|
I built an rf single stage transistor rf oscillator, tank cct using 15 turns on a ferrite toroid, connected to collector, with a single turn coupling link to the base. Powered by a 12 v transformer supply. It takes a few flicks of the off/on switch to power up. (Mystery no 1). Then I replaced the power supply with a 12v car jump-start battery. Refuses to power up. I bypassed the off/on power switch, and tried applying 12v to the 12v power rail manually with a lead connected to the 12v car jump-starter, repeatedly pressing the 12v lead to the cct board 12v rail. Nothing. Incidentally, I had also placed a capacitor across the 12 V supply, which killed the oscillations immediately. Got rid of the capacitor. Still with the car jump-starter, I tried manually pressing the NEGATIVE lead to the cct board 0v rail, and after a few presses IT STARTED! Back with the original power supply, I placed a CRO across the power supply to see if there was some strange glitch in the 12v supply when I switched it on. IT WOULD NOT START with the cro connected across the 12V rails! I am mystified. I don't guess anyone here might have a clue about this. Seems there is something in the original power supply that is critical to oscillations starting up. |
November 23, 2023 |
|
Also seems to depend on the manner of switching the power on. |
November 23, 2023 |
No answers yet. Contribute your answer below!
You must log in or create an account (free!) to answer a question.
Anyone can ask a question.
Did you already search (see above) to see if a similar question has already been answered? If you can't find the answer, you may ask a question.
CircuitLab's Q&A site is a FREE questions and answers forum for electronics and electrical engineering students, hobbyists, and professionals.
We encourage you to use our built-in schematic & simulation software to add more detail to your questions and answers.
Acceptable Questions:
Unacceptable Questions:
Please respect that there are both seasoned experts and total newbies here: please be nice, be constructive, and be specific!
CircuitLab is an in-browser schematic capture and circuit simulation software tool to help you rapidly design and analyze analog and digital electronics systems.