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  1. CDRIVE

    LDR circuit ( Application of transistor as switch)

    Here, but as you can see with a little field expedience and red neck engineering you can make your own test points. http://www.ebay.com/itm/200-Keystone-Compact-Style-Test-Points-Choice-of-Colors-/190668058158?pt=LH_DefaultDomain_0&hash=item2c64b3ae2e
  2. CDRIVE

    H-Bridge issues at low load

    An H-Bridge is not a linear device. It's either ON FWD - OFF - ON REV. It's not intended to provide speed control. Speed is controlled with PWM to the base inputs.
  3. CDRIVE

    LDR circuit ( Application of transistor as switch)

    Those Jacks are intended for through hole mounting. They're not intended for PCB mounting. They're used on panels or on an enclosure box. Holes are drilled in the box or panel with a diameter that provides a tight press fit. Then connection is made via wire soldered to the turret ends. If...
  4. CDRIVE

    Simple circuit, Need help

    Before I suggest or draw anything I don't see how 1 & 2 can be true unless the output is being loaded by the input to your graphics unit. What's the input impedance of the unit?
  5. CDRIVE

    Power MOSFET as switch

    Forget the Zener Diode or any other diode your using. IMHO MOSFETS were designed to provide an extremely high input impedance between the Gate and the Source. IE, their great attribute is requiring insignificant 'power' (E x I) to drive the Gate. Sticking heavy loads on the Gate defeats this...
  6. CDRIVE

    Getting my head around resistance

    Like John I'm not sure what you're asking either but I suspect you might be asking about power transfer as it applies to load & source resistance or impedance. Take a look at the attachment and let us know if this is what your questioning. Note that I used the term "Impedance" because 'Maximum...
  7. CDRIVE

    Is high resistance good or bad in an alternator?

    Yes, 20,3 Ohm's is high. On this side of the pond .3mm means little to me as we work with AWG (American Wire Gage). My guess is your wire gage is too high, which translates to wire dia too small.
  8. CDRIVE

    LDR circuit ( Application of transistor as switch)

    You're welcome. ;)
  9. CDRIVE

    MOSFET IRF540A circuit.

    Yup, that would certainly explain the results of your last test. OK, this confirms that anything I design will have to be on the high side. Thanks Chris
  10. CDRIVE

    LDR circuit ( Application of transistor as switch)

    Why did I do this? :rolleyes: Here.. http://www.digikey.com/product-search/en/test-and-measurement/test-points/2294346?k=meter%20jack http://www.surplussales.com/Equipment/TestEquipment/TestEquip-18.html http://www.primedistributing.com/advancedandregtestpointpins.aspx...
  11. CDRIVE

    LDR circuit ( Application of transistor as switch)

    The gain of your transistor is extremely high. A 1K base resistor will have minuscule adverse effect. Regarding the Pin Jacks that you PM'd me about... Did you search Digikey? I don't like doing leg work.
  12. CDRIVE

    H-Bridge issues at low load

    I drew this for a farmer some time ago. The relevant part of this circuit, as it pertains to you and H-Bridges, is the transistor configuration. As you can see, they are configured as Common Emitters. Common Collectors (Emitter Followers) can't approach their efficiency as a switching amplifier...
  13. CDRIVE

    MOSFET IRF540A circuit.

    No, I wasn't. Lift the - IN (black) & - OUT (green) conductors and measure with an Ohmmeter. I suspect they're common to each other. Chris
  14. CDRIVE

    H-Bridge issues at low load

    I've seen H-Bridges designed like this before but they will not perform well because they're configured as Emitter Followers for your NPNs & PNPs. In this configuration your base voltages have to be higher than the motor voltage. Worst yet, you can't saturate the transistors, which will make...
  15. CDRIVE

    LDR circuit ( Application of transistor as switch)

    I don't know what your resources are in Malaysia but Digikey will carry the Pin Jacks that I mentioned.
  16. CDRIVE

    LDR circuit ( Application of transistor as switch)

    Looks like we doubled.
  17. CDRIVE

    LDR circuit ( Application of transistor as switch)

    Maybe they're not that common any longer but I'm sure they're still available. I'm speaking of Probe Jacks, also called Pin Jacks. Your DMM probes plug directly into them. Also, have you considered placing a 1K in series with the base and measuring the voltage drop instead of current? This way...
  18. CDRIVE

    Flasher circuit negative switching

    So, you're saying that those values are correct? EEK! :eek:
  19. CDRIVE

    notch rf filter

    Transmission Line theory and design is an extensive subset of electronics theory. The ITT Radio Engineer Bible devotes a very large chapter to it alone. You can find lengthy text books devoted to nothing but Transmission Lines. A properly designed coaxial transmission line should not radiate...
  20. CDRIVE

    Voltage Regulator

    Probably a typo. 15 to 18uF maybe?
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