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  1. KrisBlueNZ

    Telephone cord plug replacement

    Yes, you can replace a standard modular plug if you're careful. I've done it a few times. I don't like the eHow advice. You don't need the crimping tool; these are expensive! You just need a bench vise, or if you don't have that, you can probably make a jig for it. Here's what I have done. 1...
  2. KrisBlueNZ

    Can I connect GNDs?

    You could do that. You would just be connecting the two bottom halves of the bridge rectifiers in parallel. Connecting diodes in parallel isn't a good idea unless they are closely matched and held at the same temperature. That's because one of them will have a slightly lower forward voltage...
  3. KrisBlueNZ

    Safe? Bedini SSG 12v Lead Acid Battery Charger Desulfator

    Yes, so do a lot of people. And a lot of other people don't! I think you would really have to do a proper test to know for sure. Lithium batteries don't use sulphuric acid do they?!
  4. KrisBlueNZ

    Transmit and receive parallel data through radio link

    Yep, that's a good one Bob. Looks like it will do what he wants. I think 6 bits is enough. BTW do you know whether those "Princeton Technology" devices are actually microcontrollers in disguise? I don't recognise the pinout. I'm interested to know whether it's a custom device or just a...
  5. KrisBlueNZ

    RGB LED Control

    No, I don't think the LM3914 will be useful at all. Here's what you need to do. You need to show us a graph that specifies how the intensity for each of the colours (red, green and blue) changes as the control potentiometer is varied from one end to the other. Something like this: I have no...
  6. KrisBlueNZ

    Looking at an arduino

    I assumed he was referring to quality specs, not functional specs. That's the usual difference between an original and a clone. Of course, if it doesn't function as an Arduino it shouldn't be described as one.
  7. KrisBlueNZ

    Transmit and receive parallel data through radio link

    Me too. But he doesn't want to use micros. And I think the information is non-critical and brief disturbances are acceptable. Is that right Lavaguava?
  8. KrisBlueNZ

    RGB LED Control

    The problem is not the circuit; it's defining what brightness you want from each of three colours, given a single-dimension control source. I don't understand. I thought he wants to control the red, green and blue intensities of a single RGB LED using a single potentiometer.
  9. KrisBlueNZ

    Chicken Coop Door Opener

    Yes. Except it only has one limit switch, at one end of the door travel. Currently it's the fully open end, but I think he may want to change it to the fully closed end, since that's the important one for the safety of the chooks. Yes, exactly. And there's a maximum retry lockout.
  10. KrisBlueNZ

    P2 Audio Switcher

    I would also have both connected at the same time. When you want to use the speakers, take your headphones off, and select that input on the stereo or turn the volume up. When you want to use the headphones, turn the stereo volume down or select an unused input, and put the headphones on.
  11. KrisBlueNZ

    Please help me identify this component

    It could be an R-2R resistor network. Have a look at http://www.digikey.com/product-detail/en/4610X-R2R-103LF/4610X-R2R-103LF-ND/3787967 and see whether this matches what you have there. If not, show us a close-up of the markings - we may be able to identify the manufacturer. Edit: Oh, and...
  12. KrisBlueNZ

    P2 Audio Switcher

    What exactly do you want to do? You want a two-position switch, right? What do you want to happen in each position? Do you want to send your computer's audio output to either the line input on your stereo or your headphones? It may be as simple as a double-pole or four-pole switch (rotary...
  13. KrisBlueNZ

    Treadmill boards

    Hi there and welcome to Electronics Point :-) Once you have some specific information on at least one manufacturer and model, you could create a user-submitted resource on this subject. Photos would be needed. There have been several threads on treadmills here in the past which will contain...
  14. KrisBlueNZ

    RGB LED Control

    You could probably use three variable current sources, but how would you define the mapping between a single-dimension control (a rotary or slider potentiometer) and three independent quantities? When you use a colour selector on your PC, there are three separate sliders; one for red, one for...
  15. KrisBlueNZ

    Chicken Coop Door Opener

    You're welcome Dan :-) No, the relay always pulses ON for one second. This tells the garage door controller to start moving the door to the opposite state. The garage door controller latches this command and moves the door until it reaches the end of its travel. The PICAXE control code expects...
  16. KrisBlueNZ

    Transmit and receive parallel data through radio link

    Yes, likewise. The information you want to transmit is digital, right? Seven digital signals?
  17. KrisBlueNZ

    Safe? Bedini SSG 12v Lead Acid Battery Charger Desulfator

    That "design" is not as dangerous as a direct mains-powered circuit, but it isn't going to do anything useful. It may charge a small battery very slowly. The guy doesn't understand basic physics. He is talking about high voltage being fed into the battery at low current. Because he can draw a...
  18. KrisBlueNZ

    Boost converter 12V to 36V (25 mA load) using 555

    Possibly, but CDI needs a lot more than a few mA...
  19. KrisBlueNZ

    [free energy] is there hidden power in plain sight?

    Sure, I understand. However, the whole idea that it might be possible to get more energy out of a circuit or device than the amount of energy you put in, which is what I think you are suggesting, is impossible. Many people have claimed to be able to do it, over the centuries, and they have all...
  20. KrisBlueNZ

    How to increase current and maintain a constant voltage ??

    Current is drawn from a power supply. The 650 mA current rating of your 12V charger is the maximum current it is designed to be able to supply. If the circuit or device that you are powering only draws 45~100 mA, then only 45~100 mA will flow. This is way under the limit for that power supply...
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