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  1. kellys_eye

    Switching PSU drops 5v.

    The (lower) section of board where the PSU plugs into seems to be isolated from any outside interference by the opto-couplers so it's very unlikely there is anything off-board causing a problem - which leaves...... whatever might be under that big heatsink....... The top half of the board...
  2. kellys_eye

    Have seen many Youtube videos related to induction heaters but never for water?

    ....it can't be exceeded no matter what method you use - in the case of the OP's question, induction heating would be one of the worst and least efficient! What you've done is extrapolate the OP's original question to include PRE-heating of the water to reduce the amount of energy required to...
  3. kellys_eye

    Need help with a homemade speaker system please

    You won't get 'surround sound' without the appropriate driver card. The best you can manage with standard audio output is 'stereo' - and even then, you'll need some form of amplification to drive the speakers as the PC output won't have the power capability to drive them. A 5.1 surround sound...
  4. kellys_eye

    How do I wire a BMP085 Barometric Pressure Sensor?

    Devices that use I2C and the Arduino usually have 'sketches' to accompany them - these are short programs that you can embed into your own application and modify to get the data you want.
  5. kellys_eye

    Building an LED lamp with varying color and brightness

    Yes. The devices that drive the LEDs have a PWM output that can be used to drive another device (MOSFET) to increase the current handling capability and thus drive more powerful LEDs than they were originally intended. But those types of controller normally have relatively fixed colour...
  6. kellys_eye

    Omnidirectional Ultrasonic transmitter

    There's a (good) reason why the beam width is 'narrow' - is your requirement for a small (physically) sized transducer or a large beam width? The usual ultrasonic transducers used in hobbyist applications are similar to these: https://www.sparkfun.com/products/13959 and around 15mm in...
  7. kellys_eye

    Switching PSU drops 5v.

    Ah.... confusion, but understood now. the fault is on the board the PSU plugs in to.. Show us pics of that PCB and any schematic you have for it.
  8. kellys_eye

    Reverse current protection in car

    If you are driving an inductive load it is common to include a protection diode to prevent induced (back) e.m.f from causing problems - these can be high enough to destroy any switching transistor. It really depends on how your fob receiver controls the load - does it have a set of volts-free...
  9. kellys_eye

    Some info I read re UV exposure resist undercutting, with questions..

    Copper coating is identified by the weight - 1oz, 2oz (1 ounce, 2 ounce etc) and IIRC this refers to the weight per square foot. Obviously a 2oz copper is twice as thick as 1oz copper. You might specify 2oz copper for boards designed for higher current handling but, generally, 1oz copper...
  10. kellys_eye

    Have seen many Youtube videos related to induction heaters but never for water?

    Yes, if you buy already-boiling water (in bottles) you can get 100% efficiency.......... :rolleyes: but your example fails to take into account the energy used to create, build and install the heat pump - so, no, you can't......
  11. kellys_eye

    Repair WN3100RP WiFi Range Extender

    Damage like that looks to be a precursor to more substantial problems as yet undiscovered. Seriously, the board is as good as junk. I'd put the chances of fixing it at under 1%.
  12. kellys_eye

    Some info I read re UV exposure resist undercutting, with questions..

    You also get undercutting if you take too long to etch the board so fresh solution is very important if you want to etch finer lines. For transparencies it is always preferable to have the exposure (print) side against the resist. Most pre-sensitised boards I use come with peel-off black...
  13. kellys_eye

    Have seen many Youtube videos related to induction heaters but never for water?

    Of COURSE it's been tried.........:rolleyes: but you don't even have to 'try' to know. When it comes to generating heat (for whatever purpose) you can only get out what you put in MINUS ANY LOSSES. Any form of electronic process is, by design, a LOSS CREATING process. You can't get 100%...
  14. kellys_eye

    Repair WN3100RP WiFi Range Extender

    If the markings have burned off we cannot do that without access to the schematic which is not usually made available to anyone. Cheaper and easier to purchase another device.
  15. kellys_eye

    Having trouble building circuit?

    The LEDs are 'shorted' - think about how the holes in the breadboard are interconnected!!!!!! They are all connected to each other in a 'strip' and you've put the two LED wires in the same 'strip' of holes, effectively shorting them together.
  16. kellys_eye

    I've had an idea for an analogue synth sequencer, but I'm not sure what to Google

    A variable ASTABLE oscillator will change the frequency at which a pulse is created. But a device that has varying SPACE between pulses can also be a Pulse Width Modulation oscillator (PWM). This keeps the frequency the same but varies the time between the pulses
  17. kellys_eye

    Noisy Otari MX5050 BII-2 Tape deck

    :rolleyes: basic principle of fault location...... theses FETs switch in the relevant gain resistance to control the amplifier. If the wrong FET is being switched or the gain resistor has gone 'high' (and multi-megohm resistors are prone to) then the gain could be waaaaay too high and...
  18. kellys_eye

    Have seen many Youtube videos related to induction heaters but never for water?

    Probably because the KISS principle applies. Who wants a 'complicated' water heater?
  19. kellys_eye

    Building an LED lamp with varying color and brightness

    You could drive three high power LEDs (red, green and blue) using the cheap (and smaller) controllers simply by adding an external higher-power capability driver device (MOSFET usually). The proportion of R, G abd B you set will determine both the colour and intensity of the resultant light...
  20. kellys_eye

    Interface microprocessor with microcontroller

    ALL microprocessors/controllers have data ports and/or busses (in varying configurations) that allow input/output directly therefore communication between the two is only 'restricted' by the programmers ability to utilise the functionality of the relevant device - there is nothing 'physically'...
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