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Everything posted by HarryA

  1. or cleaner: String DisplayString = " "; //a blank string int percent1 = 0; int OldPercent = 0; void setup() { // Serial.begin(9600); //testing } void loop() { if( OldPercent != percent1 ) //do not scroll needlessly { //previous string - set the cursor to second line LCD.setCursor(0,2); LCD.print(DisplayString); //move previous line down //set the cursor to for new first line LCD.setCursor(0,1); if (percent1 > 50) { //new string DisplayString = "Moisture S1 : " + String(percent1) + "%" + " Irrigaion sistem ON"; } else { //new string DisplayString = "Moisture S1 : " + String(percent1) + "%" + " Irrigaion sistem OFF"; } //set the cursor for new first line LCD.setCursor(0,1); LCD.print(DisplayString); //new line to top of the LCD OldPercent = percent1; //set new percent } } //end loop the first "set the cursor for new first line" code is redundant; I can not see how to edit the code
  2. Perhaps: String DisplayString = " "; //a blank string int percent1 = 0; int OldPercent = 0; void setup() { // Serial.begin(9600); //testing } void loop() { if( OldPercent != percent1 ) //do not scroll needlessly { //previous string - set the cursor to second line LCD.setCursor(0,2); LCD.print(DisplayString); //moves previous line down if (percent1 > 50) { //new string DisplayString = "Moisture S1 : " + String(percent1) + "%" + " Irrigaion sistem ON"; //set the cursor to for new first line LCD.setCursor(0,1); LCD.print(DisplayString); //new line to top of the LCD OldPercent = percent1; //set new percent } else { //new string DisplayString = "Moisture S1 : " + String(percent1) + "%" + " Irrigaion sistem OFF"; //set the cursor to new first line LCD.setCursor(0,1); LCD.print(DisplayString); //new line to top of the LCD OldPercent = percent1; //set new percent } } } //end loop
  3. "Could a capacitor smooth the frequency? " If one does not know what is wrong with the system then one can not know what the affects of a capacitor would be. you have a 12 5kw diesel generator the generator outputs 120 or 240 volts at 50 or 60 hertz. the generator supplies the mains that has numerous outlets on the boat. the generator output is stable until you turn on the ac unit. with the ac running the voltage at the various outputs are no longer 50 or 60 hertz but varying in frequency 6: adding any load to an output corrects the problem. Is that correct?
  4. 48 volts is above the absolute voltage for this voltage regulator: 35 volts maximum:
  5. In that type of air conditioner the input ac voltage is converted into dc via a power supply. The dc voltage is converted (inverted) into variable frequency ac. The frequency depends on the demand on the unit. A microcontroller samples the ambient air temperature and adjusts the speed of the compressor motor via the frequency of the ac applied to the compressor motor. Invert versus convert is interesting: Inverter - dc to ac converter - ac to ac (transformer, etc) converter - dc to dc (potentiometer, etc) power supply - ac to dc
  6. see: http://starseedsportal.org/tag/stephen-dickens-magnesium-water-copper-battery/ plus other sites; search on "stephen dickens water battery" Also see Voltaic pile at: https://en.wikipedia.org/wiki/Voltaic_pile
  7. I have not used varistors but not letting ignorance slow me down. The V20E14AUTO is a 16 volt MOV. Voltage Rating DC: 16vdc Varistor Voltage: 22 volts this is where the varistor starts to conduct at 1 ma. Varistors draw some small current always Clamping Voltage: 43 volts the voltage any spike is truncated to. Peak Surge Current: 20 amperes. Surge Energy Rating: 28 joules. 28 watts-1 second, 56 watts-500 ms, etc Unlike Zener diodes that fail as an open circuit varistors fail as a short circuit so in some cases a fuse is used with them. Most likely on the larger ones.. see: https://www.mouser.com/ProductDetail/Littelfuse/V20E14AUTO?qs=%2Fha2pyFadugE%2FoOLoA7J9TCvi67Mtc%2F%2FOVMAqZDk45RR%2F7GD1QKNkA%3D%3D or: https://www.digikey.com/products/en?mpart=V20E14AUTO&v=18 That is my best guess; perhaps someone else has experience with varistors? "The MagLock Draws 420mA 2 12 Volts, The panels power supply provides 500mA @ 14.3 V " Do you need to reduce the 14.3 volts to 12 volts?
  8. Wikipedia has a well written article on operational amplifier applications. see: https://en.wikipedia.org/wiki/Operational_amplifier_applications#Non-inverting_amplifier
  9. There is information here on Visual Servoing that maybe helpful; particularly the numerous references at the end of the article. https://en.wikipedia.org/wiki/Visual_servoing If you look at a bmp file of a smd image like this one (I could not find an image of the bottom of a smd). You can see the white background as FF FF FF and one scan line across the component highlighted. So in theory one could find the four corners and calculated the rotation and any x y offset. In bmp files the image is inverted. If you only need the rotation then only part of one edge would be required to calculate it I believe. smd compoint.bmp
  10. You may find some useful information here. If you need more help come back here. https://github.com/openpnp/openpnp/wiki/Setup-and-Calibration%3A-Bottom-Camera-Setup I worked for a company that made PnP and Through-hole machines but I only worked on the Through-hole machines.
  11. what is the replacement for the d13005ed? Perhaps the MJE13005G ? The data sheet is online. The MJE13005G from China see: https://www.ebay.com/itm/5PCS-X-UTC-MJE13005G-C-TM3-T-TO-251-I-PAK-NPN-Vceo-700V-Ic-4A-Transistors/333530195913? hash=item4da7f2e7c9:g:9MgAAOSwr9ReWXce The D23005Ed 20 of them! "20 x D13005ED Transistor TO-220" from China. https://www.ebay.com/itm/20-x-D13005ED-Transistor-TO-220/184022252029?hash=item2ad894b9fd:g:cLQAAOSwOFZdwBIz also see for large list of similar transistors: https://alltransistors.com/crsearch.php?at=Si&struct=NPN&pc=65&ucb=700&uce=400&ueb=9&ic=4&tj=150&ft=4&hfe=15&caps=TO220
  12. HarryA

