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  1. Old Steve

    Need Help in mosfet switching strobed LEDs

    Well spotted. I didn't notice that. :oops:
  2. Old Steve

    Need Help in mosfet switching strobed LEDs

    *steve*, the reason I said it's fine to use a P-chan for high-side switching is because these days some P-chans have a surprisingly low Rds-on. 0.2 ohms isn't uncommon, unlike in years gone by. I use them often, when high-side switching is essential. This is what I've been using lately:-...
  3. Old Steve

    Need Help in mosfet switching strobed LEDs

    Yep, use P channel for the upper MOSFETs, then pull the gate of the P channel low to activate. (Exactly opposite to the lower N channel's operation.) Best to use a tie-up resistor on the gate of the P-channel MOSFET, then an NPN transistor in common-emitter mode to activate it with a positive...
  4. Old Steve

    Beginner project

    Yep. And by using an Arduino, there's no shortage of people that can help with coding. I'm new to Arduino myself, (mine hasn't even arrived yet), but I'm very familiar with C/C++, so writing the code wouldn't be too difficult. (And more efficient in C.) All my practice so far has only been...
  5. Old Steve

    Mind & Infra Red Controlled Robot Car

    Eureka - I got the brainwave graph working, on serial input from a PIC via RF. It's working great. It takes serial input at 19200 baud. (Simulated values, of course - no headset yet.) When I get it completed, and you get to that stage, I can give you a copy if you like. I can compile it to an...
  6. Old Steve

    Beginner project

    Weaver, there's no 'one component' to do the job, but basically two could do it, as we've been discussing - a micro-controller and a H-bridge driver. The H-bridge simply reverses the connections to both sides of the motor, while the micro controls the timings and provides the direction control...
  7. Old Steve

    Mind & Infra Red Controlled Robot Car

    I'm very pleased to hear that you're not simply copying the code from the book. It might get the job done that way, but not 'exactly' how you'd like it, plus you wouldn't learn much. And if you're competent at Physics, you're not as bad at Maths as you think. :D Physics and the associated...
  8. Old Steve

    Beginner project

    If it was called for, then it could be added. Again, that's up to Weaver and the fisherman, not us. They provide the spec, we design it. (All for free, too, here.)
  9. Old Steve

    Beginner project

    That's why I mentioned a pot for 'wind-out' delay in post #13. The in-outs, (jiggles?), were only listed as 2 seconds each way, but the second pot I mentioned in the same post could also adjust them. I only mentioned 'multiple-timings', pushbutton operated, in post 15 for fancier patterns...
  10. Old Steve

    Beginner project

    But that's not what was asked for. Multiple timings would be easy, if it was asked for. (Pushbutton to select the pattern.) And one 555? I'd like to see that. :rolleyes:
  11. Old Steve

    Beginner project

    A couple of pots maybe - one for the in-out delays, and one for the 'wind-out' delay. And a manual 'rewind' button, to pull the line in to it's start position, both as a reset in the event of an interruption to the power during operation, and when fish are caught or fishing is finished. On the...
  12. Old Steve

    Beginner project

    I've been thinking about future upgrades - if Weaver was to buy two Arduinos, one to stay in the box, and a second one for uploading the program, a new program could be emailed to him (or the fisherman) for uploading. Saves either taking the first one back out of the box, or providing an...
  13. Old Steve

    Beginner project

    Yeah, that was my first thought too - an oscillator running at 4sec per cycle, but it's got to feed out the line first, before starting the 2 second in / 2 second out cycles, then be able to wind the full line back in again. It would need more than just an astable w/ counter unfortunately. By...
  14. Old Steve

    Beginner project

    Actually, instead of a stand-alone micro-controller and compiler/assembler/programmer set, an Arduino is a cheap option. Mine was only AUD$8.00 with cable, delivered. The IDE is a free download too.
  15. Old Steve

    Mind & Infra Red Controlled Robot Car

    Curiosity finally got the better of me, so I bought a copy of the book. Now I see how you plan to do it. Using the code from the book. :D
  16. Old Steve

    Beginner project

    Yeah you're right. An oversight. @Weaver, buy a box for it too. :D I'm still looking for the beginner aspect too. Mind you, if Weaver knows anyone with enough electronics know-how to solder it all onto a "vero" board or similar and put it into a waterproof box, one of us here could easily draw...
  17. Old Steve

    Beginner project

    My answer would be to use a micro-controller, controlling a H-bridge motor driver circuit. You'll need a micro-controller, (with compiler/assembler software), a programmer and associated software to program the chip, a H-bridge capable of handling your motor current to provide the fwd/reverse...
  18. Old Steve

    Number of batteries

    *steve*'s answer is more correct from a practical point-of-view. There's no way that you can connect them, keep the 2.5Ah capacity per cell, and totally drain them in one hour. You can only skim some off the top, if you get what I mean. Just buy a car battery as Dave suggested, and even then...
  19. Old Steve

    Number of batteries

    2.5Ah at C/5 = 500mA drain to have an effective 2.5Ah capacity (per cell). C=2.5Ah 2.5/5 = 0.5A for 5 hours 50 times that drain, (25A), = 6 minutes or 12 minutes for 2 in parallel as you want. BUT, the capacity is (waaaay) less than 2.5Ah if you draw that much more than 0.5A. Let's say they...
  20. Old Steve

    240vac capacitor type?

    ^ What he said - I get 160mA at 230VAC 50Hz. (Xc=1447 ohms) Edit: That works out at 37W load before you even connect anything. Even worse at higher frequencies.
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