.build-electronic-circuits.com/wp-content/uploads/2013/11/LDR-circuit-dark-detector.png Insert the servo instead, observing polarity. And clarify if you want the servo to work when the photoresistor is illuminated or dark. Other alterations as...
  8. Externet

    Basic Electronics

    If you apply voltmeter probes to points A and B, the voltage read across that resistor will be 10 Ω times the current in Amperes flowing trough the resistor. If you do not apply the probes to the circuit but just want to calculate the result, the answer is the same, resistance times current.
  9. Externet

    Maximum socket outlets

    Just in case you have a misconception, a circuit breaker does not 'supply' a number of Amperes; it is there to protect the wiring. If the outlets use 1 Ampere each, you can have 20 outlets on a 20 Ampere breaker before trips. If the outlets use 10 Amperes each, you can have 2 outlets on a 20...
  10. Externet

    Wifi extender parabolic dish and other methods

    See the low aiming angle ? Picked from the middle of a forest a distant open wifi/internet signal for 3 years; from so far that never was able to find where. Yes, maaany miles range. ----> http://s588.photobucket.com/user/Innernet/media/HFuWave.jpg.html?sort=3&o=111 At the focal point, an...
  11. Externet

    Need a 15Wh battery that can charge in 20 minutes

    Skip over what inverter ? Feeding 20?VDC alone to charge a pack will lack temperature and failure safety control lines. Its internal controller will refuse to charge the pack.
  12. Externet

    Need a 15Wh battery that can charge in 20 minutes

    I would use an off-the-shelf power tool (drill) LiIon battery pack and its charger, and regulate the driven device input to 5V with a LT1083-5 or similar regulator. A second battery pack kept charged decreases charging time to zero.
  13. Externet

    Replace CCFL backlight with LED strip

    Done that; to another brand. The important part is dimensional fitting. The LED strip must fit in the removed CCFL groove without chance for short-circuiting traces. The directionality of the light emission should be taken in account for proper illumination. Some convenient strips are...
  14. Externet

    Suggestion for right selection of ultrasonic transducers.

    I would say the intimate contact mounting with no air gaps is key. Many sites to explore; just a few : ----> http://www.d-flow.com/ ----> http://www.omega.com/section/doppler-transit-time-ultrasonics.html ----> https://www.pulsar-pm.com/product-types/transducers.aspx ---->...
  15. Externet

    4 awg lug connector for 5/32" terminal?

    At the hardware/plumbing store or in the dumpster of an airconditioning servicing place. Perhaps behind an old refrigerator with a defunct ice maker.
  16. Externet

    4 awg lug connector for 5/32" terminal?

    You did ? If not, make them. A copper tubing section that accepts 4AWG soldered/crimped in it; flattened and drilled. Like ----> http://www.brassanchors.co.in/wp-content/uploads/2015/04/Single-hole-Terminals.jpg There is other types ---->...
  17. Externet

    relay sticking

    Unscrew the heat lamp and check if the relay contacts still get consistently stuck and need to tap to disengage when power is removed. If still sticks, the mechanism of the relay is binding. Means repair, lubricate, add tension to the return spring or replace the relay. If does not, there is...
  18. Externet

    Dryer's heat fluctuates?

    Just hook a clamp current meter to the dryer and confirm the consumption is steady or not. There may be a poor or intermittent heater element contact.
  19. Externet

    Cooling Fan blowing the fuse

    Connect your fan with the specified fuse, and when on, sense by hands which terminal/contact/splice to the fuse gets hot. If such hot point is near the fuse, it will conduct heat to the fuse causing it to melt before desired.
  20. Externet

    How to power 2 computers fans with cellphone chargers

    Better use 5V fans.
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