    Sharp DX-110

    If it is worth 21$ to you. You can always sell it on ebay when you are done with it 😉 https://www.amazon.com/Service-Technical-Information-Compact-Digital/dp/B00KV315WI It's 29.99$ on ebay https://www.ebay.com/itm/Sharp-dx-110-service-manual-original-repair-book-stereo-cd-player/123711246781?hash=item1ccdc3d1bd:g:8RoAAOSwk~NZ2OdD
  13. If you open the unit up and find out what is wrong with it that will give you insight into what the problem is/was. If the problem is on the AC input side it may well be, as you say, a spike from the power source.
  14. I am confused by the circuit. If -v is grounded at connector CN1 then it is grounded at connector CN2 also. If so then capacitors C18,C19, C20, and C21 are grounded on both ends? Thus there would be no 1/2 voltage and +v would be at full voltage off the bridge rectifier? I must be reading the schematic wrong.
  15. the circuit below works in the LTspice simulator and as a prototype: Traces from the simulator: The green trace is the input from the sensor, the yellow trace is at pin 2, and the red trace is the output at pin 3. Note the positive going pulse when the input drops back to zero. That is why the Zener diode is required to limit it. Here it is a 15v Zener diode. The output from prototype the circuit: Here I am using 9 volts as I only have 12 volt Zeners. Here the blue trace is the trigger signal at pin 2 and the yellow trace is the output at pin 3 across a 150 ohm resistor for a relay load. The diode across the relay coil can be any general purpose diode like a 1N007 for example. The output is much wider then I would expect for R4 at 1Megohms and C3 at 1 microfarad. Expected 1 sec. not 1.4 There are numerous online calculators for calculating these values. The values for the resistors are not critical except what you pick for R4: R1: 1000 to 1500 ohms R2; 20k to 30K " R3: 30K to 50K " all work in the simulator.
  16. The problem with the 555 timer is that it is not edge triggered and it is retriggerable. You would like a one-shot that is rising edge triggered. Retriggerible means as long as a moose stands in front of the PIR the 555 would output a pulse; having inverted the output with a transistor. Thus the relay would stay energized. That is okay if you want to make a movie of a moose but not good for one photo. The 74121 is a nonretriggerable and is edge triggerable, that would be a better fit. I will look at your circuit to see if it be used. I am thinking perhaps one could invert the PIR output with a transistor and discharge a capacitor to momentarily pull trigger pin 2 low. What is the resistance of your relay if you already have one? One needs to know how much current it would draw.
  17. HarryA

    Adblock Plus?

