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  1. kellys_eye

    Line transient/load response circuit

    Apart from my GPIB comment, did you read the remainder of the post? It clearly states that you can use the LM317 to generate a supply voltage that can be 'stepped'... ....as you requested.
  2. kellys_eye

    M6013 capacitor tester

    As I understand those testers to work they rely on using the capacitor under test in a charge/discharge circuit based around the analog input of an ADC in the microcontroller - understandably you have to have a DISCHARGED capacitor as those inputs are invariably limited to 5V maximum. If you...
  3. kellys_eye

    39v 8a Laboratory Power supply circuit, Need Help

    Where to start? Probably by recommending you don't build it and try a more efficient way of doing it! What do you need such a supply for? Is your requirement specifically for high voltage/high current? Sure you actually 'need' this design? However....you should have some balancing resistors...
  4. kellys_eye

    Line transient/load response circuit

    For dedicated tests such as you describe it is usual practise to use a programmable power supply (GPIB enabled) but using a simple LM317 regulator and switching control resistors in/out of the program pin will achieve the effect. Get the data sheet for the LM317 and see the application for...
  5. kellys_eye

    LED strips for vanity/accent lighting?

    I have 'issues' over claimed luminosity values for LEDs over incandescents. Manufacturers seem to be able to take their own readings based on whatever spec they set - there is little compatibility for comparison over the whole industry. Inevitably they'll be used as indirect lighting anyway...
  6. kellys_eye

    Drive A 5w Led

    I'm guessing 'none'....
  7. kellys_eye

    Stepper motor control issue.

    Try grounding or taking the direction pin to logic 1. Don't leave it floating. With the motor disconnected apply a single pulse to the input (step) and measure the status of the motor drive output terminals. Do this repeatedly for subsequent pulses to determine the step outputs are being...
  8. kellys_eye

    Transceiver Circuit

    If the walkie-talkie is in 'receive' then ALL the switches will have the wiper (the arrow) connected to the points marked 'R'. Equally if the walkie-talkie button was pressed (transmit) then ALL the wipers (arrows) will be connected to the points marked 'T'. At no point are the wipers (arrows)...
  9. kellys_eye

    Line transient/load response circuit

    Check out the many projects on 'electronic loads' that abound the web these days. Feeding a squarewave to the MOSFET switching (load) device is all that's required. A 555 timer configured as a monostable (for one-shot transients) or astable (for repeating transients) driving a low Rds(on)...
  10. kellys_eye

    Network Time Display

    Think small - build a working version using standard sized parts first. Scaling it up is the 'easy' part.
  11. kellys_eye

    Static

    I create fantastic and expensive art every morning I get up and leave my bed unmade...... Such 'art' does nothing to help the publics impression of 'artists'.
  12. kellys_eye

    motor problem.

    Pfft - your power supply has no chance! 24V at 8A is the running voltage/current - it would probably take 20A+ to get that motor to start turning! This is known as switch-on surge. Unless your power supply can deliver a PEAK (instantaneous) current of 20A minimum you'll not get that motor to...
  13. kellys_eye

    Where to start

    It's usually easy to find the main controlling device part number on any of those modules and downloading the data sheet for them tells you everything you need to know. The Chinese don't actually invent the chips - they might fabricate them but the general spec for them is usually available...
  14. kellys_eye

    Static

    Not even art - one British TV presenter famously got some chimpanzees to paint 'abstract' pictures and a bunch of art critics (assuming the painters were 'up and coming') were asked their opinion - and as you'd suspect they gave all sorts of arty-farty, airy fairy comments, mostly heaping praise...
  15. kellys_eye

    motor problem.

    Such motors will show as good as a short circuit on a simple resistance check but this doesn't necessarily mean they are dud. 'Grubby' could well mean the commutator needs cleaning (the segmented copper bit). Have you checked the state of the brushes? How are you powering it?
  16. kellys_eye

    12 V motor loss of power

    As far as motor speed controls go the circuit you are using is pretty poor and the earlier recommendation to change to a PWM driver is highly recommended. Have you checked the gearbox grease?
  17. kellys_eye

    Help with my University Project !!

    Nice project, skillfully applied. 9/10 :D
  18. kellys_eye

    handy tracking device utilizing GSM with Real time image capture

    ....errr a GSM module and a camera module coupled to a controlling device (processor) perhaps? I'm expecting you to ask for a full schematic and programming details next....
  19. kellys_eye

    Transceiver Circuit

    That circled part of the schematic only changes the operation of Q1 from an 'accurate' crystal-controlled oscillator (during transmit) and a 'looser' oscillator used for the mixer circuit that Q1 operates as during receive.
  20. kellys_eye

    OP-amp help

    That diagram also shows the terminals labelled as 'S' and 'V' which I took to be 'signal' and 'volts' which corresponds to how a hall effect device may be utilised. If the OP measures 'V' to be a fixed DC voltage and 'S' to vary in frequency (many multimeters these days will read frequency...
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