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  1. K

    Help with finding a resistor to drop 220v to 110v

    Yup! Changed it. In the middle of a cold. Online only: http://www.radioshack.com/nte-hw382-10-1-2w-82k-ohm-2-/55049210.html#.VICpNWfZfCs But should be available from any electronics parts vendors. Where were you looking? Ken
  2. K

    Help with finding a resistor to drop 220v to 110v

    Looking at the actual DIALITE spec sheet: http://www.dialight.com/Assets/Brochures_And_Catalogs/Indication/507-xxxx-xxxx-640.pdf The internal resistor is 47KΩ, not the 4.7KΩ as shown in the Allied link. That had seemed awfully low. I have no idea where the "Current, Rating : 1200 mA" came from...
  3. K

    Replacement Power Supply Project

    Right you are!...I need more coffee...or less. ;) Ken
  4. K

    Replacement Power Supply Project

    Assuming the output is used with a center-tapped-transformer rectifier circuit, 18VAC*0.62A=11.16VA (watts) That transformer is likely too small. Ken
  5. K

    Polarities on Fuse Holder?

    Fuse holders don't have positive/negative polarity. They are placed between one side of the power source and the load. With that holder, the power source would be connected to the end terminal and the load would be connected to the side terminal. The concept is the same as with light sockets...
  6. K

    remote on/off

    Can you sketch out a block diagram of the "system". Is the 4-20mA part of the inst-amp or is it remote to it? Where is the "receiver" relative to the 18V batteries? How is the receiver powered? Ken
  7. K

    EMITTER DETECTOR SENSOR

    BHEKI, Out of curiosity, what was the purpose of resistors R3/R5/R6/R8 in your circuit? Ken
  8. K

    remote on/off

    So you have an instrumentation device, powered by a PP2 9V battery. It outputs a 9V(?)/4-20mA signal. The 4-20mA signals goes somewhere over a pair of wires? Or is this a stand alone data logger that you need to power on/off remotely. Ken
  9. K

    Connecting Li-ion cells in series

    "...3.5 V and 2800 mAp each. I soldering them in serie which would total 10.5 V and 8400 mAP. First question is the fact that the mAp is double, does it mean that the device would run twice as long?" No. It's 10.5 V/2800mA. You increased the total voltage, but the current available for the...
  10. K

    Schematic for a Crate VXF5112 Guitar Amp?

    Way late in getting back. I got the schematics. Between my vast experience with tube circuits ;) and similar amp circuits on Google Images, I had eliminated most possible problems. I was doing some scope probing with the amp on standby and I noticed that touching pins on one of the two output...
  11. K

    Servo info wanted

    There are a lot of good tutorials on servos out there. Google: how servos work Ken
  12. K

    Water Sensor Switch and Pump

    With the PICAXE in mind...I did an automatic Christmas tree stand waterer with an 08M Picaxe. http://www.picaxeforum.co.uk/showthread.php?12266-08M-Christmas-tree-watering-controller&p=98183&viewfull=1#post98183 Three stainless steel electrode sensor with an AC drive to reduce erosion. The three...
  13. K

    a few half-burned resistors in circuit. how bad is it?

    If you measure the resistances of the 47K resistors (R28,29,30,31,32) with the ICs removed, there should be no parallel resistance paths. Ken Also R33 and R34 with the address jumpers out.
  14. K

    How to increase voltage?

    TLA is Three Letter Acronym. It's a slam at people that use TLA's, as if every knew what they mean. Ken
  15. K

    Looking for (really) old construction article

    Yeah! OK, I was wrong about Popular Electronics and the 2N3055. But it was a TO-3 case. :) Ken
  16. K

    Looking for (really) old construction article

    Some archives: http://www.americanradiohistory.com/Popular-Electronics-Guide.htm http://www.americanradiohistory.com/Radio_News_Master_Page_Guide.htm http://www.americanradiohistory.com/Electronic_World_Master_Page.htm http://www.americanradiohistory.com/Radio_Electronics%20_Master_Page.htm...
  17. K

    Looking for (really) old construction article

    Wow. I remember that! Lots of 2N3055s and a rotary telephone dial as an input number/count generator. But, all my Poptronics magazines went long ago. Ken
  18. K

    Electrically controlled expandable rod

    Google: micro miniature linear servo Ken
  19. K

    looking for a transformer

    Google: miniature power transformers Lots of manufacturers Ken
  20. K

    thermopile

    From my understanding, solar panels' usable light spectrum is the visible range. That sensor is for Infrared. Ken
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