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  1. gorgon

    2:1 ratio step down transformer question from newbie

    If the transformer is like the ones in the picture, you hav (0 - 24V) - (0 - 24V) on four terminals. You connect the middle two, resulting in a 'three' terminal, 0(A) - (24V+0)(B) - 24V(C). The 50V output goes to the outer, A and C. The motor between A and B. (or B and C). The two are equal.
  2. gorgon

    Current Limiting Circuit

    If your regulators is limiting to 100mA they should do the job themselves. What type are they? If they are linear regulators 24 to 9 volt gives a big power loss and heat in the regulator, 1.5W at 100mA. If that is acceptable, no problem. TOK ;)
  3. gorgon

    10v Output to USB "Enter Button" Input

    Using an optocoupler with the transistor output connected in parallel with the 'Enter' key, and a resistor in series with the 10V input should do the trick. Just take care with the polarity of both signals. TOK ;)
  4. gorgon

    How to Size a Current Inrush Limiter

    To size the inrush limiter is easy. Set the max current you want at inrush, and use Ohm's law to compute the resistance needed at startup. Remember that the peak voltage is 155-160V for a 110Vac. The max current will be at peak voltage. The problem is to get rid of this limiter when running...
  5. gorgon

    Switching circuit making help?

    You should always use a resistor for pullups on TTL and TTLLS logic inputs. This is because the input is drawing current due to the construction of the chip, and you limit this current with a 1k resistor. Never connect TTL inputs direct to Vcc. TOK ;)
  6. gorgon

    RC TIMNG

    It all depends on the transistors base pulldown resistor, if it is too small related to the charge(timer) resistor you will get a resistor divider where the voltage is split between the resistors, never reaching the zener value(+LED ++) To get a really long time this way, could be to use a...
  7. gorgon

    Obtaining 250V, 500mA

    Shoting from the hip. If this has something to do with a 150V line driven speaker systems for audio sound, the normal way can be to use transformers to get the 150V. A good torodial transformer will also isolate the driver from the line. TOK ;)
  8. gorgon

    PIC16F84A Digital Clock (It works!)

    Blanking hour10: What you could do is to add 10 to the value in W in the H10 routine, and double(copy) the number of entries in the table from 10 - 19, making the '10' = B'00000000' This way you don't need to test anything. When the H10 value is 1, you get value 11 from the table. TOK ;)
  9. gorgon

    Obtaining 250V, 500mA

    A 150W power supply is never small in my experience, and with these criteria it's bound to be on the upper side of a normal size. Is there a particular reason that you need to drive the amp from 250V? why not go for a more doable value. 40V should be possible and with 3A you should have the...
  10. gorgon

    What is this part called?

    Swapping wires are a long way from PWM. If the response is fast you could try to make a bipolar PWM. The PWM periode will need to be a fraction of the mechanical turning time. If you send a symetric 50/50 bipolar PWM, you should i theory make the wheels stay in any fixed position, A 45/55 should...
  11. gorgon

    What does this mean by isolated?

    From the pictures of the PCB it looks like an optocoupler is used for the isolation purpose, but I could be wrong. TOK ;)
  12. gorgon

    What is this part called?

    The frist that came to my mind was to add a spring to bring it back to neutral position. Depending on how fast the turning action is, you could modulate the control pulsing with asymetrical PWM to get some sort of analogue control of the action. This will also be depending on how the electronics...
  13. gorgon

    What size cap do I need?

    You could try to keep the 22uF and add another bigger capacitor in parallel. What's the current drawn here, from the DAQ? Have you got anything over the motor, like a diode to short any reverse voltage spikes? Could also be that the DAQ itself trigger due to a inducted noise from the...
  14. gorgon

    Hello from another FOG

    Beats me, and I've had 5 more years to ponder :D TOK ;)
  15. gorgon

    What size cap do I need?

    If you add a diode and a capacitor before the regulator, you'll 'isolate' the regulator from collapses on the voltage supply. Put the diode in the V+ lead and the capacitor after it. If you already have a capacitor before the regulator, just add the diode. TOK ;)
  16. gorgon

    Hello from another FOG

    Thanks Dave, I've also done some PIC designs, since the company i worked in used them, and only the 16x series. They are not my favorite, and I prefer an instruction set more on the evolved side. These days there are loads of small controllers that are very good and easy to use. BTW how are...
  17. gorgon

    Hello from another FOG

    I registered here in the forum last year, and it's time to introduce myself. I saw the acronym FOG below in another introduction, and decoded it to be 'Friendly Old Geezer', among several 'interesting' variants. My name is Torfinn and I live in Norway. I'm 58 years old now, and I've been...
  18. gorgon

    help please

    I would think that the parallel 'variant' is with a switch, for high/ low switching. If it is parallel over the load, it should short it out, and break the fuse, if faulty. If in series , and faulty(shorted) the heat would be on high permanently, as described. If a diode I would use a 10 or...
  19. gorgon

    help please

    Without a schematics it is hard to know, but since the device is reducing the voltage to about the half on a meter, I would think it is a diode. Rectifying the AC gives about half the effective voltage, and effect. The only way to be certain is to take a look with an oscilloscope to see the...
  20. gorgon

    What does this mean by isolated?

    As long as your signal source is from a battery supplied system, you can use both. An isolated input is normally used where the signal source is far away or has a different power supply, and will inhibit ground loop noise to interfere with the signal. It is also preferable to use this when...
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