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HarryA

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Everything posted by HarryA

  1. Step 1: Are you committed to using to using the TC4420 and 40193? Consider using a circuit like the one below. The direction of current flow through the relay coil depends on which transistor is on. Also if you do not have the relays yet these may simplify your design: https://www.amazon.com/SMAKN-Trigger-Switch-Latching-controlled/dp/B01CN7V0F6/ref=sr_1_20?dchild=1&keywords=latching+relay&qid=1617978673&sr=8-20 What are you using of inputs to the circuit?
  2. There are a couple of videos on Youtube you may find helpful. The first one uses a socket with colored wires while the second one shows the terminals on the back of the switch. In the first one he connects directly to 12 volts while in the second one he claims the LED is 3 to 6 volts and uses a resistor to connect to 12 volts. If you need help connecting to the board I will look at its specifications. https://www.youtube.com/watch?v=nlPj0VL_bGU https://www.youtube.com/watch?v=zd3n8pYFx1g
  3. That is a complex beast! Given: "Each LED output can be off or on (no PWM control), or set at its individual PWM controller value. The LED output driver is programmed to be either open-drain with a 25 mA current sink capability at 5 V or totem pole with a 25mA sink, 10 mA source capability at 5 V." If you are using the PWM control the meter would not show the peak currents to the LEDs. Other then that it is difficult to help troubleshoot something that requires programming.
  4. As the TC4420 accepts logic level inputs and the 40193 output is a logic level why is anything needed between them? Also both only require a single voltage supply (Vdd) for the circuit shown a dual supply would not be required. There are single Vdd supply op amps if you need one. I have a circuit that uses a TC4420 driven directly via a Arduino Uno output.
  5. Are pinball schematics any different than electronic schematics? https://learn.sparkfun.com/tutorials/how-to-read-a-schematic/all
  6. I gather you are looking for a circuit like this one. Do you have any idea what the currents are? Perhaps one could key off the change in voltage at the battery; low voltage turns a transistor on to power a relay.
  7. There is something about pulse transformers dealing with the pulse width. If the input pulse width is two short the current never has time to build up completely do to the lagging current in an inductor/coil. That would look like an impedance mismatch also. If the pulse is to wide current is wasted when the coil is fully energized. For example see https://www.youtube.com/watch?v=vvXbTIqBY4o
  8. Yes you can use a battery as long as it is 6.0 volts. How long it will last will depend on how much current the camera draws. If you are using 4 AA batteries there is good information here: https://www.powerstream.com/AA-tests.htm
  9. Your getting just 3 volts suggest an impedance mismatch between the transformer and the cell. In looking at using automobile ignition coils for high voltage I see a number of videos and articles where they get huge sparks from the coils that I can not get. I feel like you; where is the spark! I am thinking my coil is a dud! See for example: https://www.youtube.com/watch?v=PTt5sM3moqQ There are a number of similar videos there using ignition coils for high voltages.
  10. We know the output voltage is related to the ratio of the number of turns. And the output current related to the inverse of the number of turns. The more voltage gives one more current at the primary so in an ideal transformer the power is the same on both sides of the transformer. But in a pulse transformer is it not the rate of change of current in the primary that gives rise to the change in magnetic flux that produces the voltage? I need to learn more about pulse transformers. I had in mind trying out different frequencies on the automobile coil/transformer but had a problem when
  11. Using the 100 watt bulb and two different ignition coils this is what I got: AC Output(VOM) 1 meg load Input sig. 204 Hz Peak voltage across 7ohms coil type 67.4 v 6.0v 1.84 v std auto ignt. coil 159.8 v 9.68 v 5.44 v 17.4 v 8.0 4.0 - 4.2 v Capacitor discharge coil The std auto coil is a 12 volt
  12. Don't laugh that is an emulation of your circuit. I was thinking that there is not enough load in the circuit with only the coil (the mosfets are acting like switches only off or on) so I started out with 7 watt incandescent lamps but could not get two mosfet to work so I switched to only one; that works well. In the photo at the lower right is an automobile ignition coil and the big black thing is an 80 volt battery (borrowed from my chainsaw). Working up to 13 bulbs (normally 7 watt bulbs) I got 0.571 ma through a 7 ohm resistor. Switching to a 100 watt bulb got 0.594 ma, the IR
  13. I was using the fixed resistors as the simulator dos not have a concept of a potentiometer. Putting the 530 back in an using a combination of two resistors between 30k - 17k to 46k - 1k (where the lower value is to ground) I get good results with 40k - 7k and 30k - 17k but the peak current is 2 amperes for some reason. At 44k - 3k the current is 900ma but the output is down to 50v. I will continue looking at it. If you have a symmetrical pulse waveform say of 1 ampere I gather the rms value of the current is 1 * 0.707 and the rms voltage would be 100 * 0.707 so the equivalent pow
