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  1. KrisBlueNZ

    need help with simple 3v to 34v transistor relay/switch

    RCREG always "has data", in that if you read it, you will get a byte value. RCIF tells you whether it has NEW UNREAD data. Whenever you detect RCIF set, you read RCREG to get the new data byte; this also resets RCIF. It shouldn't be possible to get into a state where RCREG "has NEW data" but...
  2. KrisBlueNZ

    How to address a moderator

    Hey! I wanna see it too!
  3. KrisBlueNZ

    A Special Place In Hell For Yahoo

    I use gmail, accessed using imap from Thunderbird. I very seldom see any spam, and my gmail address is all over the web. It seems to work pretty well actually.
  4. KrisBlueNZ

    Comparator for anemometer

    Well, duke37 said that the NE5534 is specified with a minimum operating voltage of 6V. What's the effect of running it at 5V? I don't know. It could work perfectly, just slower, or it could fail to work at all. NE5534s from some manufacturers, or some batches, could work, and others could fail...
  5. KrisBlueNZ

    need help with simple 3v to 34v transistor relay/switch

    I know that feeling! I'll PM you my email address. Please feel free to ask me anything. I would be happy to help. This sort of stuff was my job for 20 years! Yes, you have to service the USART receiver before the next complete byte is received, otherwise you lose data. At 9600 bps asynchronous...
  6. KrisBlueNZ

    need help with simple 3v to 34v transistor relay/switch

    That's great! Yes, a state machine is probably the best way to implement your USART interrupt handler on a small micro like the PIC. It's messy and you have to be careful, but it gets you a nice self-contained process. You have to be careful with variable ownership though, especially since...
  7. KrisBlueNZ

    Unipolar to bipolar

    If you want to feed the primary of a step-up transformer with a bipolar square wave, the best way is to drive it using an H-bridge. This is an arrangement of four switching devices (transistors or MOSFETs), like two amplifier output stages, with the load connected between them, forming an "H"...
  8. KrisBlueNZ

    Transducers in Musical Cards

    Similar products: http://www.digikey.com/product-search/en/audio-products/buzzer-elements-piezo-benders/721679
  9. KrisBlueNZ

    Unipolar to bipolar

    Hi and welcome to the Electronics Point forums :-) Note: It's not normal to connect IC pins together by drawing wires on top of the IC symbol. Besides, it looks a bit like a swastika on your 555, and the 555 was designed by a Swiss guy, not a German! If you want a bipolar output, there are two...
  10. KrisBlueNZ

    programming about motor..

    What microcontroller are you using? Google the relevant words. There are many tutorials and project plans out there that will tell you how to do this. Also, look in the forums for the microcontroller you want to use.
  11. KrisBlueNZ

    Requires 70 Volts AC

    You're right that a load will only draw as much current as it needs. So you could in fact power a 12V, 2W light bulb (which draws 0.167 amps) from a transformer that's rated to supply up to 1000 amps! OTOH, many voltage sources have poor load regulation, so they may provide more voltage if the...
  12. KrisBlueNZ

    I Think I Missed The Memo

    LOL Chris :-) I assume you're talking about Mr. "anwaypasible" and his thread https://www.electronicspoint.com/power-saving-speculation-t261538.html. Yes I had similar feelings. His posts are like a stream of consciousness, without the consciousness part. I think Steve summed it up pretty well...
  13. KrisBlueNZ

    Capacitor Value issues (simple)

    That doesn't make sense. Try it again and make sure both probes are making good contact both ways round.
  14. KrisBlueNZ

    SPDT 5-Pin Relay

    Hi James, and welcome to the Electronics Point forums :-) The TE Connectivity V23079 relay series has all pins on a 0.1" grid and is available in a good range of voltages and configurations. And it's one of the cheapest available from Digikey...
  15. KrisBlueNZ

    Requires 70 Volts AC

    How much power (or current) do you need? Where are you located? (There's a place for this in your profile settings. It can be helpful to other users.)
  16. KrisBlueNZ

    Another circuit to analyse (MALAXOR speed variator)

    I agree, that "correction" still isn't right. There's no DC path to the top of the relay coil. You will save time in the long run if you do what I suggested. Take photos of both sides, and use an image editor to mirror the bottom, and rescale and align them. Read my earlier post. If you don't...
  17. KrisBlueNZ

    Capacitor Value issues (simple)

    It's polarised? Huh?
  18. KrisBlueNZ

    Another circuit to analyse (MALAXOR speed variator)

    The triac switches ON at a specific point in each half-cycle of the AC mains waveform. This is called phase angle control. Read up on incandescent lamp dimmers to understand how it works. The other components are (mostly) to control the triac so that it switches on at the right time.
  19. KrisBlueNZ

    MOSFET power dissipation definition?

    You're welcome.
  20. KrisBlueNZ

    Help with "Data switch"

    Actually, reading back through this thread, it looks like you had already found most of the design by yourself! But you're welcome anyway :-)
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