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HarryA last won the day on April 11

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About HarryA

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  • Birthday June 23

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    USA, Pennsylvania, Susquehanna Cty, Forest Lake
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    Canoeing, woodworking, electronics, and gardening.

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  1. If you look around on ebay or amazon.com for "audio amplifier board 5 volts" you may find something that would be helpful. Like: Icstation PM2038 2X5W stero audio amplifier board 5v USB powered adjustable volume. They are quite inexpensive. https://www.amazon.com/PM2038-2X5W-Stereo-Audio-Amplifier/dp/B01NABJTDJ/ref=sr_1_36?crid=2KDQ8EUT857T7&keywords=audio+amplifier+board+5v&qid=1558736268&s=gateway&sprefix=audio+amplifier+board%2Caps%2C184&sr=8-36 Sorry I can not be more helpful.
  2. BMS 18650 chargers are quite inexpensive off Ebay if you are not big on rolling your own. https://www.ebay.com/itm/3S-20A-12-6V-Li-ion-Lithium-18650-Battery-Cell-Circuit-BMS-Protection-PCB-Board/122183528602?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D56826%26meid%3D93e40678e3dd4abe9ac93405e5253fca%26pid%3D100005%26rk%3D5%26rkt%3D12%26sd%3D253289010740%26itm%3D122183528602&_trksid=p2047675.c100005.m1851
  3. If you search on YouTube for " 3 phase electric motor control" you may find some information that maybe helpful.
  4. HarryA

    Rc car

    Perhaps the chip is over heating with to much current draw? Try connecting only two motors to see what happens. For the l298n chip itself: For the IO Peak Output Current (each Channel) – Non Repetitive (t = 100ms) 3.0A –Repetitive (80% on –20% off; ton = 10ms) 2.5A –DC Operation 2.0A TOTAL DC CURRENT UP TO 4 A
  5. I do not see your question; perhaps I am missing something
  6. 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
  7. 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, say 100/1000 Using Ip = Is(Ns/Np) I am not clear which way you are going here. 0.3 amperes = 1 ampere (Ns/Np) Ns/Np = 0.3 say 180/600 or: 1 ampere = 0.3(Np/Ns) Np/Ns = 3.33.. or say 600/180 For power: Pp = Ps at 100% efficiency. Ps = n * Pp where n is the efficiency factor. n between 65 and 99 percent For 50 watts at the secondary and 75% efficiency the primary power would be: Pp watts= Ps/n = 50 vac/0.75 = 66.66... watts. For Impedance: Zp = Zs(Np/Ns)^2 To connect an 8 ohm speaker to a 400 ohm amplifier: Np/Ns = (Zp/Zs)^0.5 = (400/8)^0.5 = 7 I must confess I have no idea how many windings real transformers have; do not go by my numbers. Somewhere I have a book that has information on designing transformers if you need more info I will try to find it.
  8. 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.
  9. 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 words OUT perhaps? P1 and P2 look odd; they have the potential of shorting the inputs. At P2 with the wiper all the way down the input would be shorted circuited.
  10. I used: bluetooth camera for iphone also see: https://techpp.com/2013/04/17/bluetooth-cameras-connect-smartphone/
  11. 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
  12. 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.
  13. 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!
  14. Power Strip with USB, Surge Protector Smart 3 Outlet and 4 USB Port Charger with 5ft Extension Power Cord 1250W 100-240V https://www.amazon.com/Protector-Extension-100-240V-Portable-Transformers/dp/B07KGPFHYC/ref=sr_1_9?s=electronics&ie=UTF8&qid=1548959567&sr=1-9&keywords=surge+protectors+for+computers I worked with a power supply that was 900 amperes and 8 volts; this would not work for that
  15. This maybe helpful: How to make an IR blaster: https://www.instructables.com/id/How-to-Make-an-IR-Blaster/ and an amplifier https://www.amazon.com/Geekroom-Headphone-Amplifier-Rechargable-Computers-Black/dp/B07F1JS4JV/ref=sr_1_21?ie=UTF8&qid=1548463071&sr=8-21&keywords=cell+phone+audio+amplifier This is an old question but it maybe helpful to someone in the future.
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