I love to apply my knowledge and common
sense to get "things"
work. I am an experimentalist and love to tinker with laboratory
equipment. I also repair my own bike and car.
High Vacuum System at Clemson 513
Ultimate Vacuum -
High Vacuum Pump - Pfeiffer TPH 170 controlled with TPC 310, Turbo
Backing Pump - Alcatel, Dual Vane Rotary
Pressure Sensors - Ion Gauge,
Mass Spec -
UV Window -
Viewing Window -
Baking Oven - Yes
Feed Through -
Mechanical Motion -
Other high Vacuum systems : MBE System, High Vacuum System at 509
Rhodes Hall, High Vacuum System at 22 Riggs Hall.
- Coming up soon!
Molecular Pump's Controller Repair
- We successfully repaired the
controller, TCP310, that controls the turbo molecular pump, TPH170.
Both these were manufactured by Pfeiffer Balzers. We debugged all the
boards and found that the problem was with the controller board. Once
we isolated the controller board, we tested it independently using a
separate power supply and found that a tantalum filter capacitor on the
board was damaged. The capacitor was shorting the supply to ground and
thus preventing the controller from starting up. Once the bad component
was found, the capacitor was replaced, which allowed the controller to
Brief explanation of how to find a short component in a PCB without
yanking out all the components! - We identified the faulty (short)
component on the PCB by sprinkling a fine powder of Benzophenone all
over the problematic circuit board, especially over the components
which you expect to fail. You can see the powder melting on the
component that is shorting the supply to ground and generating
significant amount of heat. Other compounds with similar melting points
can also be used if they are safe to handle and easy to clean off.
Depending on your specific condition and ambient temperature, other
chemicals may prove to be more useful. However, Benzophenone (melting
point around 45º Celsius) worked very well for us. While using
this method, make sure to set a sensible current limit and maximum
voltage depending your specific requirement. Thanks to Dr. Kelvin Poole
for coming up with the chemical-sprinkling idea. Electronic technicians
at Clemson loved the way we used the low-cost method to find out the
Tantalum Capacitor Research
Funded by KEMET Electronics Corp.
I work at the Micro
Electronics Characterization Lab at Clemson University with Dr.
William R Harrell.
- Understanding the Dielectric Breakdown Mechanism in Tantalum -
- Polymer based capacitors.
- Measuring leakage currents and modeling leakage currents at the
MS Thesis Investigating
currents in polymer tantalum capacitor
IEEE SoutheastCon 2010 Paper Observation
the Poole-Frenkel Effect in Tantalum Polymer Capacitors
- Funded by National Science Foundation
I work with Dr. Lawrence Murdoch on
- Analyze noise in Displacement Measurement systems - LVDTs, DVRTs
- Build Lightning Protection for systems on the fields/wells.
- Design capacitive high resolution displacement/pressure sensors.
Using an old thrown away car stereo as an amplifier
Total cost < $10. Basically, you want to use the amplifier in the
stereo to amplify signals from your computer's audio port. Newer models
have a built-in "AUX" plug which is great. Earlier steroes did not have
it. Here is how to feed in your signals in to the earlier stereos. Disclaimer:
This might not work with all models.
Car stereo was the factory supplied model in a Nissan.
Sharp Speakers with built in woofer and tweeter. Rated power - 50W each.
Here is how to do it (very
- Remove the cassette playing box from the stereo set carefully.
- On the "tape box connector" on the main board find - Left, Right
and Ground. Or check the data sheet of the amplifier IC - the one with
a big heat sink and see which pin goes where.
- Adjust internal pots on the main board which are marked as "FM
Vol" or "FM SD" to mute the FM signals that are picked up by the FM -
- Use required power supplies to power the stereo set - there are
pins behind the radio to which you can connect.
- Turn ON the stereo and hit the FM button. The device will amplify
the signals that you feed in from your computer because you killed the
- If you hear signal from your computer and an FM channel or noise,
it probably means you have not adjusted the right pot on the main board.
- You might want to attach a small fan to cool the amplifier chip
if you have removed the heat sink.
For me, its been working great for 8 months now!