Search results

Search Forums New Posts
  1. CDRIVE

    Problems with circuit

    We speak the international language of "Schematic". Post yours so we can communicate.;) Chris
  2. CDRIVE

    Voltage Protection from car battery

    There's a reason that shunt regulators were never popular for anything other than low current requirements. They're wasteful by their very nature. Chris
  3. CDRIVE

    diode for collapsing magnetic field

    From the outset I've never bit the BEMF hook of this thread. I'm less convinced now than ever. I don't think that all the diodes in the world or MOVs will cure your problem. If we knew that your pump was a cheap plug in emergency pump I don't think this thread would have approached this length...
  4. CDRIVE

    Chemetron wirefeeder - trying to salvage dc motor speed control

    Glad to hear that. It's always nice when a plan comes together. Many of us can spend copious amounts of time on a topic and never know if the OP ever used the information given or constructed the circuit drawn. So, it's always rewarding to hear back from the OP. I do have a question though...
  5. CDRIVE

    Voltage Protection from car battery

    Kris, those are impressive regulators. Chris
  6. CDRIVE

    Voltage Protection from car battery

    The concept is OK and not unorthodox but this one is under rated for your needs. You'll want a model that's not being pushed to its maximum limits. Before I'd spend any money I'd investigate whether your monitor would be hurt with a 14V supply. Chris
  7. CDRIVE

    2 speakers 1 variable resistor

    Are you referring to a stereo speaker or earphone jack? Chris
  8. CDRIVE

    FM Transmitter aka Spy Bug

    New definition of "privacy": An archaic concept once thought sacred by early man. Chris
  9. CDRIVE

    LED strobe circuit needs more current

    It would appear that author's desire to keep the component count down has left this circuit with no current limiting at all. Not for the LED, collector or base currents. Things don't get much cheaper than resistors! :eek: Chris
  10. CDRIVE

    LED strobe circuit needs more current

    Well I don't know what adds up to 25 +?. I like to guess what people are building. Is this a bicycle flasher? Chris
  11. CDRIVE

    LED strobe circuit needs more current

    The component count within a chip is rather irrelevant. The 555 has 8 pins. That's all you have to deal with. It wouldn't matter if there were 10,000 in there. Chris
  12. CDRIVE

    Help with time delay relay circuit

    Yes, have you ever considered that what we do here would put the average instructor in thermal meltdown? They usually have all their students studying the same thing at any given time. We multitask!;) Chris
  13. CDRIVE

    LED strobe circuit needs more current

    If there's a "C" in the part number then it's CMOS. There is a trade off for the lower voltage operation though. You can't drive high current LEDs directly from the CMOS models. You will need a driver transistor. If your Darlingtons are power transistors they will work. A better choice would be...
  14. CDRIVE

    diode for collapsing magnetic field

    This is a long thread so forgive me if I've missed it. Has the question been asked of what gauge wire was used for the motor circuit and the relay coil circuit? Have we asked how long these runs are? If either circuit is undersized it's going to cause problems. Photos would be useful. Chris
  15. CDRIVE

    diode for collapsing magnetic field

    Electrician, I like your in the field approach to diagnostic troubleshooting. I don't see myself approaching this any differently. By the way, earlier in this thread Blank Stare said he also fried a tractor starter solenoid on this pump. It's a bit hard to dismiss this. Chris
  16. CDRIVE

    LED strobe circuit needs more current

    There's more than a single model of the 555. Did you read Harald's post? Chris
  17. CDRIVE

    Home Made Osciloscope

    Then you're good to go. Even if you had only USB you would still be OK. Just about any USB/Serial dongle that supports RS232 "Break Mode" will work. Today, I think that's all of them. The model that Picaxe sells is best though, as it's completely molded into the dongle with USB plug on the PC...
  18. CDRIVE

    diode for collapsing magnetic field

    Yes, this indicates welded closed contacts because one contact is supplied directly from the 30A fuse.. BTW, This topic is starting to come full circle. I said at the outset that I'm not convinced that BEMF is the culprit. Electrician's posts reinforces my my suspicions that the issue is...
  19. CDRIVE

    LED strobe circuit needs more current

    The LM555 is (supply and output) TTL compatible. TTL is a 5V logic family. So, yes, it's 5V compatible. That said, batteries do drain. You'd be better off running it off >5V. Chris Edit: You all beat me to the finish line!
  20. CDRIVE

    Help with thermal switches

    I Googled it using unintuitive search criteria. ... "Thermal Switch". Who'da thunk? :rolleyes: http://www.amazon.com/s?ie=UTF8&keywords=thermal%20switch&page=1&rh=i%3Aaps%2Ck%3Athermal%20switch http://www.ebay.com/sch/i.html?_nkw=thermal+switches...
Top