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  1. dorke

    thyristor vs triac

    What's in a name? Before the semi-conductor period, "name calling" started with Vacuum-Tubes or Valves. As in so many fields we have the Greecks to blame for;) They where named by the number of the Electrodes : DIODE : DI-ODE ,Di for dual or 2 ,ODE short of electrode TRIODE ...
  2. dorke

    Capacitor

    Yes 470nF . You can buy them on Ebay
  3. dorke

    Capacitor

    X2 is a class of "Across the Line Safety Capacitors"'used for reducing RFI/EMI. The normal operation voltage is 250V AC RMS , but they can withstand high voltage( up to 2500V impulses )and are actually tested to that. And they are "anti-flammable" as well. Here is a link
  4. dorke

    Capacitors

    Orion, You are using many terms in a very confusing way, sometimes wrongly: 1. "I know that a capacitor lets out the stored charge when it gets full" "gets full" is not an appropriate way to talk about capacitors The technical term is "fully charged". and no, the capacitor doesn't let that...
  5. dorke

    Please help a newbie connect woofer

    @Gryd3 ,you are describing the correct way to build a multi-way speaker box. However, I think the sub-woofer needs to be the only element in it's own box. And worst than that, the main problem is the lack of a dedicated sub output from the AMP. so this "sub-woofer project" is doomed from the...
  6. dorke

    Replacing A5sHB transistor (netbook)

    It is just measuring resistance from the battery and the Adapter connections to points in the circuit. if you get zero ohms reading than those points are shorted i.e connected. watch this ,it may help(4:40 on).
  7. dorke

    Capacitors

    Well, You are not very clear. A capacitor can only store charge (Q) , this charge creates an electric field in the capacitor. What do you mean by "regular"? There is a relation between the charge(Q),the capacitance(C),the voltage(v) and the current(i). di= C * dv/dt and Q=C*v in what...
  8. dorke

    Please help a newbie connect woofer

    The left photo is fine , the other one has a problem: It is not good to connect the tweeter with the mid in series. It is better to omit the mid in series with the tweeter. What are the LEDs you are using? and what is the transistor? You can have the left arm of the 1K resistor at the + of...
  9. dorke

    Modscan and Modbus Poll utility

    Youtube can be your friend, start here, and here
  10. dorke

    Good Soldering Station

    Sorry I don't ,as they say you get what you pay for... Despite the other opinion you heard here. Weller is a top brand with excellent products as I found out myself for many years of using it. Personally I do have the WECP-20 soldering station and it is a workhorse that didn't fail me for many...
  11. dorke

    Good Soldering Station

    I would recommend a Weller soldering station like the WECP-20 but for your budget you will be very lucky if you can get a used one...
  12. dorke

    Replacing A5sHB transistor (netbook)

    Yes
  13. dorke

    Please help a newbie connect woofer

    Welcome to EP. You are talking about a Sub-Woofer but the speaker you purchased is not really suitable for that purpose mainly because of it's 42Hz lower bandwidth-it should be lower. * The way you connected 2 woofers in parallel is creating an overload condition to your AMP it can't support 4...
  14. dorke

    Replacing A5sHB transistor (netbook)

    Please trace the voltage of the battery with an omh-meter(with the battery out) till it gets to the 3.79 voltage on the top Tr. Try to identify the trace of the DC adapter voltage on the board with an omh-meter as well. Please post two separate and clear(so that the device markings are...
  15. dorke

    Power Supplies - Common Terms and Limitations

    About the issue Constant Current : In my view it actually started with protection of the Power Supply against excessive output current which may damage the P.S . Most P.S actually only have that over current protection. In this case the output voltage is set to zero volts and the current is at...
  16. dorke

    Replacing A5sHB transistor (netbook)

    Your transistor is probably a P-channel Mosfet Si2305DS. From post #1 :"The battery charges well". This is strange, because you also say the battery voltage drops to 1v and fluctuates with the DC Adapter at post #3. With a charged battery only. check the voltages through those Transistors...
  17. dorke

    Help! Repairing water damaged PCB from Massage chair.

    "The voltages from the working side were much lower everything in the mv area" ? That is very strange ! Just to be clear: 1.The opto is MOC3020,correct? 2.The working side is the UP.the DW doesn't work ,correct? 3.The readings in post #278 are of the not working DW. 4.The reading of 1.09V (in...
  18. dorke

    Relay operations

    In this case you can use an all electronic solution which would be better in every way: smaller/cheaper/more reliable. If you want to go this way and need help, please post the circuit that drives the relay.
  19. dorke

    Power Supplies - Common Terms and Limitations

    I have seen linear regulated wall-warts and actually have a few. So, a slight correction in the "how do I pick a good supply?" section is needed.something like this: "If you need a constant voltage output use a voltage regulated wall-wart"
  20. dorke

    Help! Repairing water damaged PCB from Massage chair.

    Jonathan, you forgot to attach the pic.
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