Recent content by Bandgap

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    Standlight vs Voltage Doubler

    Hi Mr K You were up early! Or 'speed switch' as I remember. I may have copied your design Steve. Indeed, I still have shelves full - and what a lovely resource they are for tricky little circuit issues. For anyone reading this, flick through a Jim Williams application note to see a master at...
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    Standlight vs Voltage Doubler

    You are welcome. After I posted, I noticed Steve k had already explained it. Even though I was a hardware eng (and therefore cannot be trusted to write object-oriented code :), I have done two microcontroller-controlled dynamo light circuits. I went the software route because it cuts the...
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    Standlight vs Voltage Doubler

    Hi mbanzi I have a recollection that I designed that circuit - I may be wrong - I certainly used it in my old incandescent one-or-two-bulbs-in-series switch. the monostables are re-triggerable, and edge-triggered It is the period of the first monostable that sets the rotational speed at...
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    Standlight vs Voltage Doubler

    Hi Steve It occurs to me that it is worth following the peak power curve up to something like 6W, maybe 9W, then straying off the PP curve to keep voltages under control - in the same way that four of five leds in series (and a simple rectifier) would keep voltages to 12V or 15V. Efficiency...
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    Standlight vs Voltage Doubler

    Try FIGURE 4: Desktop CPU power supply in the same application note, BUT WITH A P-MOSFET IN THE TOP POSITION (meaning the top waveform would need inverting). Vdd can be up be anywhere between 4.5V and 18V if the mosfet gates can take it. And it does not need a separate 5V supply. The other...
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    Standlight vs Voltage Doubler

    Be aware - I think the MCP14628 cannot be used at 100% duty cycle - the upper mosfet will turn off after a pause and leave the load open circuit (as soon as you stop the switching waveform, the top mosfet gets starved of gate drive). An open circuit load will mean the input will climb until the...
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    Standlight vs Voltage Doubler

    This is not a problem mbanzi. Because of the low frequency involved, the resistor and zener combination is easy to design. Also, use a modification of figure 3 of your reference, only using two mosfets. Keep the two n-channel fets and replace the two p-channel fets with Schottky diodes. Then...
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    Standlight vs Voltage Doubler

    Hi mbanzi and SteveK Thanks for trying out the dead-time block mbanzi. On the subject f waveforms, I agree with what SteveK says. Just to add: one way to think of the driving waveforms for p and n-channel mosfets combined in that configuration is that for proper operation the waveforms are...
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    Standlight vs Voltage Doubler

    I am just as honoured to share a thread with you mbanzi, and the wise SteveK :) Am very much enjoying ATtiny85 data sheet - I am that sort of person. Would be trying to make a dynamo interface if I had a little spare time. How did youy get on with experiments? The other Steve
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    Standlight vs Voltage Doubler

    Thanks mbanzi, reading through it now. I wish I could find some time to build hardware as I am dying to try out a nice dynamo-fed synchronous buck converter. BTW, if I might be nosey, are you by chance the Arduino M Banzi? The other Steve
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    Standlight vs Voltage Doubler

    Interesting. Do you know anything about the deadband capability at, say, 200kHz output? - after a brief look in the data sheet, it seemed to me that deadband delays might only be available one count of the output resolution - so 1us if the resolution of the PWM was 1us. Thanks The other Steve
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    Standlight vs Voltage Doubler

    I almost don't know what I am saying here - but I believe 'C' is the equivalent of a good old flowchart. Software folk seem to read it like I read a circuit diagram (better than I read a circuit diagram!). And people can email code to each other - more tricky that emailing connections...
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    Standlight vs Voltage Doubler

    PS, the TC4451 (http://ww1.microchip.com/downloads/en/DeviceDoc/20001987C.pdf) is so powerful that it might make an output stage on its own - without external mosfets. it would be marginal, as 0.9ohm is quite a high output resistance (<0.1 from external mosfets is far better) But it does do...
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    Standlight vs Voltage Doubler

    You are too kind. I am pleased to be reading stuff from real software guys - I write code like monkeys type Shakespeare. There are far simpler ways to do that. I can sketch out some circuits for various parts, but I don't know how to post them - can you help. Also, i am not a power supply...
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    Standlight vs Voltage Doubler

    Nice idea Mr K, I never thought of a continuous solution, only step-wise solutions. so, a dynamo frequency>voltage converter, followed by a voltage>pwm converter, with curve-fitting in between if needed? Very nice However, I think an all-digital solution would need far fewer components and...
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