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  1. Arouse1973

    ESD protection for mosfets?

    Galvanic isolation will not protect a piece of equipmentt from an ESD event. It may help upto 8KV if your lucky. You need correct ESD preventative measures if you want to protect MOSFETS. Adam
  2. Arouse1973

    how to calculate battery parameter for this

    480KWh Is double what he needs isnt it? Adam
  3. Arouse1973

    battery usage

    What? You realy need to give more details in your posts. What capacity is your battery? It might run a clock for 100 years I dont know. Unless we know what type of battery it is.
  4. Arouse1973

    Help choosing a capacitor for a toy

    That's the whole point, to try and match the energy inside even a little battery takes an enormous amount of capacitance. Adam
  5. Arouse1973

    Help choosing a capacitor for a toy

    C=I*(dV/dt) = 0.001*(0.2V/0.33) = 6.6F Edit: This is wrong it should be C=I*(dt/dV)=0.01*(1200s/0.2V)= 60F So the voltage at the end is 1.3 which is a difference of 0.2. The current used is 10mA over a time period of 20 minutes which is 0.33 of an hour. I just used some figures to show you...
  6. Arouse1973

    Help choosing a capacitor for a toy

    Oh yeah sorry. I just used 10mA as an example. Adam
  7. Arouse1973

    Help choosing a capacitor for a toy

    Ok so a starting voltage of 1.5 Volts and a finish voltage of 1.3 Volts for 125 seconds is roughly 6F thats 6 Farads of capacitance. You should be able to get a 2.5 Volt version no probs. Adam
  8. Arouse1973

    Help choosing a capacitor for a toy

    Thats easy to workout if you know how much energy the toy uses. Does it have lights and sound? You might be looking at a super capacitor. I think you will be supprised in the size of capacitor needed to run something like that for two minutes and still hold the voltage. Are you able to measure...
  9. Arouse1973

    Common mode choke polarity

    How is it failing, what standard, directive are you working to? Is this just the standard conducted immunity testing? This is strange as a common mode choke is normally good at this sort of thing. Can you post circuit diagram and what choke you are using Adam
  10. Arouse1973

    Help with foot pedal modification

    If your happy to work with the range of 0 to 2.5 Volts then another 2K resistors connected from 5 Volts to one side of the pedal and connect the other side of the pedal to 0V, then where the resistor and foot pedal connection meet is your tap of point and will go from 0 to 2.5 volts. If you want...
  11. Arouse1973

    Is this possible??

    Does the laser have it's own regulator? It could be there is some capacitance inside which is holding the supply up momentarily. So using a relay might not work. If it's just powered from the D.C adaptor then a relay should work as this will isolate the laser from the capacitance inside the...
  12. Arouse1973

    portable speaker help

    Ok I am thinking something along these lines. The only concern I have is about the power adaptor, we could put another diode in line with it's power lead depending on the type you choose. But if the battery is flat and you plug in the power adaptor and you try to use the amplifier then it could...
  13. Arouse1973

    portable speaker help

    Looks reasonable. Couple of questions. 1) Do you have a solar charger in mind or are you planning on just connecting the battery to a solar panel? 2) What is array is this just a direct power connection to the battery. 3) What is load and why is it not connected to anything? 4) Will a 2.1 mm...
  14. Arouse1973

    Can this circuit works What changes I have to make to Drive 1w Leds on same circuit

    Ok cool.
  15. Arouse1973

    Can this circuit works What changes I have to make to Drive 1w Leds on same circuit

    Maybe this will help. You may have to register to see this link I am not sure. https://groups.yahoo.com/neo/groups/LTspice/files/%20Lib/ Cheers Adam
  16. Arouse1973

    Starter Solenoid Switch

    For that current and the fact it's a solenoid an MOV is your best bet yes. This will release the solenoid quicker than a diode will because of the higher clamping voltage. Time=Energy/Power Note: Observe the VGS max voltage if you do this. Adam
  17. Arouse1973

    LED timing with multiple variables??

    I think you will struggle to do this with a 555. Your best bet is going to be a micro processor. Adam
  18. Arouse1973

    Can this circuit works What changes I have to make to Drive 1w Leds on same circuit

    :rolleyes: Where did I put that blonde hair dye now? That's scan reading for you. Sorry Harald Adam
  19. Arouse1973

    Brushless motor and ESC

    A 125 Amp power supply rated for 12 Volts may give out a much higher voltage if not regulated. This could damage the ESC which probably has a max input voltage of 14.4 Volts. Do you have details of the PSU? Just a thought Adam
  20. Arouse1973

    Generate trapezoidal waveform for high power amplifier

    I am not sure Bob but I think this just might be his attempt at something? Adam
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