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  1. CDRIVE

    Audio transformer for crystal set help

    Collin this is a milestone. You wrote a complete paragraph and it didn't contain a link to your website. Are you feeling OK? :p Cheers, Chris
  2. CDRIVE

    Audio transformer for crystal set help

    On the other hand the center tapped xfmr might have been what he had in his junk box. Cheers, Chris
  3. CDRIVE

    Audio Through Relays

    Well that's two misconceptions that need to be dismissed. The first one,... that all audio signals are AC is untrue and the second, that both conductors need to be switched is also untrue. Regarding the first misconception; yes it is true but only the signal that is driving the speakers. The...
  4. CDRIVE

    Audio Through Relays

    GPG, you appear to be a man of few words but you post stellar links! This is an excellent link that I will file along with all my other important links. Then I spend most of my time trying to remember where I put it. Cheers, Chris
  5. CDRIVE

    Audio transformer for crystal set help

    Actually this next quote is far more likely... This is a bit off topic but do you live in a Library?:D Cheers, Chris
  6. CDRIVE

    Possible help programming a Picaxe 08?

    BobK posted this link in a different topic than yours but I think you'll find it informative also. https://www.electronicspoint.com/resources/using-a-bipolar-transistor-to-turn-a-load-on-and-off.30/ Chris
  7. CDRIVE

    Audio transformer for crystal set help

    Oh a Dummy Fail Safe! :D One old fart to another.. Salute! Chris
  8. CDRIVE

    Possible help programming a Picaxe 08?

    Sorry to say I'm a long way from being healed but it hasn't kept me off the bike. Showering is a pure joy each night! :eek: Thank for asking Martin. Chris
  9. CDRIVE

    Audio transformer for crystal set help

    Yes, as Bob said... The CT isn't used in that circuit. What's the diode for in the supply rail? Cheers, Chris
  10. CDRIVE

    Possible help programming a Picaxe 08?

    I ran your code and was shocked that it didn't throw multiple errors. I can tell you this though. Placing multiple commands on a single line is not good programming SOP. It will make debugging longer programs harder to read and harder to fix. It will also inhibit the simulator's ability to pause...
  11. CDRIVE

    Audio transformer for crystal set help

    I looked through this thread but I didn't see the schematic of your circuit but since it specifies a center tapped xfmr it's probably configured as a Class B Push - Pull output. What Duke says here (he's an old fart) is quite true. At that time it was not an easy task for engineers or techs to...
  12. CDRIVE

    Possible help programming a Picaxe 08?

    Read Manual 3 (Interfacing Circuits), page 29 for proper LDR interfacing. A sample ReadAdc code snippet is on the same page. The ReadAdc code includes a variable or variables that are needed to store Byte data. You can read Manual 1 (Getting Started), page 53 to help understand variables...
  13. CDRIVE

    Possible help programming a Picaxe 08?

    I can't imagine how that code can't be puking up errors. I told you more than once that LDRs are NOT digital devices. They're ANALOG! Did you lookup the ReadAdc command? I will make a deal with you. If you agree to loose the LDR and replace it with a PhotoTransistor I will draw the circuit and...
  14. CDRIVE

    Audio transformer for crystal set help

    Errol, I buy lots of stuff from China on ebay. I guess about 1 out of every 20 orders don't make it here but the seller or ebay always credits my paypal account. You can't be in a hurry though. Typical 20-30 day delivery time. Good luck, Chris
  15. CDRIVE

    supply electrode with the humidity of the soil

    This might be considered old school since it would include a relay but the 555 can be used to cycle a DPDT relay wired the same way they're used to reverse polarity for DC motor direction control. Come to think of it a DPDT relay wired in this configuration constitutes the electromechanical...
  16. CDRIVE

    Audio transformer for crystal set help

    Good luck with your project but from a purist perspective "Crystal Sets" can't have active components. At this point in its life your project is now a Transistor Radio. Chris
  17. CDRIVE

    Possible help programming a Picaxe 08?

    LDRs are not a good choice for digital inputs. They're generally used with a Picaxe by using an ADC ("A"nalog to "D"igital "C"onverter) pin. Hover your mouse over each pin (Tool Tips) of the 08M2 image and you will see which pins accept ADC input. Typical code and circuitry is found in both...
  18. CDRIVE

    Possible help programming a Picaxe 08?

    No not quite. In that code the "If" statement tests if C.1 is high (= logic 1) or low (= logic 0). The "Then" statement specifies what to do if it is high (= logic 1). The "Else" statement is an instruction of what to do if C.1 is low (= logic 0). EDIT: I should mention that in the world of...
  19. CDRIVE

    Help with using shift register to expand uC output

  20. CDRIVE

    Possible help programming a Picaxe 08?

    OK, we'll start with some basic code. When you run this in the 'Simulator' click C.1 (Animated Chip Image) with your mouse. This will bring C.2 High. Click C.1 again and C.2 will go Low. The state of the pins will be simulated by changing pin color. A clicked pin will change from light Grey...
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