Nuts and Volts - November 2013

In this column, Russ answers questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist. Feel free to participate with your questions, comments, or suggestions. Send all questions and comments to: Q&A@nutsvolts.com

20 November 2013

■ WITH RUSSELL KINCAID Q & A

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magazine/article/november2013_Q&A.

• Jacob’s Ladder Redux

• Video Monitor Alarm

• Robot Communication More On the Jacob's Ladder

QI have nothing but good news! First, I want to thank Mr. Carlson for his response and advice; slowing the frequency down made all the difference in the world. Second, I would like to thank you! Without your help, Russ, I know I would not have had this much success.

I have not changed the last revision of the circuit I previously submitted. I reengineered the construction of the electrodes making them easier to adjust, and fine-tuned the oscillator. Now, I’m getting a spark to gap 1/8” and climb a 10” set of electrodes ending at a final gap of 7/8”.

There are two coils that I have been working with — both 12V. The first is a smaller twin cylinder type coil; the second is an old can type automobile coil. In my opinion, the smaller coil actually does a better job. It gives a longer more active spark, but it is not as bright.

I want to build a switch circuit. Push the button and it will turn on for 15-20 seconds or whatever, and then turn off. I know I can do this but I have a concern. Additional circuitry will undoubtedly consume more power.

My thoughts are to upgrade to another power supply. Another 12V

with slightly higher amperage: 13.8V at 5A or 15V at 8.4A. I’m not sure if more voltage, more amperage, or if both are the way to go. I don’t want to overdo it. As the circuit stands now, from a 12V 5A supply it delivers 9. 8 volts to the coil — a 2. 2 volt loss. I do not know how to check the current consumption on this circuit. There are several stats I would like to check, but I need to read up on how.

The hex Schmitt trigger has an 18 volt max voltage limit, and the two aluminum electrolytic capacitors are rated at 16V. The other components exceed these voltage limits.