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  1. audioguru2

    Question on the Plants Watering Watcher circuit

    To All, What did I get myself into?: "Hey, what's that thing? For the plants? Cool, can you make me some?" Do you know how many times I have heard that in the past few days? This dumb project is becoming very popular with my friends. ;D ;D A few minor bugs: ::) 1) When carrying the project...
  2. audioguru2

    UPS Question..

    Kasamiko, As long as the original battery had the same chemistry (lead-acid) as your new bigger one, the charge circuitry won't care but it will take a longer time to fully charge. I hope that the charge circuitry doesn't have a charger timer.
  3. audioguru2

    detector prototype

    Badai, You may have a problem by using this project: An LM324 will replace the MC3403, and a 1N34A diode will work in this project.
  4. audioguru2

    knight rider led modifications????

    New, We are glad to help you. Perhaps you didn't understand the difference between your "chaser" that flashes the lights always in 1 direction, and a "knightrider" that flashes the lights back and forth. I am afraid that the chaser may cause traffic confusion since it will appear like a...
  5. audioguru2

    Question on the Plants Watering Watcher circuit

    Ante, Yea, I actually had to try out different resistors (tweaking) and exercise my solder-sucker for a change. It was because my LED current source didn't work as designed, since it was operating with only a 2V supply while powering the 1.8V LED, and didn't have much voltage remaining to...
  6. audioguru2

    Convert 0-30V 3A PSU to 5A or more

    Xenobius, I am sorry that you ordered an expensive transformer without having any technical considerations: 1) Your 30VAC, 5A winding will supply only 3.5ADC, due to its VA limitation. This project can use very-high supply voltage opamps, mentioned much earlier, and most of the recent...
  7. audioguru2

    knight rider led modifications????

    New, Your circuit is not a Knightrider, it is a simple chaser. The lights in a Knightrider go back and forth, counting forward and then reverse. This circuit is designed for an electronic relay that doesn't have a coil. The coil in a relay produces a high voltage spike that destroys ICs and...
  8. audioguru2

    knight rider led modifications????

    New, Which circuit did you build? Is it the one in our Projects Section, titled "Knightrider Lights for Model Cars", that uses a 4017 counter chip? If you connected relays without using anti-spike diodes across them, then you probably blew that chip. Besides, the 4017 doesn't have enough current...
  9. audioguru2

    Convert 0-30V 3A PSU to 5A or more

    Xenobius, What do you mean by this: I said that a 30VAC transformer voltage is too high. I said to use a 28VAC transformer. I said to use an 8A transformer. You don't need to find another circuit, this one will be fine with a few modifications that we have discussed.
  10. audioguru2

    the right resistors for the power supply?

    Ante, Only if you heat them to a very high temperature with a blow-torch!
  11. audioguru2

    NICAD Battery charger/reconditioner HELP

    Moltra, I think that you are being ripped-off for expensive battery modules that contain only 6 common AA cells. If you simply discharge the seriesed battery cells down to 6,6V, then you run a risk that the weakest cell will discharge completely, and then be charged in reverse by the stronger...
  12. audioguru2

    constant current source

    Kevin, A transistor as a current source has a small variation in its base-emitter voltage with changing current through it. This causes its "constant" current to also vary, making its peformance lousy. An opamp with its enormous gain cancels this variation. The opamp circuit works well at high...
  13. audioguru2

    the right resistors for the power supply?

    Ante, Of course, I know, but I'm just making certain that Wheelro doesn't put them all "inline" like: LED, resistor, another LED, another resistor, etc., all in series.
  14. audioguru2

    Question on the Plants Watering Watcher circuit

    Hey Guys, Last night, after watering my plants, I turned-off the lights and noticed that the LED on my slightly-modified project was very, very dim. I never looked at it in the dark before. I previously replaced the useless 100K trimpot with 220K so that the LED wouldn't indicate wet...
  15. audioguru2

    the right resistors for the power supply?

    Wheelro, Your LEDs are "cool blue" aren't they? ;D You can't use them "inline" (in series) because your 6V power supply doesn't have enough voltage. Using Ante's 150 ohm resistor in series with each puts 16.7mA through each one. Simply divide the current rating of the power supply by 16.7mA to...
  16. audioguru2

    0-30 Vdc Stabilized Power Supply

    To All, See the other post about fixing this project before simply modifying it for 5A output.
  17. audioguru2

    Convert 0-30V 3A PSU to 5A or more

    Xenobius, 1) The original circuit doesn't work with only a 24VAC, 3A transformer, similar to why I explained with your added regulator and zener. That's why there are so many complaints here and on the other post. Your engineer assumed that the original transformer is correct and simply...
  18. audioguru2

    Noise suppressor for car

    Stuee, If unplugging the RCA cables at the amps makes the noise go away, then adding audio isolation transformers to the RCA connections will also work.
  19. audioguru2

    Noise suppressor for car

    Stuee, I believe that you have a ground-loop problem that is caused by your components being grounded at different locations. It doesn't matter that the head unit is turned off, it is still grounded. To prove the ground problem, unplug the RCA cables at the amps. If the noise is gone then the...
  20. audioguru2

    was Re:Ir-remote Now is: Op Amp discussion

    Hotwaterwizard, Our project's receiver has an opamp without an input bias voltage. The receiver will probably be a lot more sensitive if pin3 is biased to half-supply with a couple of 2.2M resistors.
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