msd@enh.nist.gov (M. Scott Dewey) (01/09/91)
Greetings! We are trying to build what amounts to a fast high voltage op amp. This device will be used to drive a small penning trap electrode (a 50 picofarad capacitive load) between 0 and 900 volts. In order to minimize the loss of trapped particles during the voltage swing, we'd like the rise and fall time of this device to be less than 10 microseconds. Input for the device will be two low level voltages (each one between 0 and 10 volts) and a TTL signal to switch the output between the two input states. Evidently the gain of the device will be of order 900/9 = 100. We've tried building a circuit that features both an op amp driving a high voltage transister and several filter capacitors, but we've not succeeded in getting a stable beast with a rise and fall time of 10 microseconds yet. None of us is an electronics expert. Is anyone aware of an item of commerce that would do what we want? Does anyone have a schematic that they'd be willing to share? Thanks! -- NAME: Dr. M. Scott Dewey TELE: (301) 975-4843 DIVISION: Quantum Metrology INTERNET: msd@enh.nist.gov USMAIL: NIST (formerly NBS) BITNET: msd@nbsenh Rm. A-141, Bldg. 221 Gaithersburg, MD 20899