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  1. HarryA1

    Stepdown Transformer Turns Vs. Ampere

    If you are not big on building your own transformer look at: http://www.surplussales.com/homenew.html#Transformers example; 95VA Toroidal Transformer 117/234V to 2 x 15V or 30V at 3.2 Amps at 230 v that  would give you say: 14.7 volts; a fat resistor would remove the 0.7  ;)
  2. HarryA1

    Stepdown Transformer Turns Vs. Ampere

    if: Vp = primary voltage, Ip =primary current, Np = number of primary windings. Vs = secondary voltage, Is = secondary current, Ns = number of secondary winding. then: Vp = Vs(Ns/Np)  and Ip = Is(Ns/Np) example: To transform 120 vac to 12 vac,   Vs = 120 vac (100/1000) = 12 vac Ns/Np = 0.1...
  3. HarryA1

    Relay Rating on Double booster

    I would think if the larger rated relays failed then the smaller rated relays would not last as long. Have you tried looking on Ebay for replacements? I have had good luck recently finding replacement  parts on Ebay. Sorry I can not be more helpful to you; good luck.
  4. HarryA1

    Help interpreting Circuit schema please...

    At the lower left the component would be a 1500/1k5 resistor like the one at the lower right. The LEDs indicate which coil/output is active. At the upper right the symbol looks like a ground off the signal generator. The LEDs are represented  by the white dots on the front panel above the...
  5. HarryA1

    Need Help: Bluetooth External Camera controlled by iPhone app

    I used: bluetooth camera for iphone also see: https://techpp.com/2013/04/17/bluetooth-cameras-connect-smartphone/
  6. HarryA1

    Need Help: Bluetooth External Camera controlled by iPhone app

    Perhaps? To big? " This Fujifilm FinePix digital camera has Bluetooth connectivity for wireless media transfer. " https://www.bestbuy.com/site/fujifilm-finepix-xp130-16-4-megapixel-digital-camera-sky-blue/6204739.p?skuId=6204739
  7. HarryA1

    Power supply circuit ideas

    If you do not need SMD perhaps "The LT138A/LT338A (LM138/LM338) series of adjustable regulators provide 5A output current over an output voltage range of 1.2V to 32V." The LM338 is about 1$ each on ebay.
  8. HarryA1

    Loud Gameshow buzzer

    Search on ebay for "personal alarm switch" most do not have a switch just a pin you pull out. I used one to find the blockage in a drain pipe. They are LOUD!
  9. HarryA1

    over voltages or surge voltages

    Power Strip with USB, Surge Protector Smart 3 Outlet and 4 USB Port Charger with 5ft Extension Power Cord 1250W 100-240V...
  10. HarryA1

    Amplify the smartphone headphone port voltage

    This maybe helpful: How to make an IR blaster: https://www.instructables.com/id/How-to-Make-an-IR-Blaster/ and an amplifier...
  11. HarryA1

    Phone components

    audioguru is correct. But if you are interested in cell phones you may find this site helpful: https://www.instructables.com/id/Make-your-own-cellphone-from-scratch/
  12. HarryA1

    Wanted: Activity Reminder Device

    I would use an arduino microcomputer with an arduino display shield for the display. The best microcomputers are about  22$ down to a few dollars for the ones from China. The arduino display shields are around 10$ or so. The Utlransonic distance measuring transducer senors are less than 10$...
  13. HarryA1

    Changing just the AC Frequency

    One can go from 50hz ac to 12  vdc via battery charger then from 12 vdc battery  to 60hz 120v via a dc to ac converter. see: https://www.bing.com/videos/search?q=50hz+to+60hz+converter&&view=detail&mid=3D9219028DABBB0162A53D9219028DABBB0162A5&&FORM=VDRVRV&ajf=60
  14. HarryA1

    somebody help me

    using "the GIMP"
  15. HarryA1

    Help putting timer on my welder

    Hello, I would think few of us would know anything about mig welders. I gather you want to hot switch the current from the mains to the welder. What current does your welder draw would be a start. You may need a high current relay to do the switching. Like...
  16. HarryA1

    Practical use of voltage divider

    How about 3 terminal adjustable voltage regulators? see for example: https://www.mouser.com/ProductDetail/ON-Semiconductor-Fairchild/LM317AHVT?qs=%2fha2pyFadugRpOCsw7uJG%2fYkcWjLe5SQfHkipQZSRvGAuHf8Q8Z20lpgQCwyK1vllMxUP7WNhWIGj0RAnAK1dQ%3d%3d 60 volts max and 1.5 amperes. Poke around at Mouser...
  17. HarryA1

    how to design a battery jack for unknow phones

    Your " unknown phone " is unknown to us also. One photo is worth a thousand words, two photos are worth two thousand words, etc ;)
  18. HarryA1

    12 volts dc motor

    You need to define this so someone can help you.
  19. HarryA1

    Transformer Watts

    The power required  by the charger would be in the order of: 120 * 0.3 = 36 watts. The 220/240 To 110/120 Volt European Socket Power Converter Step Down Transformer off  ebay.com are rated 100 watts and  not expensive. Order one directly from China; it's just up the big pond from you ;)
  20. HarryA1

    Transformer Watts

    I enlarged the image off the Amazon.com but could not read it :-\ https://www.amazon.com/Black-Decker-LCS1620-Lithium-battery/dp/B01M6TQPY2/ref=sr_1_3/141-0275392-4037060?ie=UTF8&qid=1499813460&sr=8-3&keywords=Black+%26+Decker+LCS1620 ...but ebay.com has a readable image :)...
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