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  1. (*steve*)

    Etching first PCB problems - conducts between tracks

    Take out the board, rinse it in water, and look at it. Holding it up to the light can be very revealing...
  2. (*steve*)

    Etching first PCB problems - conducts between tracks

    Holding up to the light with the copper side toward you. Do you see any cloudiness where it should be etched?
  3. (*steve*)

    Etching first PCB problems - conducts between tracks

    Hey I missed that those readings were attributed to the poor etching. Yeah, I would expect a lot more continuity. Whenever I've done etching tests I've only ever seen open or continuity. I guess it's certainly possible to get any resistance, but the conductivity of copper is so high that any...
  4. (*steve*)

    Etching first PCB problems - conducts between tracks

    Sounds like you should have etched it longer. An old rule of thumb is to etch the board twice as long as it took to first appear as if it was etched. I find that for single sided boards you can get a good idea by holding the board up to the light. You can't do this as easily with double sided...
  5. (*steve*)

    HP 54510A Power Supply Smelling

    What voltage do you see on C30 and C31? Measure the resistance across all the filter caps (in circuit, power off and discharged). The resistance should keep on increasing until it gets reasonably high. Do any remain at a low value?
  6. (*steve*)

    HP 54510A Power Supply Smelling

    The clicking comes from a gross overload and the SMPS shutting down. When it restarts, it gets a gross overload and shuts down again. Each click is as a result of a cycle of this. If you can, disconnect the rectifiers and capacitors on the low voltage side one by one. When the clicking stops...
  7. (*steve*)

    NPN circuit isn't switching after power change

    My thought is that when the transistor was switched with an independent power source, it worked because whatever is being switched can have some undefined relationship with its own power rails. When you power it with the same rails as the device you may inadvertently connect a power rail...
  8. (*steve*)

    EEPROM read/write operation using stm8s003....

    http://bfy.tw/9nQq
  9. (*steve*)

    If I have a Li-Po battery connected to four quadricopter motors...

    "Just having it hover" is kinda the hard part. Sure, many can do it, but it involves feedback from various sensors that are each pretty complex. If you just set all the motors to run at the right speed to get it to hover in some environment didn't mean you can give in another. Change the...
  10. (*steve*)

    555 on/off circuit for 5v motor (w/ schematic)

    Another thing is that currents are measured in mA, not mAh. The latter is like speed being measured in metres.
  11. (*steve*)

    HP 54510A Power Supply Smelling

    It's not making clicking noises still is it? That is a reasonable indication of a short somewhere. My concern is that something is damaged due to that. The crowbar protection is there to protect the rest of the oscilloscope and it may damage the power supply when it activates.
  12. (*steve*)

    HP 54510A Power Supply Smelling

    Are you saying you see a significant voltage between 12 and 19? There is an inductor been those points. Does the voltage appear across it? You might want to fix one lead to 12 and then read voltages along the circuit until you get to 19. The may be a crack on the board, a dry joint, or some...
  13. (*steve*)

    HP 54510A Power Supply Smelling

    Yeah, low ESR caps will reduce ripple. However, excessive ripple might trigger the crowbar, but you've disconnected that... Did you try removing the SCR and checking it to be sure it's not shorted?
  14. (*steve*)

    Need some help with this motor control board

    There are several things that could be there, and be required to be there. Insulating washers and/or gaskets are common where the should not be any electrical connection. Thermal grease or those soft silicone gaskets improve thermal conductivity and for best performance you should use one of them.
  15. (*steve*)

    If I have a Li-Po battery connected to four quadricopter motors...

    First you need to locate some petalite. You can extract lithium from this to make your batteries. For making the semiconductors, you can start from sand. Frankly, it may be easier to purchase some of the modules you'll need. Unless you have a really good reason, and have significant...
  16. (*steve*)

    Current/heat dissipation control in an R-L circuit

    I recommend you increase the number of turns to about 1300.
  17. (*steve*)

    Car Battery/Car Alarm/Capacitor Question

    An alarm that discharges the battery that quickly does not sound right. However, a simple solution might be to connect a charger overnight. A bit of a pain in the bum though.
  18. (*steve*)

    Is there a circuit that can energize a coil on 110v, and to keep coil de energized on 220v.

    Bo Diddy sounds like a rapper :)
  19. (*steve*)

    Basic Soldering advice

    The method I use, and it comes after many years of experience, is as follows: Before soldering the joint, plunge the to a couple of times into a brass "sponge" to clean it up. Place the tip on the joint such that it has good contact with both the wire and the pad (or whatever the things are...
  20. (*steve*)

    Hello, Welcome! (Introduce yourself)

    Hi there nOObN60 and welcome to Electronics Point.
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