Power supplies

1
Power supplies

• Will need power supplies to power
• APDs
• PMs
• Silicon PMs
• Signal amplifiers.

2
Characteristicsof power requirements.

• -12 v  -6v  6 v    1 A each for amplifiers.
• Up to 2kV, positive and negative, from 0 up in at
  least 1V increment for APD, 2-3mA (for 2-3)
• Up to 1.5kV, 10mA for PMT (all 6)
• All of above should have the smallest ripple
  voltage possible (around 1-4 mV)

3
High Voltage power supplies

• Model 556 from ametek-online.com
• Double-NIM crate size, from 10 to 3000V, 2
  output channels.
• 10 mA, output voltage remotely controlled by
  applying from 0 to 6.5V, noise lt10mV
• Not a smooth voltage increments but rather a step
  change on voltage not good for APDs but
  sufficient for PMT
• Current price as of 7/4/2003 - 1615.00

4
HV power supplies

• J4-2P and J4-2N from Matsusada Precision Inc.
• 2P positive 2000V, 2N negative 2kV. Ripple of
  2mV. 2mA output current.
• Voltage regulated by multi-turn built-in
  potentiometer or remotely.
• Recommended for APD.
• Non-standard size.
• Current price as of 3/26/2003 is 252.00 (on
  picture its the left unit)

5
Low Voltage power supplies

• S7-001 HerbachRademan power supply
  (www.herbach.com)
• 0 - 30V (positive and negative simultaneously,
  0.5mV ripple RMS. Current limit 5A.
• Regulated. Dual Panel meters.
• Current price is 238.95

6
APD

• Box design for cooling the APD using the peltier
  elements. This method will require a current of
  few Amps (up to 3-5A) to get the APD down to
  about 40 degrees Celsius. (doesnt require very
  stable power supply. Can use a spare AT computer
  power supply.)

4
3
above shows the housing of APD and not the actual
box which will the shows later.
7
Peltier Elements

• Low-cost about 35 per each element or less
• Allows good temperature control, as precise as
  0.1 degree at around 20oC,
• Performance and precision somewhat degrade at
  negative temperatures because the element will
  require a large current (? 5A) in that range,
  which is not easy to control.

8
Box design

• The box design of the APD allows up to two
  peltier elements for better control and allowing
  to achieve lower temperatures (theoretically down
  to 30o C or even lower if 4 elements are used
  stacked.
• Usage of 2 elements allows to minimize currents
  for better controllability and stability.

above shows the right and left sides of the box
that are just smooth surfaces.
9
Box Design

• The front side allows two standard optical
  connectors to be used for greater flexibility of
  the design.

10
Box Design

• Bottom and top parts of the box allow the
  connectors and holders and the amplifier box to
  be attached.

11
Box Design
8
6
5

• This is an artistic representation of the box
  that will have APD inside and the box with
  pre-amplifier (which is not being cooled as of
  current scheme but the ability to do this has
  been integrated into this particular design).