Search results

Search Forums New Posts
  1. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    One of the benefits of PWM motor control vs older variable (analog) voltage control is that it nearly eliminates loss of torque at low RPM. Chris
  2. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    No, Stu is not trying to detect room temp. He has a thermostat for that. He's detecting water temp and slowing down the circulation pump to insure the heater has sufficient time to heat the water. Chris
  3. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    Stu, a photo of your hookup will aid in determining if you made any wiring errors but as I've previously stated, it seems to be working as expected. ;) Chris
  4. CDRIVE

    Which PIC, LED PWM dimming

    Keep in mind that LED's are very fast devices. As compared to incandescent lamps they're lightning fast! Because of this the persistence of the human eye can't perceive what it appears to see as LED dimming until the LED (ON Time) falls below a certain value, which (I think) is less than 20%...
  5. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    Stu, the PWM output can't be accurately measured with a voltmeter. An Oscilloscope is required to actually see PWM voltage but you don't need one to know it's working. Your test lamp is telling you what you needed to know and seems to be working as expected. Yes, soldering the Thermistor wires...
  6. CDRIVE

    Measurement -2.5 +2.5 with ADC

    Now that has to be the EP understatement of all time. Many people adorn their walls with family photos. Here's a wall photo of one of Hop's grandchildren. :p Chris
  7. CDRIVE

    Building my own bench drill

    Miguel, is light machine oil hard to find in Cuba too? Looking at all of your photos you seem to have no shortage of rust though! Chris
  8. CDRIVE

    Building my own bench drill

    Miguel, thanks for posting the photos. It certainly clears things up. Chris
  9. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    Stu, here it is again with some notes. Chris
  10. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    In this image the wiper (center terminal) of the Pot is shorted to the bottom terminal of the Pot with a jumper wire. Is that what you're asking? Also, the Cap can be soldered to the Pot terminals or to the bottom side of the PCB directly between the GND and the 0 - 5V connector pads. It's...
  11. CDRIVE

    Power amplifier

    Hop, I don't see any correlation or comparable relationship between RF sniffers charging a Super Cap and then delivering a brief power burst as compared to continuous charging of a battery. Chris
  12. CDRIVE

    Which PIC, LED PWM dimming

    I should have examined your schematic more closely. I assumed that all the anodes were connected to Vdd. I now realize they're being sourced from the uC. If only one LED is on at any time then I don't see the need for driver transistors because you can bring the Cathodes low to Vss by inverting...
  13. CDRIVE

    Which PIC, LED PWM dimming

    From your schematic I don't see any reason you can't use the ULN2xxxx series transistor arrays but discrete BJT's are OK too. Either way each LED should have its own current limiting resistor. Chris
  14. CDRIVE

    Power amplifier

    Steve, I haven't started drinking yet today. That's probably why I don't understand your reply. I'll read it again in about two hours. :) Chris
  15. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    Stu, that cap will work fine but I'm accustomed to paying that much with free shipping. One other big difference is I'm addicted the Ebay's China vendors. The same item from China would cost about as much but it would be a pack of 50 or 100! :) BTW, these are very common caps and can be...
  16. CDRIVE

    Power amplifier

    I can garantee that if the logic of this concept were reversed, IE a battery powered transmitter wirelessly powering a recipient device, the waste involved would be instantly apparent. :eek: Chris
  17. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    The Pot is wired as a Variable Resistor (Rheostat). When connected in series with the Thermistor the circuit forms a Voltage Divider much like a Pot does when wired as a Pot. The difference here is that the Thermistor replaces or mimics varying (turning) the wiper pin of the Pot. The 100nF Cap...
  18. CDRIVE

    How to control the speed of a 24vdc pump from circulating water temperature?

    Stu, glad to read you have them. Yeah, those Chinese bargains are soooo difficult to resist! I can't add anything to what Alec suggested because it's exactly what I would have posted... verbatim. Chris
  19. CDRIVE

    Power amplifier

    At this time in human history I don't get this obsession with wireless power transfer. The entire concept is the antithesis of energy conservation. Chris
  20. CDRIVE

    Which PIC, LED PWM dimming

    That's opposite of what you posted, as the quote implies the Anodes are all common. Chris
Top