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  1. KrisBlueNZ

    and/or gates with 120 and 240 volts

    You can implement AND, NAND, OR, NOR, XOR, XNOR and inversion using relays, by connecting contacts in series (AND function) or parallel (OR function). Relays are available with 110VAC and 230VAC coils. Google relay logic and ladder logic.
  2. KrisBlueNZ

    New guy!

    Yeah, I saw it. I can't help with that one, but there are others here who probably can.
  3. KrisBlueNZ

    New guy!

    Hi there and welcome to Electronics Point :-) I hope we'll be able to help.
  4. KrisBlueNZ

    Splicing right and left channel to one earbud/headphone

    Well, microcontrollers deal with digital signals, so you can't feed the audio through a microcontroller unless you convert it to digital with an ADC (analogue-to-digital converter) then back again with a DAC (digital-to-analogue converter). This will affect the sound quality unless you use...
  5. KrisBlueNZ

    Hello, Welcome! (Introduce yourself)

    Hello, hellboy_2_88. I hope you're not here to spam us. (I guess I'm an optimist.)
  6. KrisBlueNZ

    a more simple request (was solar / relay / timer control thread)

    Actually, you can put it back in, if you can be bothered. It was stripped out when you pasted the text into your post. It's a very irritating "feature" of the XenForo system. I've reported it to Ian. There's no guarantee it will ever be fixed though.
  7. KrisBlueNZ

    Low Pass Filter design

    Is your input signal just a single frequency? In that case, a filter probably isn't the best option. One option is a frequency-to-voltage converter and a comparator with an adjustable threshold. Another option is a circuit using one or two monostables. Either of these can give a fairly accurate...
  8. KrisBlueNZ

    Bad output on DMX Splitter

    It's very unlikely to be a resistor. Check very carefully that you didn't damage any tracks when you replaced the 75176es. If not, most likely the LM339 was damaged when the 75176(es) were damaged.
  9. KrisBlueNZ

    Rain Sensor Status

    Right. Yeah, you said. Can you bring it inside and dry it with a heater?
  10. KrisBlueNZ

    Bad output on DMX Splitter

    I'd put my money on one or both of the 75176es that drive the DMX connectors. They have no protection components and could be damaged by ESD or some other kind of surge. A failed 75176 could draw excessive current from the 5V rail. That would explain why the regulator is pulling down its input...
  11. KrisBlueNZ

    Rain Sensor Status

    Right. Actually there could be an issue with the Rain-Clik - it is specified for use with 24VAC. The documentation says that you must not use it with 110VAC, but it doesn't say anything about 24V DC. And it doesn't describe the electrical characteristics of the Rain-Clik's output. I have...
  12. KrisBlueNZ

    Bug-finding

    In my (limited) experience, most of the probems in set-top box firmware show up when it's being stressed - trying to do lots of things at once - or over a period of time - for example, file system and disk space allocation bugs where the bug causes incorrect information on the disk but the...
  13. KrisBlueNZ

    Ozito 14.4V Li-On charger circuit

    Hi Ray :-) Can you add a heatsink on the transistor? And drill some small ventilation holes? There's no need for the incoming supply voltage to be as high as 32V. 24V DC should be plenty. Perhaps the adapter has a problem. Is 32V the marked output voltage on the adapter?
  14. KrisBlueNZ

    Rain Sensor Status

    LED1 will light when it's dry, and LED2 will light when it's wet. The schematic shows the relay in its un-energised state. This corresponds to an open circuit at the sensor, which corresponds to a wet condition. Yes, try jumpering the rain switch, to simulate a dry condition.
  15. KrisBlueNZ

    Rain Sensor Status

    The Rain-Clik information sheet is at http://www.hunternawadnianie.com.pl/sites/default/files/IC_RainClik_dom.pdf According to that sheet, the Rain-Clik provides a contact that is closed in dry weather, and open in wet weather. This contact can be connected to the sensor inputs on an irrigation...
  16. KrisBlueNZ

    74HC138N: IC Beginnings Chapter Two

    Yes. If you want to decode six bits to a one-of-64 output, you need eight 138s, and three inverters to generate complemented versions of the top three bits. Each 138 will only activate on the appropriate combination of its three enable inputs, so you just connect the enable inputs of each 138 to...
  17. KrisBlueNZ

    Permission to come aboard

    Hi Murat and welcome to Electronics Point :-)
  18. KrisBlueNZ

    74HC138N: IC Beginnings Chapter Two

    OK :) Don't obsess about it. "Intriguingly cryptic" and "poor communication skills" are two sides of the same coin! Cool! My sister lives in Melbourne.
  19. KrisBlueNZ

    a more simple request (was solar / relay / timer control thread)

    Sorry to be difficult... could you put arrows on the lines in the bottom section please?
  20. KrisBlueNZ

    RadioShack Electronics Learning Lab and Sensors Lab

    Yes, definitely. Experiment with the circuit to see the effect of changing component values. Ideally you should have some idea of what you're doing, or be prepared to replace the components you damage! Also, Google the circuits and components you're using, and read the information that came with...
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