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  1. K

    With sending one pulse into a motor, does that make it move a step?

    What type of motor, voltage,current, speed? Ken
  2. K

    The smallest 240vac to 12vdc power supply

    More like 30x55x20mm. Gate threshold for the irf740 looks like 2-4VDC, so 5V might not work. Ken
  3. K

    The smallest 240vac to 12vdc power supply

    This is the typical SMPS removed from cellphone charger wall warts. I use them for PICAXE projects. 100-240VAC >5VDC/750mA Ken
  4. K

    The smallest 240vac to 12vdc power supply

    Not sure what your actual project is (It really helps to elaborate), but that is a dangerous design for a beginner. It can put the "hot" side of the line directly to your circuit common. You would also need to rectify and filter (large components) before that circuit comes into play. Unless the...
  5. K

    The smallest 240vac to 12vdc power supply

    You didn't say what your current requirement is. Ken
  6. K

    DIY High Voltage Function Generator Design

    You want a 10KHz function generator that outputs up to 70KV at up to 100mA? That's 7000W on the output. Divide that by the the battery voltage and you will see your battery current even it were 100% efficient. That's 583 amps peak for 12 battery. And driving your output at a rate 7000V/uS. And...
  7. K

    DIY High Voltage Function Generator Design

    What output current? Ken
  8. K

    inline ac polarity checker

    I think that the OP is referring to "outlet checkers". Which has nothing to do with the wiring of the AC side of power supply. For that, (s)he would have to compare the continuity of the AC wiring of the power supply to the design schematic. With no ground to reference, there is no real...
  9. K

    Modifiying timer circut for lower voltage

    The TI datasheet http://www.ti.com.cn/cn/lit/ds/symlink/lmc555.pdf spec's operating parameters down to a 1.5V supply. Ken
  10. K

    Circuit Schematic Design Software

    There is an ExpressPCB YAHOO group that has a file section where people have posted components that they have created...though not well organized. As shumifun50 stated, it's really easy to create new schematic and PCB components. Ken
  11. K

    Delayed Start Timer

    Yes, there are small 8-pin chips like PIC microcontrollers that will do that, but require programming. If you want an off-the-shelf, 12vDC timer you might look at something like this: http://www.ebay.com/itm/LCD-Digital-Power-Programmable-Timer-Switch-Time-Relay-DC-12V-16A-USA-Ship-/321127095779...
  12. K

    Delayed Start Timer

    What are you trying to switch on? What voltage/current/wattage? My first guess would be a wall-plug timer. But, more details would help. Ken
  13. K

    Rotation Switch

    Not a simple switch, but a tachometer followed by a missing pulse detector set to the desired minimum frequency/RPM. What rpm are you wanting to be the trigger point? Ken
  14. K

    What is this connector called?

    You might also want to post pictures of the disconnected connectors showing what type of contacts they have. Ken
  15. K

    Over done I think?

    Someone that didn't know how to use power busses in a simulator. ;) Ken
  16. K

    help with picaxe

    This may help: http://www.electro-tech-online.com/threads/does-a-mosfet-need-a-gate-resistor.87419/#post-682097 Ken
  17. K

    PCBExpress Help

    A quick look at the datasheet...looks like the pentawatt is just a T0-220-5 package that is already in ExpressPCB's PCB component library. You can use the LM383A schematic symbol in the Schematic Library. The pins match. Just rename it TDA2040. Ken
  18. K

    PCBExpress Help

    Yes, you can make you own components for PCBs in ExpressPCB. One of my favorite features of ExpressPCB is easily modifying or creating custom components and schematic symbols. Go to the HELP pull-down and select ExpressPCB Users Manual & Online Help... Then select Making Custom Components...
  19. K

    Program for drawing schematics?

    Anyone tried Design Spark? Ken
  20. K

    Program for drawing schematics?

    I like ExpressPCB. Ken
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