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  1. kellys_eye

    Noob teaching self electronics. Needs help!

    Meters to check ESR aren't particularly expensive. You can't test them 'in circuit' anyway (not properly anyway). Chinese suppliers are now delivering test sets that have LCD readout and will test practically ANY component - including capacitor ESR - with a digital display of that component...
  2. kellys_eye

    Oscilloscope? ?

    Nice as it is to own such test equipment (if you have the money, well why not?) it won't come into its own until you reach a point of understanding whereby the information it displays becomes of use to you. I'd be looking for a good quality set of tools and a decent multimeter first. You can...
  3. kellys_eye

    How could I convert/boost PWM frequency? 500Hz to 25kHz?

    That's what I call a 'make work'.....:D Not only would such fans be more expensive than conventional non-integrated devices, they are, as you have discovered, more complicated to control. A simple 2-wire fan will accomplish (I presume) what you want to do (cheaper) unless feedback of the...
  4. kellys_eye

    Please Help replacing 2 power adapters with 1 battery or power bank.

    Yes. There are power banks that are supplied for use with HDD readers - I have two. The come with the conventional molex connector to power the HDD but that can be easily removed. IIRC it was capable of delivering 2A at 12V and 3A at 5V but if you search around you might find one with a...
  5. kellys_eye

    Broken Mini USB pin on Capture Card

    The fact that the pins are 'staggered' on one and 'straight' on the other is not an issue - the pins are still numbered 1-5 left-to-right (or vice versa if it's upside down). If you fold the remaining pins (on the PCB) to a horizontal position you should be able to lay the new socket against...
  6. kellys_eye

    Alternative Materials for Homemade Circuitboards

    Another option is to use adhesive copper strip - obtainable in reels of various widths all over eBay. Drill whatever material you want to take the component leads (or do it 'hole-less' using SMD parts) and glue strips between the component lands - and the overlaps of course. Here's some I...
  7. kellys_eye

    Alternative Materials for Homemade Circuitboards

    You can purchase PCB material in a variety of thicknesses from sub millimetre (0.2mm) upwards. I have a number of sheets of both single and double-sided copper clad fibre glass material that I use to make 'landing pads' for HF circuitry by using a paper punch to make little 'dots' (that I then...
  8. kellys_eye

    How could I convert/boost PWM frequency? 500Hz to 25kHz?

    Where do you get the notion that the fans optimal PWM is 25kHz? You can control a standard DC fans speed at 50/60Hz (recall many domestic instances of such). A fan has a large moment of inertia and can be speed controlled at 50/60/100Hz with ease - something a software program could deal with...
  9. kellys_eye

    project request

    The key to any electronic design is to be found in the data sheets for the devices you wish to use. Many data sheets also include application notes that suggest how to connect, drive or program the device. If you have a basic understanding of electronics then working your way through any data...
  10. kellys_eye

    Multitasking with Arduino

    The Arduino has multiple 'ports' that can be used to drive many different accessories simultaneously. Check out any reputable Arduino seller and look for speaker and servo modules that can be purchased to connect to the Arduino. It's then a case of either writing your own software or...
  11. kellys_eye

    using power tool batteries !

    I'm not sure I recognise the need for the system as the OP wants it to be..... The lights/fan can't consume more than a couple of amp-hours (the amount that a simple tool battery can hold) and a couple of amp-hours drain on the main batteries is almost negligible as far as discharging them is...
  12. kellys_eye

    Static On My Radio

    I'm actually a Yorkshire man but married a Scot lassie - Nessie I reckon - but the interference can indeed travel along the wiring if it's a particularly poor example of electronic design i.e. many cheap Chinese knock-off lights are poorly designed and even more respectable makes fail to include...
  13. kellys_eye

    4th July

    Happy Independence Day to the American membership!
  14. kellys_eye

    Recapping a PSU -choosing the right replacement caps

    The series you want will be the one that physically matches the mounting requirement - presumably the radial ones. Low ESR and the 105C spec are all that you need to know along with the value/voltage but, as mentioned, those aren't entirely critical to the task, especially in a simple SMPS of...
  15. kellys_eye

    Diy multi bank battery charger

    The circuit you link to.... As it stands it is limited to a 2A maximum charge current but if you look at the L200 datasheet (there's a link in that article to one - see page 8/12 fig 24) where it shows how to use bypass transistors to increase this to whatever you require. As wired the circuit...
  16. kellys_eye

    Static On My Radio

    Energy saving lights (CFL or LED) are often culprits. You have to go around and systematically switch equipment and lights off to locate the source. There will be 'many' sources though but you'll eventually find the one(s) that are particularly problematic and can either change them to...
  17. kellys_eye

    Recapping a PSU -choosing the right replacement caps

    Yes 'N'ichicon is what I meant lol. The values aren't as critical as you'd think. Many electrolytics have a basic tolerance of +10/-50% (or some such ridiculous span) so the 'next nearest' value is often a simpler way to go. Only other advice I can recommend is to check the capacitors on the...
  18. kellys_eye

    SRF2978

    Got a schematic of where it's used? What package type is it?
  19. kellys_eye

    Programmable LED driver or DIY circuit

    Do this is a stepped approach (no pun intended). Look to just switch the light strips on/off as the PIRs are activated. When you achieve this part then tackle the 'dimming' requirement as a separate issue. If you break it down to 'switching' and 'dimming' then each individual process is very...
  20. kellys_eye

    Finding the right switch

    The rotary controller you're referring to is an 'encoder' and will require a digital (processor) interface to resolve into the analogue replacement for the original volume control. Whilst it's a potential solution to the OP's needs it may well be far more involved and complicated to implement...
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