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  1. Minder

    Component identification on Landscape Lighting Transformer

    Looks like a common mode choke/suppresor. M.
  2. Minder

    Thinking about opening an Electronic store: still worth it ?

    As another Canadian, for me it is not really worth it, unless an extreme emergency, I have two electronic stores here, although I hear one is closing up. That may tell you something. I can get virtually all I want from Digikey US next day air, no import duties etc, for the $8.00 P/P for air...
  3. Minder

    Need Electronics projects for 8 year old

    I agree with BobK , initially I would get him involved in basic non-electronic problems to learn the basics involving resistor, capacitor, maybe simple inductors or a small DC motor etc. I would think a micro is throwing him the deep end, if interested in simple electronics then there are...
  4. Minder

    Help identifying a resistor

    Could be 1.5meg. M.
  5. Minder

    switching a relay - but on second switch. ( if that makes sense? )

    Also using the arrangement you mention, the relay will just pulse for the sw sense duration. if this is what is needed. M.
  6. Minder

    switching a relay - but on second switch. ( if that makes sense? )

    There are special one direction limit switches if you can use them, but they could be pricey unless sourced on ebay. Another alternative is a regular limit and make your own unidirectional striker. M.
  7. Minder

    Need advise - Screwed up on my PCB - Need replacement part

    The IC sources so it should work and it does not include reverse diodes which you don't need. M.
  8. Minder

    Need advise - Screwed up on my PCB - Need replacement part

    Simple, cut the trace for pin 9, you do not need it with LED's as a load, only inductive loads. Pin 9 is just reversed biased diodes. Edit: oops I see you mean you did not source the lED's from +ve M.
  9. Minder

    It came to me in a dream

    Life getting a little slow in Wales these days?:p M.
  10. Minder

    Impedance

    What I suggest is before going on to Transistors and IC's etc is to get the basics down first and this usually entails the three R,C,L and the effects when used in conjunction with DC and AC power. These are the three basic components you are going to see in just about every circuit afterwards. M.
  11. Minder

    Why the resistor across the positive to collector?

    Would I do that to a Welshman?:) M.
  12. Minder

    Why the resistor across the positive to collector?

    If in doubt Google, Google, Google.!! Back Electro Motive Force. An inductance when powered creates a magnetic field, when the voltage goes to zero, the field collapses and induces an high voltage in the opposite polarity to the one applied. Think coil on your car. How does it get 20kv from 12v.? M.
  13. Minder

    Impedance

    In the absence of any text books, Let Google be your friend, the basic three are resistance , capacitance, inductance. Bone up on these three and their characteristics in AC & DC application. M.
  14. Minder

    Why the resistor across the positive to collector?

    Transducer: a device for converting a physical entity into an electrical signal, i.e. thermocouple, hall sensor, Light dependant resistor, etc. Your ear buds or head phones are transducers in reverse of these. The diode on output is across any inductive device in order to supress the BEMF that...
  15. Minder

    Why the resistor across the positive to collector?

    Another example, Many transducers are supplied with open collector output, and if they are connected to something such as a μprocessor that has high impedance input, then a pull up resistor is required. M.
  16. Minder

    Why the resistor across the positive to collector?

    I believe you mean a resistor from positive to collector, If a NPN this will connect the transistor to positive and provide a load for the collector in order for the E-C to conduct. Often a 'pull up' resistor is needed where the load the transistor is connected to cannot provide this current...
  17. Minder

    Temporary magnetic switch?

    Have you looked at small prox sensors such as Honeywell SS400 series? M.
  18. Minder

    Water Pump Reference or S/N

    The amount of apparent poles, It looks a lot like a BLDC motor to me, if so it would need a min of 3 conductors if the controller is outboard. Used in everything now from PC fans to washing machines and HVAC blower fans. http://www.directdrivemotors.com/ M.
  19. Minder

    A lot of old electronics (NiB), and very little knowledge about it.

    Resolvers on Ebay are posted for $100++. M.
  20. Minder

    Would like some advice about my motor speed control circuit.

    The 555 is only 8 pin. The IRF520 has half the on resistance if you haven't picked it up yet. M.
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