  14. I would think you are not hitting it with enough current. Using a resistor instead of the IRF530 as it is faster to use rather then dorking around with two resistors to simulate a pot. I am using a input pulses that 2.5 ms on and 2.5 ms off at 6.8 volts peak No bifilar coil nor diode in the output: resistor current output capacitor output resistor output voltage 100 1A 1.058 nf 1.16 meg 720 volts 100 1A 0 1.16 1.05 kv 50 2A
  15. New section: For R1(max). Assuming a 8 volt transformer. Vin = 8.0 * 1.4 or 11.2 Taking the min and max to be plus or minus 10%. One would not need a voltage regulator if there where nothing to regulate. Vmin = (Vin - 10%*Vin) - (2 * voltage drop across the two diodes). Typically 0.7v each. And Vmax = Vin + 10%Vin - (2 * voltage drop). R1max = (Vmin - Vz)/(Izmin + Ib) Izmin is found from the zener data sheet; typically 10 ma. What happens at Vmax? R1max = (Vmax - Vz)/(Izmax + Ib) Where Izmax is the only unknown here. Izmax must be within the maximum curr
  16. Part one: Starting on the right: the load resistor minimum would be Ro = Vout/Iout. As the transistor is used as an emitter follower the output will be near a voltage gain of one. For the Zener diode and Vout of 6.0v you must allow for the voltage drop Vbe (Vb to Ve) of 0.6 to 0.7 volts. So Vz = Vout + 0.7 volts or a Zener with a voltage at or above wanted Vz. R1 supplies current to the base of the transistor and the Zener. The current input into the base of the transistor can be found using the hFE (the forward current transfer ratio) or current gain of the transistor. Ib * hF
  17. In the simulator (with 100 ohms between the PSU and the coil and 1 ohm resistor in the source lead of the ITF840) the output is about 1.2kv peak with or without the 1.164 meg resistor. With the 1.058nF capacitor it drops to about 750v and with the 5.18nF it drops to about 450v. The current through the secondary coil is +29ma to -42ma peaks. The current through the primary is 0 to 1.8 amperes peak. This is with a 100 ohm resistor between the PSU and the coil. At the 1 ohm resistor in the source lead of the ITF840 it shows 1 ampere peaks. I found an ITF840 spice model. If you
  18. Can you measure the resistance of the cell? Possible it got comtaminated. Also knowing the size of the electrodes and their separation in water one could get a first order approximation of the cell's capacitance.
  19. I must admit the more I look at the circuit the more confused I get. Why the negative rail connects to the TL081 is beyond me. Why it connects to the 30 v rail when it is only rated 18v max is a mystery to me also. Also there are many different up grades to the circuit I gather; for example I have this one I got from somewhere. Note the differences in connections to negative rail and a voltage regulator not the zener diode. Also if you search for "0-30 V PSU not workingy" on the internet you will find this PSU has been beaten to death numerous times on various forums includin
  20. What happens when you connect the load? You may try to connect a small capacitor across the output if you have one that has the required voltage rating. The last trace maybe as good as you can get. I will try adding distributed capacitance to the windings to see if that produces similar results in the simulator.
  21. Putting just the front end into the simulator. The labels in large print map back to the schematic. Using a 4.7 volt zener simulator doesn't have a 5.1 zener. In these traces the green is the voltage on the negative rail and the yellow is between D6 and R3. In this one the green trace is between D5 and D6 while the yellow trace is the current through R2. And this one is with C3 disconnected. voltage at the negative rail.
  22. What is a Nilma Radio? Are these band pass filters used in the antenna input used when selection one of two radio bands? If you have both types of inductor cores why not use them? As you are on the upper limit of the T37-2 cores and the T37-6 cores (lower limit) do not need to go below the upper limit of the T37-2 cores for the higher frequencies.
  23. As a first try the circuit below has a transformer with the primary of 1.8mh and 0.1 ohm while the secondary is 720mh and 150 ohms. The inductance is related to the number of turns squared ratio: 25^2 to 500^2 = 625/250000 = 0.0025 thus ( 0.0025 * 720mh) = 1.8mh So your guess is a lot better than mine would be. For input the pulses are 2ms on and 2ms off for a period of 4ms. Amplitude is 8 volts. The out put would make a good TENs device for an elephant.
  24. I set the browser to display the links in large bold fonts. As the first page is all links that did what I wanted to do.
  25. What are you using for input pulses? Any idea what the inductance of the primary and secondary windings of the transformer are? Else does anyone have a good guess what they may be? I have never used inductors enough to get any concept of what transformer inductance like that would be. I can run the circuit in the simulator if you like.
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