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  1. Alec_t

    Wanted: 2sk1058 mosfet

    The 2SK1058 is obsolete. More modern MOSFETS with the same package style and better specs are available. Providing the pinout is the same they should be ok as drop-in replacements.
  2. Alec_t

    Need help understanding this circuit (Mixing board meter bridge)

    Can't you just swap the E2 and E3 connections? That seems an overly-complex circuit for just performing a toggle function with complementary outputs.
  3. Alec_t

    Question on reversing polarity for DC Motors

    Won't the switch also need a centre 'off' position?
  4. Alec_t

    Wanted: 2sk1058 mosfet

    How about one of these as an alternative?
  5. Alec_t

    Need help finding power source for solenoid

    That would be my guess, too. How you get that particular solenoid to push (other than relying on the spring return)? Looks to me like it's pull only, misleadingly described as push-pull.
  6. Alec_t

    Saft Power Systems PSU problems

    You might want to edit your thread title. This has nothing to do with shafts, but the 3342 pic does show the word Saft.
  7. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    You would have to do the energy budget sums. You're looking at, say, 6V x 1/4A = 1.5W per solenoid when energised. Multiply that by the average duty cycle of each solenoid and the average number energised simultaneously. Now compare with the energy output of your proposed wind/solar power source.
  8. Alec_t

    Which LED do I need?

    Sounds about right. In my previous car I had to replace a LED which had dimmed considerably. I calculated it had been in use for ~50,000 hours.
  9. Alec_t

    Oscilloscop trace at sceen bottom

    Welcome to EP! As Harald says, but it's also possible a fixed resistor associated with the position adjustment has come adrift.
  10. Alec_t

    Which LED do I need?

    If the 5k1 current-limiting resistor is external to the LED light itself then any 3mm diameter green LED will do. Most green LEDs have a forward voltage of about 2V, so in the circuit shown the current will be (16V-2V)/5k1 = ~2.7mA. That should be enough to give a reasonably bright indication...
  11. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    I doubt it. I don't think scaling the values for one solenoid would give you anywhere near accurate pull-in/drop-out values for a different solenoid, because of different geometries, spring constants etc. If you have some resistors in, say, the 3-30 Ohm range and able to handle 1/4A you could...
  12. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    Not sure what you mean. I was considering 1.5V and 6Ω and using Ohm's Law. 4.5V would require a series resistor of 12Ω to give 1/4A. But that 1/4A is the already-determined minimum pull-in current; the drop-out current (which you have yet to determine) will be less.
  13. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    I can't see 30AWG surviving the typical rough handling it would get on stage :).
  14. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    Since each solenoid will be drawing around 1/4 Amp (you might get away with less, using a >12Ω bypassed resistor), 6 or more on simultaneosly will put a big load on those poor little AA cells. Their life will be short and sweet. As for the Pease circuit, all components should be readily...
  15. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    In that case 3 AAs (4.5V nominal) should pull it in with 12Ω in series. Rather than 12Ω I'd try the Pease circuit with 10Ω as the bypassed resistor, to allow some margin.
  16. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    That's encouraging, providing it exerts enough force. Presumably the battery faded. Definitely should be present.
  17. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    Certainly worth doing that test. Try the solenoid first with 3 A cells in series (definitely should pull in, as per spec), then 2 cells, then 1 and report back.
  18. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    Before investing a lot of cash in all those solenoids I'd be inclined to test just one with the Pease circuit to see if it behaves as you'd like. If the solenoid 'bottoms out' when it pulls in at full current, there's a good chance it will stay like that with reduced current. If, however, it...
  19. Alec_t

    Solenoid Driver Circuit Without Using Arduino

    You would also need to know the minimum pull-in voltage and the drop-out voltage to calculate the optimum resistor value. Can you post a link to the solenoid datasheet? Do 'push' and 'pull' require opposite polarity energisations?
  20. Alec_t

    digital timer that can be set to a minimum of six different times

    Googling 'pill timer' or 'pill reminder' brings up lots of hits but, like AK, I think it will prove difficult to find something meeting all your requirements. Good luck with the hunt, though.
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