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  1. M

    Need help testing this circuit

    Someone from another forum told me ''The phototransistor is connected in the wrong place. As shown the gate drive is reduced when light hits the phototransistor. To correct swap the phototransistor with the 100k pot and put a 1k resistor in series with the emitter of the photo transistor such...
  2. M

    Need help testing this circuit

    So the base of the phototransistor is not connected to anything ?
  3. M

    Need help testing this circuit

    Thanks, is there any change to the circuit if instead the phototransistor I use IR receiver diode ?
  4. M

    Need help testing this circuit

    I can't believe this, all I need is that schematic modified with the addition of a testing light led and the schematic posted here and you guys make long posts about electronics theory that's not helping me too much.
  5. M

    Need help testing this circuit

    Thanks for the indications, I saw this schematic on a web page that seemed legit, i guess making a circuit on a diagram you don't understand makes you a moneky...
  6. M

    Need help testing this circuit

    Like this ?
  7. M

    Need help testing this circuit

    I guess use the arrow terminals, I am noobish in electronics but I can build a circuit if I have a correct and complete schematic, so I am here because I need a straight answer for my schematic. I am not even sure if the SCR triggers in a 9V circuit.
  8. M

    Need help testing this circuit

    What do you mean it's drawn unconventionally ?
  9. M

    Need help testing this circuit

    Hello ! I build this Transistor-triggered photogate circuit and it doesn't seem to work. When the light between the emitter and detector diodes is interrupted it should trigger something, can someone tell where to connect a light led in order to test it ? I tried to connect a light led like in...
  10. M

    Transistor-triggered photogate

    Well the flash tube was just an example in reality i need a capacitor discharge into a coil and i don't need additional kilovolts, so like i said i just need to know where in that circuit diagram to connect the capacitor and coil/flash tube. And lets assume the capacitor doesn't need a charging...
  11. M

    Transistor-triggered photogate

    Anyone else ?
  12. M

    Transistor-triggered photogate

    The question was for the circuit diagram attached and I don't see any transformer there, all i need is to add a capacitor and a flashtube, when the infrared light is blocked the capacitor needs to be discharged into the flashtube,(let's consider the capacitor is always charged to 200V so there...
  13. M

    Transistor-triggered photogate

    I have already a charging circuit for the capacitor, but i need it to discharge the capacitor when a small ball is passing and the best way is a infrared detector, the question is where to place the capacitor in that circuit?
  14. M

    Transistor-triggered photogate

    Hello ! I need a photogate to detect a fast passing object and when the light is blocked to trigger a 300V capacitor into a flashtube. The circuit in the image does the job but I have no ideea where in the circuit to connect the capacitor and let's assume the capacitor is already charged.
  15. M

    Capacitor charging

    Thank you!
  16. M

    Capacitor charging

    Sorry I am a bit late... 1. 80ohms 2. 7ohms 3. 500ohms This is with the right side 2k resistor removed.
  17. M

    Capacitor charging

    The resistor at the base of the oscillator is 510 Ohms, oscillator transistor is a SS8850, the battery pack is 6VDC, I charged the capacitor once to 200V only with 2AA 3V, the SCR is a BTA16-800B, both diodes are IN4007, right bank removed resistor is 2k Ohms, the transformer seems to be 1:5...
  18. M

    Capacitor charging

    You guys are disappointing me, no one had the idea to remove the right side 2k resistor I removed it and I charge the capacitor to 300V haven't tried more.
  19. M

    Capacitor charging

    I made a diagram with the coil included, I am almost sure its correct . upload pic
  20. M

    Capacitor charging

    Don't know the resistance of the voltmeter how do I find out ?
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