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  1. CDRIVE

    Best method to slow down a 12v motor

    Common DC brushed motors are predominantly resistive. You can approximate what they will draw using an Ohmmeter. So even if stalled it's resistive properties don't vanish. On the other hand I would expect a 6A motor to employ an integral cooling fan. If so and if experiencing a prolonged...
  2. CDRIVE

    Best method to slow down a 12v motor

    Hi LP. Curious, why do you say that? Chris
  3. CDRIVE

    Bike Computer PCB Repair

    Just a couple of notes here. There are two types of diode protection configurations. One is the series type that you mentioned but don't have. The other, the type you have, is the shunt configuration. The Cathode (-) is connected to the positive (+) trace and the Anode (+) is connected to...
  4. CDRIVE

    Schematic diagrams with antiparallel diodes

    Since I didn't see the entire schematic I thought it was a -700mV voltage source for something not shown in those two prints. Guess not. Chris
  5. CDRIVE

    Schematic diagrams with antiparallel diodes

    The Diodes in the RF input schematic (D305, D307) make sense to me but D918, D919 evoke questions. Why two of them (ying & yang) on that node? This is the common node of the bridge and is usually connected to GND for positive output voltage. As I see it this node can only swing negative anyway...
  6. CDRIVE

    trouble shooting - first try with electronics

    This topic should have been posted in the "Electronics Repair" section. That said I don't think messing with mains powered devices is a good choice for neophites. Get your feet wet with battery or low voltage devices first. Chris
  7. CDRIVE

    Best method to slow down a 12v motor

    I don't think that would disqualify a series connection but I'm open to discussion of why it would. Chris
  8. CDRIVE

    Best method to slow down a 12v motor

    Pulse Width Modulation (PWM) is the prefered method for 0 to max speed control. However, since you only need half speed and both motors are identical you could switch them from parallel wiring to series. When switched in series the current should half as well. Chris
  9. CDRIVE

    Using Arduino to read bipolar signal (from plants)

    Oh ok. I asked because drawing a schematic in a professional manner is an art form unto itself. Though it needed the mods that Harald gave you it was none the less drawn quite well. Chris
  10. CDRIVE

    Switching between two Inductors

    Your schematic has issues which I'm sure you didn't intend. Logically your inductor ends are not connected to the same point on the PCB but that's what your schematic indicates. You will be usinging a single pole double throw (SPDT) switch. The common of the switch should be connected to the...
  11. CDRIVE

    Using Arduino to read bipolar signal (from plants)

    Chiara, did you design and draw the original schematic that you attached in your first post? Chris
  12. CDRIVE

    Help with Jumbotron

    Back on line temporarily. Nice job Kris. ;) That should be easy for him to follow. Chris
  13. CDRIVE

    Help with Jumbotron

    thefstopjedi, I just saw your last post with the schematic. Sorry but no, that's not correct. Chris
  14. CDRIVE

    Help with Jumbotron

    I think that the series-parallel is where thefstopjedi is going off the tracks. I would have provided a schematic by now but I'm going through computer hell at this end and I don't currently have my Tina installed. I know that Kris will appreciate me volunteering him to do it for you...
  15. CDRIVE

    Tower Lamp Project (Advise to me)

    You could use a serial port or USB/Serial dongle too. Chris
  16. CDRIVE

    Help with Jumbotron

    That's not what I said!! Chris
  17. CDRIVE

    Help with Jumbotron

    If this is true you can string 2 chips (6 LEDs) in series and use a 24V source. The limiting resistor would be 240 Ohms per string. This would cut your current demand and resistor count by 50% Chris
  18. CDRIVE

    Help with Jumbotron

    Then your limiting resistor for each chip (3 LEDs in series) will be 120 Ohms. You will need 20 of them. Chris
  19. CDRIVE

    Help with Jumbotron

    Are you sure that you understood what Bob and I posted? Chris
  20. CDRIVE

    Help with Jumbotron

    Use the calculator as stated by Bob. Wire the LEDs from the Cathode of one LED to Anode of the next LED. The resistor will be 1 per Jumbotron and can be placed anywhere in the series string. Chris EDIT: Your supply voltage must be higher than 3.2V * 3 = (9.6V).
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