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  1. Sunnysky

    Voltage Converter or Not?

    the board looks as though it already has it with 10uF tantalum and diode, no? I presumed if an Arduino was being used, it would have a separate supply =7V and onboard 5V so this board has a dedicated LiPo cell with a common ground.
  2. Sunnysky

    4066 switches leaking in sample and hold circuit?

    what sample time ? or is this just a "track and hold circuit" If using just a simple SPST switch, I would use 10k with 1uF to de-glitch contact bounce, but not critical. This would hold in 10ms .
  3. Sunnysky

    Voltage Converter or Not?

    I agree, that's what I meant,moto clamp to internal regulated voltage on Rx chip. Perhaps series R 100-1K as source impedance will be <100Ω from CMOS driver @5V. use twisted pairs if > 1ft. 2) Normally a LiPo can supply the 3A burst during Tx if charged.
  4. Sunnysky

    A lot of old electronics (NiB), and very little knowledge about it.

    finding a customer is the hard part
  5. Sunnysky

    Voltage Converter or Not?

    No converter needed. Input 1 LiPo cell voltage with charger attached. Serial port 3.3 V logic uC interface. If using >3.3V logic, then a Schottky .power diode clamp to 3.3V needed for Rx data.
  6. Sunnysky

    A lot of old electronics (NiB), and very little knowledge about it.

    Without traceability, these parts are unsalable for Military spare parts orders in Ohio, where centralized puchasing is done only by registered users. Otherwise, these appear to be parts with zero demand and a retail replacement value of < 1$ for caps and resistors, magnetics are too custom and...
  7. Sunnysky

    Single led vumeter using LM311 comparator at the output amplifier?

    There were two (2) implied questions. Compatibility and Rhythm response desired. 1) For loading on amp or speAkers distortion , anything> with >1k input impedance will have no perceived effect, perhaps less. For sensitivity, gain/attenuation control is needed from speaker, but not from Line...
  8. Sunnysky

    Miniature electrets - how to use?

    http://www.talkingelectronics.com/projects/TheTransistorAmplifier/TheTransistorAmplifier-P1.html#Connecting
  9. Sunnysky

    Single led vumeter using LM311 comparator at the output amplifier?

    I already told you in EDA , it won't work. You need to demodulate the signal with a peak detector and signal conditioner for the. desired response.
  10. Sunnysky

    Playing with valves

    Irfanview makes graph snapshots easy Alt+PrtScn to capture the window Ctrl+V to paste into irfanview Draw a rectangle then either Ctrl+Y to crop or Ctrl+C to copy then Ctrl+V to paste here With practice it takes me 15 seconds using a pinned shortcut to i_view in the taskbar. Paste only works...
  11. Sunnysky

    Miniature electrets - how to use?

    You can use CMOS HEX inverter's as an audio amplifier then with diodes, a peak detector, a Schmitt Trigger and a one shot all in one chip or use an Op Amp, transistor and a 555. But the electret specs say the operating voltage is 2V drawing 0.5mA max from external pull-up Rs. The audio is...
  12. Sunnysky

    Peltier

    Peltier devices can be used for RF, medical imaging , radar transmitters etc, where massive cooling and low thermal resistance is critical. They can also be used to cool semiconductors in expensive production testers that maintain a temperature of 25'C when tested, regardless of D.U.T. power...
  13. Sunnysky

    Powering 104 LED's from Molex connector, possible?

    IF you ever need 16~20 Cd 5mm LED's, I have a box of excess stock for one client. 300 per bag. x 50 bags It was a custom order for tight luminance , 4000-4500'K , ESD protected. Each batch of binned parts turned out to be within a few mV of each other, not by spec, just the result of high...
  14. Sunnysky

    Powering 104 LED's from Molex connector, possible?

    Not quite. The LiPo cells have a much lower ESR (<0.1Ω) than the 5MM LEDS (~15Ω), However when LED's exceed their rated current, the exceed a junction rise of 30'C with a rate of 24'C/100mW Thus 30 parallel 5mm LEDs is now 0.5 Ω so the single resistor for the group reduces the risk of all...
  15. Sunnysky

    GPS NMEA, Failover Circuit upgrade attempt.

    Not sure which model you have, but they all have a Loss of Signal or LOS status signal internally, some external. That would make it a lot easier if that was accessible.
  16. Sunnysky

    Shaft help

    yes 6mm threaded panel fasteners are used with 5mm shafted pots
  17. Sunnysky

    Usb car radio

    electrostatic discharge. is that your solder splash?
  18. Sunnysky

    optical character reader and scanner

    OCR works on raw raster scanned images or ones converted from compressed files, but samples per character (dpi) must be very high and high quality for low error rate.
  19. Sunnysky

    Passive sign convention

    Both 20V and 40V absorb power (+) not (-)
  20. Sunnysky

    GPS NMEA, Failover Circuit upgrade attempt.

    Is this just to compensate for time of day clock drift without Internet access? Or some other purpose? The RTC can be made more stable if you want... perhaps easier to handle LOS conditions on GPS.
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