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  1. HarryA1

    Transient Suppression MOV Selection?

    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...
  2. HarryA1

    Introduction to Non-Inverting and Inverting Amplifiers Basics

     Wikipedia has a well written article on operational amplifier applications. see: https://en.wikipedia.org/wiki/Operational_amplifier_applications#Non-inverting_amplifier
  3. HarryA1

    Desktop Pick and Place Machines

    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...
  4. HarryA1

    Desktop Pick and Place Machines

    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.
  5. HarryA1

    Transistor Substitute.

    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...
  6. HarryA1

    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...
  7. HarryA1

    Damaged Power Supply 400VAC/24VDC

    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.
  8. HarryA1

    Half Bridge Driver IR2153

    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...
  9. HarryA1

    555 timer Relay driver with TTL input

    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...
  10. HarryA1

    555 timer Relay driver with TTL input

    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...
  11. HarryA1

    Momentarily switch circuit

    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?
  12. HarryA1

    Fastest Arduino InfraredTemperature Sensor

    How fast is an MLX90614 IR temperature sensor? https://www.electronics-lab.com/project/infrared-thermometer-arduino-mlx90614-temperature-sensor/
  13. HarryA1

    Momentarily switch circuit

    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...
  14. HarryA1

    Momentarily switch circuit

    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 ...
  15. HarryA1

    supply

    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...
  16. HarryA1

    filter realization help

    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 ?
  17. HarryA1

    supply

    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...
  18. HarryA1

    supply

    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?
  19. HarryA1

    Electro shock game boost

    Without a diagram of the circuit it is impossible to help you in spite of the good photographs. It reminds me of the game tossing set mouse traps between players 🤪
  20. HarryA1

    Win 30,000$ helping NASA

    Help NASA explore the moon and win up to 30,000$. See: https://www.herox.com/crowdsourcing-projects/government
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