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mixos

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Posts posted by mixos

  1. Hi faris :D , Welcome to Electronics Lab Community!!

    What exactly will be the power source? Something like this:

    Dynamo Powered?
    http://www.campingsurvival.com/dynflaswitba.html

    Shake Flashlight
    http://k3www.com/shake-flashlight.html

    Faraday's Principle (the same principle with the above)
    http://www.thinkgeek.com/gadgets/lights/5a9f/

    Also check this conversation here:
    http://www.electro-tech-online.com/viewtopic.php?t=5998&postdays=0&postorder=asc&start=0

    Tell us if you find or build something else.

  2. Yes right FireFly :D, that's what we are trying to do with this power supply right now, to make it reliably live up to its specs !!

    The transformer is good to be 4A or even 5A

    Staigen recommended a high value capacitor, something like 10000uF/50V if you can find one. Otherwise you can use some connected in parallel. The sure is that a higher value than 3300uF is needed.

    Rectifier bridge diodes 1N5402,3,4 are easilly overheated and for that reason a ready made bridge rectifier (at higher power rating, even 8A-10A) is proposed to be used off the board, attached to the box of the power supply for better cooling.

    We waiting Staigen to make his proposals, because he is a real PSU expert!! Where are you staigen :D ?

  3. Hello FireFly

    You can buy a plastic insulator that is made exactly for the dimentions of TO-3 package transistor and has good heat transfer characteristics. The clear plastic you have is old type. You can also find other kind of matterials that are like rubber . Almost all electronics parts stores has it.

    I attach you also an image that saws how to use it.



    Regarding the "Heat Transfer Compound" you can put it both sides of the mica isulator for better performance.

  4. Here is a simple 10 channel light bulb sequencer circuit which you can build up to decorate your house.

    OPERATION
    The circuit consists of 2 sections:
    1) Oscillator: The oscillator is built around IC555 wired in astable mode. The frequency of this oscillator is around 1 Hz (or slightly less than that) which can be increased further by decreasing the value of potentiometer VR1. The oscillator frequency determines the speed of effect. Higher the frequency, higher will be the effect speed.

    2) Sequencer circuit: The sequential lighting of bulbs is achieved using Jhonson Counter IC 4017 which has 10 decoded outputs. The output of 4017 increments by one on rising edge of each clock pulse from IC555. In the circuit the fifth output Q4 of 4017 is connected to its reset pin to reset the sequence after every four clock pulses. Here only four channels are shown but it can be extended upto 10 channels using all the outputs of 4017. In this case the reset need to be connected to Ground. For channels less than 10 the output one greater than required number of channels should be connected to reset pin to reset the cycle as soon as counter counts one greater than the required channels.

    The output of 4017 drives the base of NPN transistors (BC547) through 1k resistors. The LED in the collector loop of each transistor indicates the active channel. The emitter current of each transistor further drives the gate of Triacs (BT139) thereby turning them ON and supplying power to the lamp loads. Those who have 120V AC mains in their countries can also use this circuit without any changes. Many number of bulbs can be connected in parallel on each channel provided the maximum load on each channel does not exceed 3500W for 220V operation and 1760W for 110V operation.

    NOTE: DO NOT TOUCH ANY COMPONENT OF THE CIRCUIT WHEN IT IS ACTIVE AS IT MAY BE AT A VERY HIGH POTENTIAL AND MAY PROVE FATAL. I DO NOT GIVE GURANTEE OF ANY KIND. EXPERIMENT AT YOUR OWN RISK.

    Author: kinjalgp

  5. What you need is two "infrared LEDs" as mozikluv noticed... they look like a common led diode in clear plastic or violet color (see attachment) but they emmite light you can't see with eyes because it's infrared...

    Is this helping you? Did you finally understund it?

  6. just ordered 30 pcs of chips from TI..and I received it within 5 working days via UPS..and yet I request another 80 pcs.! of their products and they shipped them all promtly!! .
    In fact I just received a call from UPS telling me that my package has just arrived!!


    Kasamiko, can you tell as what chips you ordered?
  7. The following circuit is an example how to get power from RS-232 serial port. It gives regulated +5V power for logic circuits and also unregulated positive and negative power supplies for RS-232 transmitting circuit. The circuit gives only few milliampres power output because the power available from serial port is limited (and resistors R1, R2 and R3 limit current more).



    more info can be found here: http://www.hut.fi/Misc/Electronics/circuits/rspower.html

    or here: http://www.designnotes.com/CIRCUITS/compser1.htm

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