Search results

Search Forums New Posts
  1. Arouse1973

    I am to design a switched mode psu without IC components.Help please

    They are expecting you to design a switch mode power supply without a controller IC and you don't have any experience in electronics. That's a bit unfair don't you think. Adam
  2. Arouse1973

    power supply

    He starts of ok then it goes to a lot of um I think possibly.... 1 or 2 Volts .... which is it, because that's double :) Base resistor, um... not sure about that one. Even at emitter currents of around 500 mA and a 500 Ohm base resistor the base current is going to be very close with or without...
  3. Arouse1973

    LTSpice Help

    You may find it works without the gmin options but I seemed to get a faster response by adding this. The other option can solve time-step too small issues by adding a very small delay to all the nodes. I have used this a few times before and it has helped. Adam
  4. Arouse1973

    PWM LED THROUGH MOSFET

    Ok one thing you could try is a Baker clamp, this prevents the BJT transistor from saturating fully and will be faster to turn off. This will only work if it's the BJT causing the issue, but it's worth a try. Adam
  5. Arouse1973

    LTSpice Help

    I don't know how good the model is. I got it to work by adding some series resistance to the power and signal sources. Also add the .options functions on the image I have posted. Adam
  6. Arouse1973

    LTSpice Help

    Ok let me look.
  7. Arouse1973

    PWM LED THROUGH MOSFET

    Hello and welcome to E.P. Can I see the circuit diagram please. Thanks Adam
  8. Arouse1973

    LTSpice Help

    Just tried it and it works for me. The OPAMP comes in as an OP37 not a MCP6L04? Adam
  9. Arouse1973

    RC filter-uncertain

    My initial thoughts are that the capacitor will bypass certain frequencies. Maybe the speaker the capacitor is across is a bass speaker or midrange? Adam
  10. Arouse1973

    fm transmitter using colpit oscilator

    Sorry Alec what do you mean, are you saying the circuit is not an FM circuit? Or was your reply not for me? Adam
  11. Arouse1973

    Detect harmonics with arduino

    More detail is needed... tell us about your project or is it secret? Adam
  12. Arouse1973

    fm transmitter using colpit oscilator

    Just put a simple audio amplifier at the front end and couple in with a capacitor. http://www.google.co.uk/search?q=colpitts+fm+oscillator&num=100&biw=1280&bih=800&prmd=ivn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjVlJLMo4LMAhUBkRQKHduqB2QQ_AUIBSgB#imgrc=N4f-P0BsXN3UCM%3A
  13. Arouse1973

    fm transmitter using colpit oscilator

    Yes correct Alec, you beat me to it. I dont think the OP knows what he wants. Adam
  14. Arouse1973

    fm transmitter using colpit oscilator

    Here is a circuit that will oscillate. You will have to adjust the component values for your own. I just added some values I thought might work.
  15. Arouse1973

    fm transmitter using colpit oscilator

    Is your current circuit not working? Where did you get the circuit from? Adam
  16. Arouse1973

    BLDC Power Inverter Problem.. Need Help Urgently

    What pin numbers are you using for the HI and LO pins on the MOSFET driver? Why are you outputting no PWM on most of the pins? Adam
  17. Arouse1973

    BLDC Power Inverter Problem.. Need Help Urgently

    Just a minor thing, I noticed some of the MOSFETs have missing connections. You have used the wrong symbol, you have a 4 pin model with body diode connection. Adam
  18. Arouse1973

    BLDC Power Inverter Problem.. Need Help Urgently

    Ok so you have a connection error or your lower FETs are on. The circuit should be fine so you must have an error in your connections. Can you post a picture of your circuit? Adam
  19. Arouse1973

    BLDC Power Inverter Problem.. Need Help Urgently

    What do you have connected to the gates of the lower FETs? Adam
  20. Arouse1973

    BLDC Power Inverter Problem.. Need Help Urgently

    Then you need to download a free package like LT Spice and draw the circuit in that. It is very bad practice to expect others to have to remember it's different. Others may even miss the part where you said it's different and that can cause confusion. Please download a free software package and...
Top