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  1. gorgon

    USB converter B type female to A type female

    Is there a reason you have connected GND to the shield of the Aconnector? Have you ohmed the pinout on the connectors? One of your solderings looks cold, it's very pearly. TOK ;)
  2. gorgon

    Problems substituting a relay

    Not a good idea, but you can put two zeners with half the voltage in series, and gain wattage. If you want 24V 2W, use 2 x 12V 1W in series. You could even use 3 zeners of 8V to expand this. The idea is to divide the load into equal parts to be able to sum the wattage. TOK ;)
  3. gorgon

    How to install a patch point?

    What is the impedance for the (patch) cable? Is it 600ohm line impedance or something else? Does the attenuator need to match impedance? TOK ;)
  4. gorgon

    idea help

    Sure. For you to get it here, depends on what it is. TOK ;)
  5. gorgon

    Newbie with LED question.

    If you connect 24V to a 3V LED you also need to add a resistor to drop the 21V not needed by the LED. To compute the value of the resistor you need to set the current through the LED. For 21mA you can use a 1k resistor, for 10mA use a 2k2 resistor. TOK ;)
  6. gorgon

    Knight Light

    @Harald Kapp Just curious; is 'xxUL' in the definitions the same as 'unsigned long'? TOK ;)
  7. gorgon

    12V Relay from a .2mA LED

    How do you get DC current from a 50Hz pulsed voltage? (I suppose it is 50Hz since the voltage is 240V, and no phase issue is mentioned) My best guess would be that you'll get a RMS current value, but that's an AC value. Since the voltage is halfwave rectified, the RMS voltage over the...
  8. gorgon

    Knight Light

    You can use any microcontroller with enough IO-pins to drive the LEDs. This function is a complete nobrainer for every type of microcontroller, you only need an io-pin for each LED you want lit. It may be necessary to use high efficiency LED or extra drivers, due to low drive capacity for the...
  9. gorgon

    Knight Light

    Would help if you posted the schematics, but from what you say I would think that most outputs are used already? two and two are connected with diodes, except one? The problem with 4017 is that it can not reverse direction, as you normally do with the Knight light? But first we need the...
  10. gorgon

    12V Relay from a .2mA LED

    You should have 1mA+ through that LED from the information given. The problem is that it is pulsed DC at 50Hz(or 60) and you should use the AC current range for your meter to measure the current. You should also be aware that you are working directly on the mains here, could get 'exciting'...
  11. gorgon

    how to reduce noise.

    What's the value of R4 and the other pulldown resistor? For TTL pulldown is generally a bad idea, and depends on the type of gate (U1,2 &3). If it is a Schmitt trigger NAND it could be ok. A TTL input need 1.6mA current to pull it low. TOK ;)
  12. gorgon

    how to reduce noise.

    Which logic family do you use for this? If it is TTL or LSTTL, the design could be iffy. If U4 is a LM555 you should review the design again. TOK ;)
  13. gorgon

    PCB reference designator question / iding a component

    Do you know where the PCB is coming from? Which country, nationality? Could it be a language problem? TOK ;)
  14. gorgon

    Power source

    Ok, you want a voltage controlled power that with an input of 0-10V give 0-60V out? Is this what you want? Or do you want a power that do a duty cycle(PWM) control from 0- 100% @60V, at an input of 0 - 10V? It all depends on what you want to drive, if it's LEDs you should think of the last...
  15. gorgon

    How to increase 555 timer output voltage

    The red LED is driven by 12V. The green LED is driven with only 8V(approx 2V drop in each 555). Given that red LEDs drop 1,7V and green LEDs drop 2V+, the current in the red LED is 22mA, and the green LED is around 27mA. To get the same current in both, the 220 ohm resistor should be 270 ohm...
  16. gorgon

    Old School Bell

    Could it be that the hammer is breaking the contact to one magnet and making to the other magnet for driving the other way? The capacitors could be noise reduction or timing elements. If driven by AC the frequency need to be very low, due to all the weight needed to move. TOK ;)
  17. gorgon

    optical punch card reader

    Looks great. You should cover the behind of the optotransistors. The ambient light will filter through the plastic from behind. Or you could paint them black on the lead side, to reduce the false light. TOK ;)
  18. gorgon

    optical punch card reader

    You could also add a separate optotransistor to measure the ambient light and use that to make an automatic threshold adjustment to your hardware, or measure the value and adjust your ADC readings accordingly. Good work. Multiplexing the channels will only reduce the maximum reading speed. If...
  19. gorgon

    Problems substituting a relay

    Yes, I see a problem with it. The 1uF capacitor equals a resistance of 3183 ohm, giving an available rms current of around 66mA, this equals to 1,4W to loose in the zener, with the ON LED current subtracted. If you use a 2uF2 capacitor the current will increase to 140mA and killing your zener...
  20. gorgon

    I want to make a battery pack that can make 7.5V at 3.0A.

    :D for some reason I used 1A as my reference, and you are of course correct. This was a real brainfart. :D With a 90% conversion efficiency the real number should be 3.33hours. TOK :o
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