Search results

Search Forums New Posts
  1. KrisBlueNZ

    Voltage regulator.. or Help the noob!

    Yes, you won't get much running time from a little PP3-type 9V battery. As you mentioned, a linear regulator like that one wastes a lot of energy, especially when you're dropping so much voltage (3V out, 6V drop - the regulator wastes twice the output power, i.e. the circuit consumes three...
  2. KrisBlueNZ

    Audio output port project

    How about: What will the motor be driving? What is the overall aim of the project? Answer in DETAIL please.
  3. KrisBlueNZ

    Simple Question for those in the electronic field.

    Where would you say the sweet spot is? The best value for money, with the important features that you or I would want? How important are number of channels, buffer size, logic analyser functions, advanced triggering, etc? Yes, likewise. I would be very lucky to find any decent digital scopes...
  4. KrisBlueNZ

    Compelety stuck, on what is the type of power lead I need

    About eight years ago I had an external hard drive enclosure with a 4-pin Mini-DIN socket that looked a bit like the one in the photo. The power supply provided separate +12V and +5V rails. Every one I've seen since then has a 12V-only power supply with the usual cylindrical DC plug, and...
  5. KrisBlueNZ

    Simple Question for those in the electronic field.

    Wouldn't there be some companies that would be upgrading their test equipment every few years, that would be selling off reasonably recent scopes?
  6. KrisBlueNZ

    Simple Question for those in the electronic field.

    I agree with Adam. It really depends on what you need to do. In my last job, for 20 years, I used an analogue 2-channel Hitachi scope, and I liked it a lot. The most technologically advanced feature it had was delayed trigger, and I very seldom even used that! Of course you have to understand...
  7. KrisBlueNZ

    power supply

    OK. You must have learnt how to do the calculations, otherwise your tutor wouldn't have asked you to answer this question. We don't just write up a full answer for you. That might help you answer the question, but it wouldn't help you learn, which is what you want to do, right? Show us what...
  8. KrisBlueNZ

    power supply

    His post says an input voltage of "100 Vpp AC". I'm not sure what you're saying. Do you mean that that's the input TO the transformer, instead of the secondary voltage? That just occurred to me now, on re-reading the post. In that case, he needs to specify the turns ratio of the transformer...
  9. KrisBlueNZ

    Compelety stuck, on what is the type of power lead I need

    She chucked "the lead" in the bin... what exactly did she throw away? Did it include a mains lead, a box, and another lead that plugged into the external hard drive box? Is there a manufacturer name and/or a model name on the hard drive box? Do you want to continue to use that hard drive or...
  10. KrisBlueNZ

    Is there a liquid conductor out there, or that I can make?

    Have you considered a three-axis G sensor? If you're monitoring the position of a single object, you'll only need one of them, and some processing to detect the angles you're interested in. Check out some links...
  11. KrisBlueNZ

    Bypass standby switch

    Good one James :-)
  12. KrisBlueNZ

    Compelety stuck, on what is the type of power lead I need

    Upload a photo of the sticker on the adapter. You may need to know what voltages (e.g. 12V and 5V) it provides, and what current it can supply on each rail. What do you mean by "broke" the cable? Show us a photo of the break.
  13. KrisBlueNZ

    power supply

    No you didn't. Don't lie to us; it's not a good look. But I will try to help anyway. The question specifies a transformer with an output of "100 Vpp AC". This should be written "100V p-p". Do you know what that means? If you feed AC at 100V p-p into a full-wave bridge rectifier, what DC...
  14. KrisBlueNZ

    Bypass standby switch

    Yes and yes. I've outlined, in red, the copper area (lighter green colour) to show how the bottom left circled point connects to the top right circled point.
  15. KrisBlueNZ

    Next/previous switching a multiplexer

    I'm not sure about the MIDI connector pin usage. Also, I don't know whether a MIDI cable connects 4-4 and 5-5, or maybe 4-5 and 5-4. And I don't know about pin 2, but I would expect the cable would connect the shield (if one is used) at both ends, because MIDI cables are reversible, and you want...
  16. KrisBlueNZ

    Bypass standby switch

    Yes, 0.12 mm would be fine. It doesn't need to carry much current. And a cheap 30W soldering iron, and standard tin-lead solder about 0.8 mm diameter would be good. You can connect the wire straight across the two connected switch terminals, with a wire in position A, or position B, which is...
  17. KrisBlueNZ

    Laser Driver Troubleshooting?

    OK. It looks like you have the right layout. Let's see what happens when you replace the fuse.
  18. KrisBlueNZ

    Wireless trigger for LEDs and buzzers

    Cool :-)
  19. KrisBlueNZ

    Wireless trigger for LEDs and buzzers

    No. Comparing the byte value to a constant (in this case, 127) only works for isolating the top bit. Because if the top bit is 1, the byte value will be 128 or more; if the top bit is 0, the byte value will be 127 or less. A more general way to isolate any bit, which you can use in that...
  20. KrisBlueNZ

    Laser Driver Troubleshooting?

    It looks OK as far as I can tell. What transistors are you using? Your layout assumes the wires are C,B,E from left to right, looking at the flat face with the leads pointing downwards. This matches the European pinout that's used with BC547 and similar. The original diagram specifies a BD139...
Top