Search results

Search Forums New Posts
  1. dave9

    what motor

    The easiest would probably be a mains AC powered, synchronous direct drive geared motor, similar to what is used on microwave turntables or heaters that oscillate. They come in various RPMs, I'd think you would want one of the slower versions like possibly 2-3 RPM? As you might imagine, the...
  2. dave9

    Powering Electronic Match

    What do you mean by "does not work when shorting 9V's in series"? Do you mean you have multiple 9V batteries in series or that you have multiple rocket igniters in series on a single 9V battery? It reads like you mean multiple 9V batteries in series but that should work, while it wouldn't...
  3. dave9

    How to create dll file

    This is off topic for the entire forum. Even in this category it is not microcontrollers, programming (them) or IOT. I'm not trying to be a policeman here, just recognizing that this is like posting about how to cook lasagna in a gardening forum. In other words, random chance might result in...
  4. dave9

    replacing a relay - need help with pinout

    https://www.mouser.com/datasheet/2/307/en-g8he-267580.pdf This is the datasheet for your old relay. You can see the diagram on it, indicating pins 1 and 2 are the coil, corresponding to #85 and 86. Yes your screencap is correct. Pin #4, if it is/was present at all, would be the normally...
  5. dave9

    Mounting Multiple PCBs in Rough Environment

    I would not use adhesive standoffs nor hot glue, would passively cool the box and it would be warm to hot inside. Moisture is always a concern, why grass sticks to decks and decks rust out. Sometimes you may (I do in spring) even have to mow when the grass is still wet because it's the best...
  6. dave9

    Mounting Multiple PCBs in Rough Environment

    Perfboard is a nightmare for vibration resistance. If you go that route, pot the entire circuit (potting compound is like an epoxy filler to great a big impervious brick). Really, any route you go, you will have a more rugged system with it potted, but I would use only solid capacitors, no...
  7. dave9

    12V power supply

    With long (garden) power runs you are better off keeping voltage higher, current lower. You'll drop less voltage over a distance and can use a higher gauge, thinner less expensive wire IF you use buck regulators at each load rather than linear which do not reduce current at all. If anything...
  8. dave9

    replacing a relay - need help with pinout

    This makes no sense. You do not want to alter the relay box so it takes nonstandard relays. Just buy the right relay already. They're about $11 each on Amazon, etc. If you live in a 3rd world country where any parts are seized by pirates and all parties executed, so this is your only...
  9. dave9

    Schematic for the philips BT100 bluetooth

    800x resolution may be so low that it won't even show separate PCB traces. Your best bet is save it as lossless PNG (unless your camera already JPEG'd it then leave it as is) then just link here to it on imgur or elsewhere.
  10. dave9

    12V power supply

    I too would pick a larger cap value than 100uF, but I'd expect the regulators take care of ripple and it's probably a high (average, the regulators being linear will be dropping less voltage at the low points in the ripple) output voltage because the transformer is rated for much higher current...
  11. dave9

    12V power supply

    This is a common theme, "I want to use parts I have which aren't right for the job". Do you have other parts that are better? Like a 5V USB phone charger then put a 3.3V LDO regulator after it? Do you care about efficiency? Anything you do starting with a 12VAC transformer, will lose a...
  12. dave9

    Schematic for the philips BT100 bluetooth

    Upload the pic to an image sharing site like https://imgur.com/upload Post a link to the page or embed it in your post.
  13. dave9

    Schematic for the philips BT100 bluetooth

    ... and yes it stops charging when the battery is full. Ideally instead of the example ebay link I posted, I'd keep looking until I found one with mounting holes on the PCB, which would make it more straight forward to use standoffs to attach to an L-shaped bracket to screw or rivet to the...
  14. dave9

    Schematic for the philips BT100 bluetooth

    You can search ebay for micro USB Li-Ion charger. Here is one example: https://www.ebay.com/itm/Micro-USB-Lithium-Li-ion-18650-Battery-Charger-Module-Charging-Board-Protection/123275109046 Since your USB (5.0V) input is higher than a single cell's voltage, you don't want one called a "boost"...
  15. dave9

    Tascam us2x2 headphones knob problem (volume)

    This is old gear you bought used I presume? Maybe dried out grease on the portion of the pot travel seldom used. You could use a multimeter on the pot pins to determine if the resistance between the wiper and either end of the conductive element varies as it should with rotation of the knob...
  16. dave9

    SCALE MODEL LEDS FROM AC POWER SOURCE

    USB phone chargers are not polarized, remember it's an AC input, and are a regulated output, but no if the lights' spec is correct and they take a wide input range of 4.8V to 9.0V then you don't need true regulation per se, would just need the resultant voltage to fall within that range...
  17. dave9

    Schematic for the philips BT100 bluetooth

    Provide a good picture of the PCB and indicate whether the side of the mUSB socket with diagonal edges was facing up away from the board, or down against the board. A schematic probably is not needed because it uses a standardized mUSB socket to charge, but with a good picture of the board...
  18. dave9

    SCALE MODEL LEDS FROM AC POWER SOURCE

    Contact the seller (or manufacturer) to find out the total current draw. You might be able to just repurpose a 5V/USB cell phone charger, not plug it into the wall but rather pop it open (in a vice or clamps or hot knife melt the seams, whichever) pull the wall socket blades off, solder your...
  19. dave9

    Schematic for the philips BT100 bluetooth

    Look at the PCB traces going to the pads the micro USB port was soldered to. Compare to a micro USB socket pinout with VCC on one end and GND on the other. Trace them visually, confirm continuity (0 resistance) with a multimeter. Below, VCC = positive, GND = negative If you can post a...
  20. dave9

    Class AB Power Amplifier Design

    ^ There are lots of analog audio products out there, produced new today, just not so much using discrete amp stages. Just the other day I bought a Ryobi P746 boombox using a pair of YD2030 (TDA2030 equivalent). I wouldn't call analog obsolete. Yes it's less efficient, but power here is...
Top