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  1. (*steve*)

    Hot Carrier diode

    A hot carrier diode is also called a schottky diode. The answers to your questions can be found on the wikipedia page.
  2. (*steve*)

    Motion detector circuit

    It's remotely possible. Placing a 1k resistor in series with it should eliminate the possibility without affecting the circuit substantially.
  3. (*steve*)

    Resistors, Capacitors, Zener diodes... Why the funny values?

    You might wonder why you can't always get the value of resistor you want. 6Ω sounds easy, right? What about capacitors. Why 470uF and not 500uF? Are these chosen at random? Why, why, why do they seem to want to make it hard for me? And why aren't there more resistor values between 1kΩ and...
  4. (*steve*)

    Resistors, Capacitors, Zener diodes... Why the funny values?

    (*steve*) submitted a new resource: Resistors, Capacitors, Zener diodes... Why the funny values? - An explanation of the E-series and why those funny values are used. Read more about this resource...
  5. (*steve*)

    Logic behind resistor values

    The numbers are not chosen arbitrarily at all. There is some (not a lot) of maths behind it. The numbers are chosen so that they follow a geometric progression with a certain number of values per decade. For E3 values (the earliest and now unused series, there were 3 values per decade. That...
  6. (*steve*)

    Ethernet transformers from Mouser -- awesome service

    If you go to mouser. Com.au you get prices inclusive of vat (10%). Ordering from mouser. Com you get to pay currency conversion fees on your credit card plus the potential for input duties and get if the order is large enough (under $AUD1000 is usually ok) I generally order from the US site...
  7. (*steve*)

    DROPPED FLUKE 323 AC CLAMPMETER REPAIR - DIY but need advice

    This is for AC measurement so it won't matter which way around the wires go.
  8. (*steve*)

    Two analog inputs to 1 output (+logic)

    The kill switch can control an analog multiplexer which either allows the analog "go" voltage through or selects 0V. A simple version might be a series resistor to limit the current from your "go" voltage and a MOSFET which shorts output when the kill signal is asserted.
  9. (*steve*)

    Need a simple circuit to reset a device very X minutes

    Simplest (for a certain definition of simple) would be a 6 pin microcontroller. It may be able to power the Bluetooth device from is output pin. If not, add a MOSFET and a resistor.
  10. (*steve*)

    Ethernet transformers from Mouser -- awesome service

    Yeah, I've done an order (over USD50 for free postage if I recall correctly) and it came pretty quickly, perhaps not as fast as yours though!
  11. (*steve*)

    Weapon worries...

    See https://www.fairchildsemi.com/application-notes/AN/AN-118.pdf page 3.
  12. (*steve*)

    Weapon worries...

    It is recommended not to use the 2 gate oscillator. Using 3 gates is guaranteed to oscillate.
  13. (*steve*)

    240VAC Transformer based 12 VDC PSU - Problem

    Yes. And it would be more stable. However an input and output capacitor are still recommended. LDO regulators can be quite stringent on their requirements, normal regulators far less so.
  14. (*steve*)

    Cleaning/lubricating products similar to Deoxit?

    It kinda depends on the switch, but mostly on his you apply it. If you're applying something that leaves a residue you should apply it only in the required area. Soraya which leave no residue night have as much of an issue with overspray.
  15. (*steve*)

    P channel mosfet

    R2 should go between the gate and source. Pulling the input (connected to R1) to ground will turn the light on. It would be preferable to increase R2 to 10k (make it significantly larger than R1)
  16. (*steve*)

    Over-voltage protection for op amp

    Because it allows you to use a lower value resistor (for lower noise). For logic, it will also improve speed by preventing the high series resistance from creating a significant RC delay.
  17. (*steve*)

    Audio Generator vs. Signal Generator...

    What do you call one that goes from 0.01Hz to 20MHz? :). I have another one that goes up to 990MHz, but I can't remember the lowest frequency off the top of my head. Other than frequency range, there are very few features that you couldn't find in both an audio signal generator or an rf signal...
  18. (*steve*)

    240VAC Transformer based 12 VDC PSU - Problem

    Ldo regulators can also oscillate. It might be worth sticking some 0.1uF caps between common and input, and also between common and output. Given that the regulator is not insulated from the heatsink, there may be something touching the heatsink or anything electrically connected to it that is...
  19. (*steve*)

    Cleaning/lubricating products similar to Deoxit?

    Isopropyl alcohol is great for anything that doesn't have a lubricant on it.
  20. (*steve*)

    Electric Toothbrush

    If it's sealed, even if you can fix it, you may have a hard time sealing it again. If the problem is water leaking into it, the damage may be hard to repair (if you shake it can you hear liquid inside?) If it's just a failed battery you might be able to replace it. It's also possible that the...
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