    Is there a way to block listings containing Realtek and Ameba using Adblock Plus? I added them to the filter list but it did not work.
  18. That looks good. Good use of the capacitor. If you replaced the DPDT toggle switch with a relay powered of the supply on power failure would it switch to inverter automaticlly?
  19. How fast is an MLX90614 IR temperature sensor? https://www.electronics-lab.com/project/infrared-thermometer-arduino-mlx90614-temperature-sensor/
  20. You need to create a pulse that goes from low to high and back again to low. Like the first pulse B: If you connect a resistor ( say 10k perhaps ) from the pulse in line to ground that will hold it low. Then connect your switch from the pulse in line to the Vcc the supply voltage. When you switch on the switch you create the rising edge like pulse B above. See line 4 below. When you open the switch you get the trailing edge of pulse B above. That is the transition for line 5 below. The function table may differ from this one for the one-shot you use. Remember if your switch is closed longer than the output pulse you create be sure to use a nonretriggerable chip. Analog makes chips of this type also: the LTC6993 family of one-shots. .
  21. The circuit below uses edge triggering so you get an output on the rising edge and the falling edge of a pulse. The SN74LVCIG123 is a surface mount component but there is a throw hole chip; the 74123. The 74123 is a retriggerable monostable multivibrator (one shot). Retriggerable means that the output persist as long as the input is applied so if you switch closure is longer than the output pulse it still remains high. The 74121 is a nonretriggerable version. If you use a two position selector switch that would work; selecting ground or high. Else you may have to use retriggerable monostable to get a real pulse if you use a simple push button; as input to the circuit.
  22. HarryA


    Doing a prototype of the circuit as shown below using a voltage regulator as I have no 5 volt Zeners: I used 1N007 diodes and a LM7805 regulator. Transformer output 13.85 Vac 17.3 Vdc at the capacitors. What I got for ripple voltage at the capacitor was: 536 mvpp with 1523 mfd cap. 140 mv ac with multimeter 288 mvpp with 3005 mfd cap 71 mv 200 mvpp with 4454 mfd cap. 48 mv 140 mvpp with 6050 mfd cap 36 mv
  23. It looks similar to: y[n]=0; for(i=0; i<n; i++) y[n] += x * b; see: http://pdfserv.maximintegrated.com/en/an/AN3386.pdf What language is that? Never seen (long long) before. Perhaps like a double in C ?
  24. HarryA


    The 12 volt transformer supplies a peak voltage of: Vpeak = 12 * square root of 2 = 12 * 1.4 = 16.8 With 16.8 volts into the bridge we subtract 0.7 volts for each diode. As the current passes through 2 diodes for 1.4 volts. Vdc = 16.8 - 1.4 = 15.4 without a load. The actual loaded voltage will be more likely around 14 volts as we will see later with a capacitor and load. I am using 20ma LED here. For the capacitor: ------------------ ripple voltage Vr: Vr = (0.0024) * I/C = 100 mv C = 0.0024 * I / Vr = 0.0024 * (0.120A / 0.10V) = 0.00288 F 0r: C = 2880 micro-farad from Schertz and Monk "Practial Electronics for Inventors" section 11.6 For a Zener diode ------------------ Lets try the 5.1 volt 1N4733A. As 5.0 volt Zeners are hard to find. For the 1N4733A Zener diode the value of Vz is 5.1V and Pz is 500 milliWatts now with a Vdc (dc supply voltage) of 14V the value of R2 will be: Rs = (Vdc - Vz)/Iz Rs = (14 - 5.1)/Iz Iz = Pz/Vz = 500mW / 5.1V = 98mA max. Thus Rs = (14 - 5.1)/98ma = 90.8 ohms Rs = 91 ohms (approx) 91 ohms is a standard. The power/watts into R2 will be: Pr2 = V^2/Rs = ((14 - 5.1)^2)/Rs = (8.9 * 8.9)/91 = 0.87 watts or 2 watts in practice. So with a load of 120 ma the voltage drop across Rs: Vrs = 91 * 0.12 = 10.92 volts ........oops! Looks we only have 14 - 10.92 = 3.08 for the load and the Zener is out of business! Lets try a 1 watt Zener and 5.1 volts: Iz = 1.0 watt / 5.1 volts = 0.196 A or 196 ma. Rs = (14 - 5.1)/ 0.196A = 45.4 ohms or 47 ohms standard Voltage drop across Rs at full load: Vrs = 47 * 0.12 = 5.4 volts; Or 14v - 5.4v = 8.6 volts for the Zener to chew on. The power/watts into R2 will be: Pr2 = V^2/Rs = ((14 - 5.1)^2)/Rs = (8.9 * 8.9)/47 = 1.685 watts or 2 watts or better in practice. Next we can run this through the simulator and see what it looks like. (to be continued).
  25. HarryA


    Are you interesting in designing a circuit using mathematical equations or are you interested in building a power supply using proportional engineering (as a 6.3 volt filament transformer should work)? Proportional engineering is the way I build most things. Are you looking for help here?
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