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  1. CDRIVE

    uln2003 data sheet question.

    That Kitty is absolutely adorable! No illusions though. In about 6 months time it would eat my face! :D Chris
  2. CDRIVE

    555 timer reverse polarity circuit

    Oh, you of such little faith. I'm sure it fixes erectile dysfunction too! :rolleyes: Chris
  3. CDRIVE

    Ohm's Law or not Ohm's Law... That is the question

    Sure they do. For BJT's it's the "Collector Resistor". It doesn't matter if we're talking Tubes, BJT's, MOSFETs, JFETs, Resistors, Light Bulbs, Inductors, Capacitors or even Wire. All components in an electronics circuit are governed by Ohms Law. Chris
  4. CDRIVE

    555 timer reverse polarity circuit

    That's OK, I don't answer questions via PM anyway. It's not conducive to the purpose of the forum. Thanks for filling me in on silver water though. Chris
  5. CDRIVE

    Valve (tube) amplifier schematic help

    Vacuum Tubes are inherently Hi impedance devices. As Kris explained to you earlier, they can be viewed as an object who's resistance between the Cathode and the Plate is varied by voltage changes between Cathode and the Grid. Since they operate with relatively high voltage and low current they...
  6. CDRIVE

    555 timer reverse polarity circuit

    Actually, I've never really known what the project does. I assumed it was some type of electrolysis but I'm short on the details. ;) Chris
  7. CDRIVE

    uln2003 data sheet question.

    If we're taking votes I'm in the MOSFET column too. Chris
  8. CDRIVE

    Sweat monitor using electrodes.

    (1) When we say "single ended OpAmp" we're referring to supply voltage. Some OpAmps, like the LM358, are specifically designed to operate well on a single positive supply. They will also operate on a bipolarity supply. Many OpAmps that are not spec'd for single ended usage can be used with a...
  9. CDRIVE

    Valve (tube) amplifier schematic help

    You're correct on that count. We don't use nanofarads in the US. In fact my schematics wouldn't display it as such except for the fact that when I enter .1uF Tina automatically converts it to 100nF. How the hell can a supplier be out of stock on a .1uF cap???? Regarding just hanging a bunch...
  10. CDRIVE

    Scratchbuilding an AM receiver--maybe a replica TR-1?

    A crystal set is dead simple to build. Add an OpAmp for an audio amplifier to drive 1000 ohm earphones or add an AF power amp chip and you have a viable AM radio. Chris
  11. CDRIVE

    Arcade 110v strobe flasher circuit help

    If you decide that you really want simple random flashing, here you go.
  12. CDRIVE

    uln2003 data sheet question.

    Oops my mistake. That should be Gorgo that ate Ireland but fortunately didn't damage the pubs. :D Probably short for Gorosaurus, a huge theropod in the Tyrannosaur family, though the critter depicted looked more akin to an Apatosaurus on steroids. Uh, does anyone know where the OP went? Chris
  13. CDRIVE

    Sweat monitor using electrodes.

    When you get your scope you will clearly see the noise. I'll then show you how you can reduce the noise with a length of wire connected to the inverting input of the OpAmp. BTW, the 318 is not a single ended OpAmp. Chris
  14. CDRIVE

    Arcade 110v strobe flasher circuit help

    No it's not. The code I posted is for the Picaxe 08M2, which is an 8 pin DIP. The circuit to mate with that code is as simple as the code. I would not have spent my time searching for a none uC solution to a random flasher if I had known that you'd cave at the prospect of a little work on...
  15. CDRIVE

    Multi Resonant Circuit

    Actually, the bandpass shape is dependent on the number of poles, coupling coefficient and the Q of each pole. I've worked with such bandpass stages that produced three peaks (F1 - Fc - F2) where F1 and F2 were spec'd @ -3dB min. Fr, Coupling and Q were played with until we got virtually a flat...
  16. CDRIVE

    uln2003 data sheet question.

    Take offense? Heck no. I too think it would be fun to have a contest. I'm semi retired but if I win I'll modify my all my company documents to include "& Psychic Medium". :p Chris Oh, I almost forgot.. I'm a big fan of old 50's - 60's vintage Si-Fi. Did you know that the Brits made a movie...
  17. CDRIVE

    555 timer reverse polarity circuit

    Electrolytics have a tolerance of +- 20%, so I wouldn't loose sleep over it. Yours is not a critical timing sequence anyway. I don't think it will matter much if the timing sequence is 1min or 2min as long as each Pos & Neg cycle is about the same. Keep in mind that the first couple of timing...
  18. CDRIVE

    Arcade 110v strobe flasher circuit help

    Check to see if the Arduino has a "Randomize" command, the Picaxe does and the code would look like this and the circuit is very basic. main: ' note random is repeatedly called within the loop if pinC.1 =1 then 'strobe switched on random w0 let pinsB = b1 ' put random byte...
  19. CDRIVE

    Sweat monitor using electrodes.

    OK, it took me a bit of time to figure out what's going on in your schematic because you said the LED is lit but dims with the beat of your heart. The way your amp is wired the LED should be off and turn on with each beat. I believe the reason it's lit is do to noise. The human body is like...
  20. CDRIVE

    uln2003 data sheet question.

    Ah, but there's the big ? Does anyone really know what the question is? I'm just going through the motions of that 50% I mentioned. :D Chris
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