All:
This is my first post here. Member Volenti over at Audiokarma suggested I post this question here to get help.
I wish to build a circuit to help my son's science project. I need to built a circuit similar to the attached PDF. I wish to charge a cap from a high voltage source then discharge it through a transformer and accomplish the switching of the cap with transistors. I need the speed of transistors to get to the needed 600 to 1000 switchings per second the project will require. My problem is that I just can't figure out what the circuit to the left of the gates needs to look like. I've managed to determine that the upper transistor needs between 250 and 255 Volts on the gate to turn on with enough current to provide the charging speed I will need. The lower one needs about 5 volts of so to turn on. My original plan was to use something like a 555 clock output to control the switching. A logic chip of nand gates could give me logic highs when I have logic lows out of the clock to get me the high on one transistor and low on the other. What I am stuck on is how to get the 250+ volts on the gate of the upper transistor when I have only 5 volts or so out of the logic circuits.
Any help or ideas would be appreciated.
Thanks
Shelly_D
P.S. I do not have these transistors already so I am not wedded to them. If something else will do better service I'm all ears. Also you should know this is my first build with transistors (been a vacuum tube guy on previous work) so I kind of need to be taken by the hand and led to the solution.
This is my first post here. Member Volenti over at Audiokarma suggested I post this question here to get help.
I wish to build a circuit to help my son's science project. I need to built a circuit similar to the attached PDF. I wish to charge a cap from a high voltage source then discharge it through a transformer and accomplish the switching of the cap with transistors. I need the speed of transistors to get to the needed 600 to 1000 switchings per second the project will require. My problem is that I just can't figure out what the circuit to the left of the gates needs to look like. I've managed to determine that the upper transistor needs between 250 and 255 Volts on the gate to turn on with enough current to provide the charging speed I will need. The lower one needs about 5 volts of so to turn on. My original plan was to use something like a 555 clock output to control the switching. A logic chip of nand gates could give me logic highs when I have logic lows out of the clock to get me the high on one transistor and low on the other. What I am stuck on is how to get the 250+ volts on the gate of the upper transistor when I have only 5 volts or so out of the logic circuits.
Any help or ideas would be appreciated.
Thanks
Shelly_D
P.S. I do not have these transistors already so I am not wedded to them. If something else will do better service I'm all ears. Also you should know this is my first build with transistors (been a vacuum tube guy on previous work) so I kind of need to be taken by the hand and led to the solution.
