I have put the circuit on a PCB as close to what Nelson has. I had to move the switch input signal to "outside" the E1 bulb, so direct on the input voltage as it kept on blowing to bulb during start (switch on). With the fixed 2 base resistors (330 and 3.9K parallel, so 303 ohm) i could not get it to oscillate without shorting the output, so i replaced them with a 500 Ohm potmeter. Now after some tuning i got it running both without shorting the output as with shorting the output. But the signal levels do not match the ones shown by Nelson. I have 500Vpp on the emitter unshorted (192Vpp shorted) and 450V dc out unloaded, so way higher voltages. Also input current is double that of Nelson with 70mA @ 24V. But the good news is that when shorting the output i have much more current then with the breadboard version and the input current drops when shorting like Nelson showed. Its 37mA out when shorting at 38mA in (so input current halfs). Anyway, i blew up my matching input bulb, so have to replace it tomorrow to see the difference in lights. Video here: https://www.youtube.com/watch?v=t-orpEbEzWY&feature=youtu.beQuestion; is the switch input really behind the E1 bulb like the diagram shows or is it directly on the input voltage? Lateron i found out that when i lower he input voltage to 15V, the input current drops to 30mA and the unloaded output voltage is 240V. When then shorting the output the input current drops to 22.1mA and the output goes to 22.4mA! The potmeter value was set to 120 Ohm during the tests. Itsu
« Last Edit: 2020-05-10, 21:27:34 by Itsu »
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