Quote:
Originally Posted by Mario
Hi Ewhaz,
The transistor part number in the book is wrong and should be BD243C, another mistake is pin 4 and 5 of the opto, the connections are inverted.
I have tried running the oscillator from a 555 instead of the trigger wire, it works too, but for every freq you are tuning to you have to readjust the duty cycle to get the best signal for that freq, finally I found that the trigger winding does this automatically and even better  , so I went back to the winding.
regards,
Mario |
Well, I have the right transistor thankfully, but I did notice the difference after you pointed it out. Maybe this was enough distortion so that the powers that be would leave it alone, who knows?
But yes, changing the duty cycle on a 555 would be a real pain. I'm assuming that the higher the frequency the longer the on cycle would have to be in order to allow it to reach saturation before the field could be allowed to collapse. Most likely this would require a lot of tuning. Still, at least its an option to explore later on circuits with different applications.
Still, what about the capacitor? The voltage on it is not listed for the charging side capacitor (not the timing). From what I've read, you have to be careful not to 'hit' the battery too hard, or it will cause a cascade effect that will cause the battery to explode, or at the very least be damaged. Is there a correlation between the type of battery to be charged and the maximum voltage that the capacitor can deliver safely?