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  1. CDRIVE

    alarm door opener help

    This circuit it based on the quoted statement.
  2. CDRIVE

    Digital meter

    A Wattmeter must be able to read true power not apparent power. The electromechanical versions are called Electrodynamometers. They're constructed with a current coil and a voltage coil, with an end result of measuring true power on a reactive load. Unless there's a magic chip that I'm unaware...
  3. CDRIVE

    Rat Zapper Power Supply

    Look in the bright side. Arizona doesn't have Nutria. They get big enough to throw a saddle on! :D
  4. CDRIVE

    555 timer reverse polarity circuit

    Give this a look see and tell me if you understand it. The +12V supply for the 555 is an inexpensive wall wart. I could have added a 12V regulator and powered it off the 30V leg of your power supply but wall warts are easy to use and cheap. Besides, all of us have multiples of them that are...
  5. CDRIVE

    Digital Pot setup

    Justin, many posters are drive by's that I'd never recommend spending the cash for a good spice simulator. You're not one of them. You have a keen interest in electronics and I don't think that your motor controller or the LED head light is going to be your last project. So, yes I think it's a...
  6. CDRIVE

    555 timer reverse polarity circuit

    That would be a 555 driving a SPDT relay. I'll draw it up for ya.
  7. CDRIVE

    Common Emitter Transistor

    The problem of complete turn off in PNP high side switching arises often. Diodes and or LEDs can be used to insure that Vbe goes below the base threshold voltage. A resistor between the base and emitter can also be added to further insure collector current turn off. Since this sounds like home...
  8. CDRIVE

    Political argument (Yeah, this is going to end well)

    Funny CC, It's not out of control now? Watch the vid. You'll bust a gut! Chris
  9. CDRIVE

    Political argument (Yeah, this is going to end well)

    Steve, United States Constitution has provided for the nation's defense since its signing. In fact, it's one of the very few powers that was given the federal govt at the time. There is nothing in there that provides for police, which is a State and local matter. We are not a Democracy as...
  10. CDRIVE

    MOSFET IRF540A circuit.

    Hmmm.. Odd. Chris
  11. CDRIVE

    Chronograph for bullets

    I'm not certain how reliable the foil method will be but you're correct when you say that you didn't measure it right. ;)
  12. CDRIVE

    3 digit panel meter to read -volts

    Here's some. http://www.mpja.com/Digital-Panel-Meters/products/52/
  13. CDRIVE

    MOSFET IRF540A circuit.

    Justin, did you recently make a post but deleted it? I received an email alert but it's not here.
  14. CDRIVE

    555 timer reverse polarity circuit

    Thanks for clarifying that. Since you have a dual (+-) supply a SPDT relay will suffice. Do you want a solid state alternative? If so, it will be more complex but should last forever.
  15. CDRIVE

    Political argument (Yeah, this is going to end well)

    I'm only aware of some of the changes in Australia in my life time. Here in the U.S. it's a damn nightmare. Our downward slide began in the mid 1960's when Marxists realized they would never get a solid foot hold in the U.S. and saw the Hippie movement as an ideal petri dish to fester in. When...
  16. CDRIVE

    3 digit panel meter to read -volts

    If you use a battery then your panel meter supply is free to float above ground like a DMM. A DMM can have either probe connected to ground. Will your panel meter work if you wire it like this?
  17. CDRIVE

    3 digit panel meter to read -volts

    Geezzzzz this is one of those downright confusing topics. I think It's because some of your statements don't match the information extracted from the PDF. These are your quotes compiled from multiple post. The pdf specs the output as +- 15V Max. So what's the point? The DC input to the...
  18. CDRIVE

    3 digit panel meter to read -volts

    Thanks for posting this Steve, It clears up the PS part of this topic. Now I'm going to go back to post 1 and read it all over again. ;)
  19. CDRIVE

    3 digit panel meter to read -volts

    Post shematics of your circuit and a link to your meter. Your discriptions are frying my brain.
  20. CDRIVE

    3 digit panel meter to read -volts

    Was there an illustration? Maybe I missed it? I'm still lost. I have no clue as to what you're wanting to do. If you're wanting to increase the voltage range of the meter, a simple way is to use a voltage divider and divide by 10. But as I said, I'm confused. :confused:
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