Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by bogeyman

  1. bogeyman

    Transformer Wiring Diagram

    If there are only 2 cores (your post isn't too clear) this may be scott tranformer which can used to convert 3 phase to single phase while loading all three phases equaly, google it or try wiki.
  2. bogeyman

    Inrush Current Simulation

    The incandescent lamp will draw up to 10 times its normal running current at switch on, measure its cold resistance and compare that to its calculated running value to get a more accurate number. The construction of the lamp will affect the time it needs to warm up and gain resistance.
  3. bogeyman

    Fusing the mains

    We do use single phase 415/440v (2 of 3 phases) in the UK within machine control cabinets to power low voltage kit via transformers, usualy for lower power stuff like panel lamps and relays. This is done to accomodate delta connected power inputs which reduce the power cable count to 3 + ground.
  4. bogeyman

    weibbridge to diff pair?

    Better still use an instrumentation amp with its gain set around 1000, you only need one resistor to set its gain and maybe an r/c lowpass filter to clean up the signal a little. With luck you can power it from the excitation voltage. Lots are available from the usual semiconductor folks...
  5. bogeyman

    High Temp Thermoelectric Generator

    Try http://www.dself.dsl.pipex.com/index.htm Doug's museum of retro tech has a thermo gen section
  6. bogeyman

    Brake Lights versus Turn Signal

    In my old austin healy 100 (1954 when flashing turn indicators were a novelty on the UK roads) there was a dual relay box (one relay for each side) which took both the brake lamp and signal wires in and sorted out which feed to send to each lamp, it was a standard Lucas part. If I can find the...
  7. bogeyman

    Switching 8 parallel a.c. Contactors with one pressure switch

    Use a contact arc suppressor or RC snubber (100r + 0.1u) across the switch contacts and they wil last much longer.
  8. bogeyman

    Electromagnetic induction?

    No patents there it is just a fat magnet loose (axialy)inside a coil this forms an AC generator, the torch things have a rectifier to turn the AC to DC which charges a supercap to store some electricity. The avalible power is quite low.
  9. bogeyman

    Explosion in domestic Microwave oven

    Try reading the oven makers handbook, usualy dishware is marked as being suitable for use in such devices if its not marked so it may as you found explode or at least the glaze will tend to craze.
  10. bogeyman

    Hall effect switch

    I doubt that the switch is becoming magnetized, its more likly that inrush currents are welding the switch closed. Have a look at some reed switch makers websites for what you should avoid when using reed switches, one no no is capacitance across the switch or the switched load.
  11. bogeyman

    AutoCAD File Resources

    They usualy come from the manufacturer, if they aint got cad files dont bother using their parts.
  12. bogeyman

    Looking for a power supply that can be modulated

    My solution to this problem, (we wanted 2v of 400hz and its harmonics on top of a 28v 2A DC supply) was inject the required signal (via a capacitor) into a resistor tied to the summing junction of the psu control amp, at the end of the voltage pot on a farnell L30B bench unit. It seemed OK up to...
  13. bogeyman

    Current Mirror Application

    The mirror works by establishing a Vbe on the input transistor that will provide a collector current equal to the input current, that is to say that the Vbe developed is appropriate for that particular transistor at whatever input current is supplied, it follows that if another transistor (At...
  14. bogeyman

    Supplying Voltage to Load Cells

    A very high performance linear supply is normaly required. You may have mains bourne interference causing your error voltage. Make sure that the signal and supply pairs are well twisted and if possible use an overall screen on the load cell cable. To overcome AC mains interference an AC...
  15. bogeyman

    Parameters for using 555 Timer

    The bipolar 555 has a nasty switching characteristic it puts both the sink and source on for a few nano seconds when the output changes state this draws a horrid hefty and fast edged pulse(>500mA)from the supply which will invariably drop in response to the pulse, it is essential that very good...
See more

Part and Inventory Search

Back
Top