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  1. kellys_eye

    Musical Instrument Amps damaged by power surge or drop

    Component failure isn't 'guessable' and depends on the fault conditions at the time. If the main supply fuse is ok then check the main supply DC rail supplies. If you can find the main power supply section (photos would help) I could point to the places to measure at.
  2. kellys_eye

    Help with bridge rectifier

    The 5V supply can be taken from the 6VAC winding to deliver approximately 9V DC (bridge, smoothing and the 7805 regulator on a small heatsink). Get the +/-12v from the 21V lines as I previously mentioned.
  3. kellys_eye

    Anyone fancy designing a schematic?

    Look up the LORA range of transmitters/receivers. These are one-board solutions for such signal paths and have great range and signal integrity. Sorry, I'm not 'into' making individual constructions for clients though (at the moment).
  4. kellys_eye

    VCLFO debugging

    I can see some potential short circuits around the IC pins (U2) caused by inefficient cleaning/poor soldering.
  5. kellys_eye

    VCLFO debugging

    Pin 4 of the TL082 is showing as -0.5V They should be -12V. Is the -12V line ok?
  6. kellys_eye

    Multi meter question?

    I've only ever witnessed a multi-meter fuse 'event' - never caused or been the victim of one! The shipyard chief electrician was chasing down a fault in a distribution unit on the wheelhouse of a new vessel we were commissioning - in front of the vessels prospective owner and all the shipyard...
  7. kellys_eye

    VCLFO debugging

    Voltage source is plus AND negative 12V None of your readings show -ve volts. Are you using 0V as the reference? Have you got a proper split-rail 12V supply?
  8. kellys_eye

    Treadmill Motor Controller Board issue

    L1 and C7 look stressed to me... indicative of problems other than that caused by the original device blowing up! TBH the fault finding/repair process is beyond your limited capabilities so unless you;re prepared to send the board off to someone willing to have a closer look then the safest...
  9. kellys_eye

    PNV 57A Transformer

    Without doing an exhaustive internet search (an exercise left to the student....:D) all I can advise is the process involved such that you have a better understanding (or not) of what's involved. Often, for dedicated circuitry, the only choice is to make your own. High voltage modules...
  10. kellys_eye

    Help with bridge rectifier

    If the OP wants to make another hi-fi then the supply rails should remain 'balanced' for power consumption if the output stages are 'classic' (class B) as is required by +/- supply rails. If they are unbalanced then the circuit is clearly incorrectly biased and/or faulty!
  11. kellys_eye

    Stepper motor control as input? Arduino

    Can you access the sensor on the gearbox that supplies the pickup signal in the first place? The ECM will output a signal to the original speedo itself - have you got details of the signal FROM the ECU? Those 6-wire steppers usually have an associated driver chip (can't recall the device unit...
  12. kellys_eye

    Need help... Dielectric Grease used in contacts

    Dow Corning are the leading suppliers of such greases and have great data sheets for their products which themselves reference industry standards such as SAE AS 8660 as stated in this data sheet for their electrical insulating compound. Search their website for the grease and get the SAE spec...
  13. kellys_eye

    LCD Display (Basic)

    Is this just to display text and not act as an input/output device for other functions? The simplest way - and it's still 'complicated' - is to use a PIC or Arduino in association with an I2C-interfaced LCD (that you can get in all sorts of character numbers, dot-matrix etc). There are loads...
  14. kellys_eye

    Looking for a high current darlington transistor.

    The alldatasheet website has a parametric search option that allows you to specify the 'high current darlington' as a search word. Here's a link to what it found - 10+ pages of results! http://category.alldatasheet.com/index.jsp?sSearchword=HIGH%20CURRENT%20DARLINGTON
  15. kellys_eye

    Distorted waveform on Triplett 3432-A sig gen

    Got to ask the basic questions so sorry if this sounds 'simple' but what value part did you fit?
  16. kellys_eye

    Musical Instrument Amps damaged by power surge or drop

    I've got a schematic of the amp (very poor quality but .... meh...). First thing to check would be the positive and negative DC supply rails to the output stage. The PA stage schematic is as follows:
  17. kellys_eye

    Treadmill Motor Controller Board issue

    Can you get a close up picture of the board area around that device? Decently illuminated too? Download the data sheet for the device http://pdf1.alldatasheet.com/datasheet-pdf/view/118693/ETC1/STRG6653.html and you can see the basic interconnect for the component and the areas in which other...
  18. kellys_eye

    Inductor number L2001 melt-down

    If it's a common mode choke (which is looks to be) then it is only really essential to keep noise from being sent out on the data lines of the USB port. Unless you're running high speed devices on that port (video etc) you'll probably get away with just shorting both sides out. Crude, I know...
  19. kellys_eye

    rs485 communication

    Add code to poll the expected sources outwith the expected data stream. Unlikely the bus would be 'full' and the polling is only a minimal 'request' to expect a response. Could be done with dedicated device if you can't access an existing device to add code.
  20. kellys_eye

    Help with bridge rectifier

    What is the current requirement for the +/- 12V lines? If it is very small (and I suspect it's for a basic pre-amp circuit?) then you could simply fit 7812 and 7912 regulators across the +21 and -21V lines. Providing the current consumption is of the order milliamps you may not need heatsinks...
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