Search results

Search Forums New Posts
  1. C

    TURNS PER VOLT of a transformer winding

    Basically you wind the primary until you fill half the volume. The turns per volt depends on the VA of the core. You find the turns-per-volt from another identical core. You then multiply this by the supply voltage. Now you have the number of turns for the primary. Mic the primary wire and...
  2. C

    TURNS PER VOLT of a transformer winding

    At any place, either over the primary or secondary.
  3. C

    7404 Hex inverter stuck on 2.5v

    Take everything off the chip and put 1k between input and 5v rail. What is the output ? Put 1k between input and 0v rail. What is the output ?
  4. C

    TURNS PER VOLT of a transformer winding

    Simply wind 20 turns using any gauge wire and measure the voltage. This will take 10 minutes and require no electrical skill what-so-ever. This is what I have done for 40 years as I have no electrical skills at all.
  5. C

    ultrasonic receiver

    Buy a NEW Ultrasonic Sensor Module HC-SR04 Distance Measuring Sensor for arduino LO for $1.00 and you get $5.00 free shipping !!!!!!!
  6. C

    Low-Power Solar Charging IC

    2V 0.06W 300mA = 2V 0.6W 300mA
  7. C

    Low-Power Solar Charging IC

    and http://www.ebay.com/itm/Mini-6V-1W-Solar-Power-Panel-Solar-System-DIY-For-Cell-Phone-Chargers-Portable-/281997711521?hash=item41a85f98a1:g:wMAAAOSwJQdXCHlK
  8. C

    Low-Power Solar Charging IC

    You can get 6V 1.1W Solar Panel Poly Module DIY Small Cell Charger for as little as $1.50 on eBay and connect it directly to the phone and not have any messing around...
  9. C

    Delay off circuit

    You need a relay, a transistor and few other little bits. Stick them all together and it will work.
  10. C

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

    I have been in electronics for 50 years and I would not know where to start with a switch-mode design. Even a practical circuit would take weeks to design, build and test and modify. That's the IGNORANCE of most teachers. I sent letters to 2,300 IT teachers in Australia with a set of kits and...
  11. C

    Batteries in parallel

    Gryd3: You forgot to mention if the cells are they same type. One may be Leclanche and the other may be Lithium.
  12. C

    Convert +12V DC to -30V DC

    "the opamp is AD820, in the datasheet is wrote that it has a 5V to 30V single supply capability and ±2.5V to ±15V dual supply capability, does that mean that i can't supply it with ±30V??" duke37 "yes" How can you make a mistake like this after being in electronics for 40 years ?????????
  13. C

    programmable timed switch

    Just stick a microcontroller in the rectangle you have drawn and it will work.
  14. C

    Low-Power Solar Charging IC

    What is the voltage of your solar panel?
  15. C

    Help with optical sensors

    "Now, why do you want to use an emitter resistor? If you look at the application note, they generally don't use one." It doesn't matter if you use an emitter resistor or collector load. But working out the value needs 25 years of electronics experience.
  16. C

    Two power sources

    I want to turn an egg into a Maserati. How do I do it ???
  17. C

    fm transmitter using colpit oscilator

    Learn from here: Spy Circuits
  18. C

    fm transmitter using colpit oscilator

    The component values are all incorrect in your circuit for 90MHz.
  19. C

    Making a Powerful Solenoid

    Increase the voltage and see what happens.
  20. C

    convert 110v dc to 24v dc

    Where do you get 110v DC from ????
Top