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  1. Hero999

    Making PCB's

    I've always used toner for the silk screen. To make it more scratch resistant I cover it with a layer of conformal coating.
  2. Hero999

    Milliamp Question

    Why bump a three month old thread? I often find that there are plenty of people who talk a load of rubbish and think they know what they're talking about. You're right of course about unregulated supplies but I can't see how, someone who has asked such a simple question, understanding the...
  3. Hero999

    Polarity Switch

    Right now we're getting somewhere. I was going to say, I must have been under 8 years old when I built my first h-bridge. However I wouldn't have stood any chance of building a an h-bridge working up to 15MHz. What are you trying to do? How much current does the h-bridge have to supply...
  4. Hero999

    how can i charge a LiPo battery ?

    Lithium Polymer is just a variation on Lithium ion their chemistries and charging regimes are identical. To be picky, according to Wikipedia, your battery is not a lithium polymer but a lithium-ion polymer because a lithium polymer cells need only work when heated above 50
  5. Hero999

    Getting Started.. Suggestions

    You need to learn how to use Google, I found the following in a few seconds...
  6. Hero999

    Polarity Switch

    What are you trying to do? It's pretty easy to build an h-bridge with relays or a mechanical switch and virtually no electronics knowledge or soldering. If all you need to do is reverse a motor then it's the best solution. If you need to do something more complicated such as motor speed...
  7. Hero999

    500w blower

    Care to mention what the budget limit is? It's possible that buying a power meter is the cheapest solution.
  8. Hero999

    Noise Noise Noise

    Is the negative rail of the DC power supplies connected to earth? I take it the neutral is earthed? Please provide more information: how do the control boards connect to the motor? Is there any isolation between the AC and DC supplies?
  9. Hero999

    how can i charge a LiPo battery ?

    As a general rule of thumb, Li-ion batteries should be charged at no more than 0.5C. In this case, the instructions clearly state that it can be safely charged at 1C which is 800mA in this case to you can use the 600mA charger after all. This is no surprise; some of the smaller and more modern...
  10. Hero999

    500w blower

    You need a power meter. You can buy meters that give you the current drawn, the actual power, the VA and the power factor. Assuming the motor is inductive, these figures can be used to calculate the inductance and resistance of the motor whilst it is running.
  11. Hero999

    Wireless / Audio Video (TV as the receiver)

    Repeatedly bumping a thread is not going to increase the chances of you getting help: be patient, it often takes a couple of days before someone that knows the answer to drop by. The chances are no one has responded because you didn't provide enough information so if you must bump a thread then...
  12. Hero999

    Help Please

    Generally no. Look at the datasheet and note the luminous intensity figures. The viewing angle is also important, some LEDs are very bright but have a very narrow beam width and appear unlit unless you're looking directly at them. That depends on how powerful the battery is. That depends on...
  13. Hero999

    Help Please

    Small lithium batteries don't need a series resistor to power an LED because they already have a high internal resistance which limits the current. For a circuit that will power white, blue or violet LEDs from a 1.5V cell Google for Joule thief, although you might need to modify it slightly to...
  14. Hero999

    detectors in soccer

    I don't know, I've not had much real life experience with anti-shoplifting devices. I know how they work but wouldn't be able to tell you whether they're fast enough. Why don't you do some research and ask a manufacturer of an anti-shoplifting system?
  15. Hero999

    audio amplifiers

    Assume four step gain control refers to the gain select pins which can select gains of 20, 26, 32 or 36dB. A volume control can be added to this circuit using a potentiometer as with any other audio amplifier.
  16. Hero999

    stripboards?

    Ever tried DigiKey? I don't live in the US so I don't really know but many people on the Internet speak highly of DigiKey.
  17. Hero999

    50V, 50A H-Bridge IC needed

    If you use logic level MOSFETs for the low side then you won't need to perform any level shifting because they will be able to conduct the full current with 5V at the gate.
  18. Hero999

    Controlling LED Piranha with PWM controllers

    It looks like you can just leave the negative outputs unconnected.
  19. Hero999

    Noise Noise Noise

    Care to post a schematic? It sounds like you're having difficulties interfacing the AC circuit with the DC control side. How are you ensuring there's adequate isolation between the AC and DC circuits?
  20. Hero999

    50V, 50A H-Bridge IC needed

    No, you clearly don't understand how the circuit works. What voltage is driving the low site MOSFETs? I assume it's 5V so why do you need 10V zeners to protect it? Why do the zeners need to be bidirectional when the gate voltage can only be one polarity? The high side MOSFETs are connected...
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