The electronic part of the Audine camera requires a +/-15V symmetrical power supply. Consumption is 30 mA for the positive voltage and 10 mA for the negative voltage. If possible, the peak-to-peak ripple must be lower than 5 mV. To reduce the electronic noise level, it is recommended to choose a linear type power supply instead of a switching power supply since the aim is to control sensitive electronic circuits such as the ones in a CCD camera. The required power supply can be easily built using 7815-type voltage regulators (for the positive voltage) and 7915 regulators for the negative voltage as well as a transformer, a few capacitors and rectifier diodes.

It is however easier to buy it from a shop where it will cost you less than $50 (in France). Manufacturing such a device might then be a waste of time in some instances. The AL890N power supply made by the company ELC for instance is adequate. The only problem with a low-end power supply is that it does not tell you how much current is actually used up. That is a pity because this value gives a good indication to trouble-shoot the device (to detect short circuits, wrong connections, etc). Generally, measuring a current using a VU meter or a LED display is only available on more costly power supplies ($150 and more). Note however that for a normal operation of Audine you must not use a laboratory power supply because the output voltage can be adjusted. In such a case, an incorrect setting can overload the camera and seriously damage its components.

Whatever type of power supply you choose, you must be really careful not to reverse the polarity. Before you switch on an electronic equipment, be sure the power supply wires are correctly connected.

This is a high-end regulated double power supply with many settings on the front face. Be careful because these settings can be wrongly adjusted and for your camera's sake you should choose a model with symmetrical fixed voltages.

To supply the Peltier module, you need a 5V DC voltage with at least 2.6A. To generate this voltage, the best is to use a computer power supply. It is a switching power supply but that is acceptable since it is used to supply the Peltier module. It can generate a high current flow under 5V (20A for instance, ie more than is necessary). The price is very low - sometimes less than $16. It must be noted that the Audine cooling device has been designed so that such a cost-efficient power supply can be used. Another big advantage of a PC power supply is that it generates the 12V voltage required by the fan that cools the Peltier module radiator.

Be careful though with the most recent PC power supplies, in particular those compliant with Intel ATX standard. You may have to install wires at a terminal (simple operation) so that it actually delivers a voltage (these power supplies can be electronically cut off). Similarly, the +12V voltage used for the camera fan will not be generated if the power supply is incorrectly wired. For more information about ATX power supplies, click here. The PS/2 (or AT) power supplies are more traditional and do not pose this kind of problems. They must therefore be the preferred choice.

This is the ideal couple to supply the Audine. On the left-hand side, a PC power supply for the Peltier cooling system. On the right-hand side, a +/-15V off-the-shelf power supply for the electronic part (ELC, model AL890N). This will cost $70. If you buy a box in which to put these components and a few connectors and switches, the total cost for the Audine power supply should not be above $110.
Detailed characteristics of a PC power supply. This model generates up to 20A under 5V. This kind of equipment can be found in nearly any computer shop.

To route the Peltier voltage generated by the PC power supply to the camera, you have to make a special cable fitted at one end with a 4-contact male connector, the kind used to supply computer equipment. It is a very usual component that can be found in computer shops. This connector can be taken from a hard disk or CD-ROM extension cable.

Voltage extension cable. It can be found in many computer shops and even department stores. The red wire carries the +5V voltage, the black carries the ground and the yellow wire carries the +12V voltage. Note that the +5V wire and the ground are sometimes doubled due to the high currents they might convey.
Complete power supply cable. The wires from the 4-contact male connector are soldered to strands that carry the current to the DB15 connector which is directly connected to the Audine camera. Remember that the red wires are for the +5V voltage, the black wires for the ground and the yellow wire for the +12V voltage.

You have to complete the DB15 connector wiring. Up to now, the 1, 2, and 3 pins of the DB15 connector were respectively used by the +15V voltage, the ground and the -15V voltage to supply the electronic circuits.

Detailed wiring of the DB15 connector. From right to left, the +15V voltage (red), the electronic ground (green), the -15V voltage (black), the two Peltier positive supply (pink), the two supply wires for the Peltier module ground (blue) and the +12V voltage for the fan supply.

The wiring diagram of the DB15 connector is as follows:

+15V (electronic)
Ground (electronic)
-15V (electronic)
+5V (Peltier)
+5V (Peltier)
Ground (Peltier)
Ground (Peltier)
+12V (fan)

Because the current generated in the Peltier module is rather high, and in order to limit the voltage drop in the power supply wires, the latter have been doubled for the 5V voltage and the Peltier ground. The fan ground is the same as the Peltier module ground. Note that the electronic ground and the Peltier ground are completely separated. To avoid any problems, it is recommended to put all the power supply modules (+/-15V, +5V, +12V) in a single box. An Audine power supply DB15 connector must be installed on the front face of the box so that you do not hesitate when connecting the wires.

Example of the front face of an Audine power supply box. You can also add VU meters to check the currents (electronic and Peltier), temperature measurement, etc.
Example of a prototype box containing both the AL890N power supply and the PC power supply. VU meters are used to check the currents and the CCD temperature. By using this type of box, you can avoid having electrical wires lying around everywhere and the camera can be used more safely because you cannot reverse polarity (you only have to make a cable to go from the camera DB15 connector to an identical connector located on a face of the power supply box).
Schematic for the above-mentioned power supply (design Thierry Maciaszek).
A functional and compact Audine power supply manufactured by Raymond David. It comprises the AL890N module and a PC module but, in both cases, the original boxes were removed so that the assembly is more compact. Note the integrated display for the CCD temperature.