Search results

Search Forums New Posts
  1. CDRIVE

    Motor control diy

    How cool would it be to adapt current sens to one of these? https://www.sparkfun.com/products/9457 https://www.sparkfun.com/products/9107 This one is for serious work and has soft start too! https://www.sparkfun.com/products/9668 They all have electronic braking.
  2. CDRIVE

    Motor control diy

    Isaac finally moved on. Three days of him! I thought he'd never leave!! If he's heading anyone's way you better make sure your bilge pumps are working! If he visits a drought state he's gonna fix that right quick. Kris, I suggested PWM because I figured if MasterArcher went with a current...
  3. CDRIVE

    Valve (tube) amplifier schematic help

    I don't believe it was ever intended to be powered off a 9V battery. They're feeble! Regarding the 12AX7 being used in this circuit... My simulations indicate that it would plug right in with no change in components. It produced a voltage gain 10 times higher than the 12AU7. This doesn't...
  4. CDRIVE

    Valve (tube) amplifier schematic help

    Sounds logical to me. You have nothing to loose. Heck, you may find it works fine with no perceptible noise. Chris
  5. CDRIVE

    VHF booster

    For the rest of the planet they were superseded by silicon by 1970. I can't find a data sheet for your transistor and I'm not surprised. It's difficult to design around a transistor that you have no data for. Your transistor is a child of the Iron curtain era, which is not merely ancient history...
  6. CDRIVE

    VHF booster

    A Germanium! Good grief! Actually, whether, Germanium, Silicon, BJT, FET or Vacuum Tube, that's not an RF amplifier by any definition.
  7. CDRIVE

    VHF booster

    Yes, you're absolutely correct. My apologies. Chris
  8. CDRIVE

    ASAP HELP.. guitar preamp

    I believe the impedance of PC audio inputs fall in the range of 10KΩ. That amplifier is designed to drive impedances closer to 100KΩ. I was told by Kris that 100KΩ is typical on guitar power amps, which is what this was designed to drive. Chris
  9. CDRIVE

    PWM Online Battery Charger

    Judging by this statement your battery is being used for some sort of off grid alternate power. like wind or solar cell; though we shouldn't have to be guessing. Lead acid batteries are probably the most forgiving of batteries. They handle trickle charge and brute force (high current) nearly...
  10. CDRIVE

    Motor control diy

    I need to sleep on this because I can't think straight with this storm scaring the crap out of me. It's making me nervous as a hatter! :eek: Chris
  11. CDRIVE

    PWM Online Battery Charger

    Are you sure you're not describing a 'Switch Mode' power supply? I've never seen a PWM power supply. Unless this is a high amperage lead acid battery, as ElectroBrains mentioned, I don't think you need a 15A charger, though I realize that you didn't say you did. Always post as much pertinent...
  12. CDRIVE

    Motor control diy

    I don't remember if masterarcher mentioned where he located but I think the home centers and hardware stores still stock 18AWG & 16AWG zip cord. Yeah, that what we call it. Probably because it looks like a zipper! ;) Here's a brain teaser but totally insignificant to this thread.. Anyone...
  13. CDRIVE

    Valve (tube) amplifier schematic help

    solidis, I forgot to mention that a good brad point drill works well on acrylic. As always the work should be backed with a flush waste block. Chris
  14. CDRIVE

    Valve (tube) amplifier schematic help

    Kris, if that supply gives him noise issues I gave him this earlier. It is probably a better choice than the switch mode. Yes, it's going to supply a B+ of about 17V but I don't think that will greatly change the characteristics he looking for. I would have used a 6V transformer or 12VCT but I...
  15. CDRIVE

    Valve (tube) amplifier schematic help

    Just for the record, it's replies like this that gave me no clue that you may not understand the information and the schematics I've given you. It simply doesn't sound like an electronics nube at all. ... Really! :confused: Now, moving on to the switch mode supply you just ordered. They don't...
  16. CDRIVE

    Valve (tube) amplifier schematic help

    Actually, I did but probably not sufficiently and clearly enough for a nube. https://www.electronicspoint.com/valve-tube-amplifier-schematic-help-t251475p5.html#post1488128 Chris
  17. CDRIVE

    Valve (tube) amplifier schematic help

    Do Cows fart? :rolleyes: Of course I'd like to see it! ;)
  18. CDRIVE

    Valve (tube) amplifier schematic help

    You're scaring me. The darn thing cost only $1.25!! http://www.mpja.com/prodinfo.asp?number=15447+CB
  19. CDRIVE

    Valve (tube) amplifier schematic help

    Here, it's perfect. http://www.mpja.com/9V-111A-Desktop-Supply-Fairway/productinfo/17722+PS/ The mains power cord is sold separately. Chris
  20. CDRIVE

    Valve (tube) amplifier schematic help

    As indicated on the schematic B+ is the Plate Supply. It gets connected to the 9V supply line on the amplifier schematic. Earlier I suggested a wallwart but you wanted to build your own power supply. Well, this is it and it's quite basic. If it's too complicated how do you intend to build...
Top