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  1. Arouse1973

    Newbie circuit modification

    First thing is you don't have a resistor protecting the base from over current and the LEDs. See the first example of circuit. You may need a pull up from the base to the +V supply. This would explain the LED lighting with the chip removed. Always fit a pull up if you are planning on removing...
  2. Arouse1973

    Help with creating remote igniter

    Good Idea John. An RC glow plug, they are normally 1.5V and glow quite nicely. I would go for that I think. You can get them from your local model shop. They should also have the clips for them. Secure it to a small metal bracket connect he pin to + and the metal bracket to - of the battery and...
  3. Arouse1973

    Wiring Diagram For Energy Limiter

    Is this not just a high voltage resistor? I don't know much about fences but this would seem logical. Adam
  4. Arouse1973

    IR/UV Light

    Is this what you are after, and as Duke says you need a resistor for each LED. Adam
  5. Arouse1973

    Potentiometer Resistance ?

    You use a shunt regulator for solar panels to limit the current in bright sunlight. I think you will have problems having to keep adjusting the speed of the motor if you don't regulate it. You could then use an emitter follower current amplifier to control the voltage of the motor using the pot...
  6. Arouse1973

    Electronic Engineer

    You could try a temping agency.:)
  7. Arouse1973

    Help with creating remote igniter

    Now your using a coil? I think it would be better if you could supply a simple drawing with the dimensions you want the wire to cover and the type of battery you are using, Voltage and mAh. But initial thoughts is your going to need more power. Red hot is probably in the range of 800 degrees C...
  8. Arouse1973

    Help with creating remote igniter

    Increase the amount of wire slightly. It's that simple. More wire equals more resistance which equals less current. But you will get less heat. Adam
  9. Arouse1973

    perfect voltage source

    A perfect voltage source will have zero resistance and produce an infinite current as the load goes to zero. A battery and 3Ohm resistor is far from a perfect voltage source. Also a perfect current source will have an infinite resistance and produce an infinite voltage as the load goes to...
  10. Arouse1973

    Help with creating remote igniter

    For Nichrome wire the temperature rise is roughly as follows. For 32AWG the temp rise is approx. 32 degrees centigrade per watt. So for 12 inches of 32 AWG at 12V will be 12V/10.55R = 1.13A and power is I^2*R = 13.56W. Temp rise is thus 32*13.56 = 433 degrees centigrade. If you want to use a...
  11. Arouse1973

    Help with creating remote igniter

    The wire will have a resistance which will limit the current to the Voltage divided by the resistance. 12V/10R=1.2A. Your relay can switch 6A so this will be fine. The more wire you use the less current you will draw from the supply. I'll see if I can calculate the temperature rise. Adam
  12. Arouse1973

    Help with creating remote igniter

    32 gauge will have something like 10R/ft. So even with 1ft, the wire should draw approx. 1.2Amps. Adam
  13. Arouse1973

    Help with creating remote igniter

    Do you have a spec sheet for the remote unit. What power source are you using? What length of wire are you using? Adam
  14. Arouse1973

    Linear power supply design

    You have a very large capacitor on the output of the rectifier. A 4.7mF at startup could try and draw 20Amps or more from your circuit because it will have a very low ESR. I would reduce the value to say 1000uF and make sure you use an anti-surge type of fuse, I would move the fuse to before the...
  15. Arouse1973

    Multiple power sources

    If the batteries are primary cells, I.e non rechargables then yes you do need a diode. The diode has to have a reverse leakage of less than 1uA to conform to IPC standards. Look up ideal diodes, they are a better option. Adam
  16. Arouse1973

    Li ion (2.7v to 4.2v) to regulated 3.3v

    I think you need a SEPIC converter. Thanks Adam
  17. Arouse1973

    Heart rate sound circuit?

    Hi I have found a couple of things for you. But they will need you to do a bit more research to see if they are suitable. http://www.ebay.co.uk/bhp/recordable-sound-module http://www.soundjay.com/heartbeat-sound-effect.html Adam
  18. Arouse1973

    high frequency audio amplifiers

    Hi All decent audio amplifier ICs should extend beyond 20Khz.. That's about the top end of adult humans hearing limit. All you need is a passive crossover after the amplifier which blends the audio together at the correct frequency and power for each speaker. The power handling of tweeter...
  19. Arouse1973

    Heart rate sound circuit?

    It might have had a small sound chip in there to do this. Trying to reproduce the PQRST responce of the heart might prove difficult. I'll look into it and let you know. That's a good one I must admit. Adam
  20. Arouse1973

    power with line wire enter the wall switch and out going and there is no neutral

    Sorry didn't get a word of that. Can you send in a picture of what you want to do. Adam
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