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jtamminen's Achievements


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  1. Thank You, I believe this will solve my problem!
  2. In static situation the power dissipation is very low, depending if the CMOS is "full-digital" or in some degree analog. With analog some current is needed to maintain the analog-voltages inside the chip. With digital this current is very minimal. When CMOS is switching state, the device consumes more current. This is because the FET-transistors inside the CMOS is changing state, thus requiring that the gate-capasitance to be carged/discharged. This is the main point where the energy is needed. Dissipation is a measure of the energy required to charge/discharge these capasitances through internal resisrance. The faster the transition speed, the more current is needed, but less time. The bigger the capasitance, the more energy is needed and more time. The smalle the internal resistance, the more current is needed. (but shorter time) With some older CMOS devices there was some design-"faults", which ment that in some transitions two transistors were conducting at the same time very very briefly and made a short-circuit for this brief moment. But in modern devices this is not happening. Hope this helps..?
  3. Hi. This is not a simple question. Actually we need more information: What kind of battery You are using? NiCad/NiMh etc... For example with NiCad the voltage is not so good indicator, as it stays in 1.2volts but still getting more and more charge. Finally the voltage goes down a little, indicating a fully charge. Other indicator is that when the battery is full, the battery temperature has gone up to about 40-degrees centigrate. Others here have answer with other battery-chemistry I believe.
  4. I have a sine-wave input, 45 to 60Hz, few hundred millivolts. The sine wave might have some distorsions now and then, and these distorsions needs to be replicated at output. (kind of mains-current monitoring device). The input varies from zero to some voltage, and is amplified to a 0-5volt level. That is the easy part.. now the problem: How could I "lag" the phase 90 degrees with analog design? The frequency is as said, 45 to 60Hz, but a constant in one application. It is possible to use different components with different frequency.. I know it is easy to do with a micro, A/D and D/A along with a ring-buffer, but I need to avoid digital logic here... Anyone able to give me a hint how this might be done? The output should be as close to input wave-shape as possible. Hope You understand my question, I'm not native english.
  5. There is *currently* no way to extract energy away from the coil ;( To my mind this is a glow-plug in a model-engine, that runs with methanol. The combustion cycle generates the heat that keeps the coil hot, and that ignites the next cycle again, getting heat from burning to be able to ignite again. The plug is not connected to power after startup. But to cool it down requires either cooling, or stopping the engine with other means. Mechanically that is very hard to do. Maybe a custom-made plug, with some kind of screening mechanism for the coil? Or removing the coil far enough from the combustion chamber into some pipe?
  6. Hi. I recently "discovered" the VNH3xxx series of full integrated H-bridge chip from ST. It might be a overkill for You, but it is a single-chip solution, that works fine with PWM. But it is available only in surface-mount... Anyway an interesting device and fullfills Your needs.
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