Design support

Power supply support

The actual power supply for the CD-PRO2LF playback system consists of 2 sections.

· Power supply for the CD-PRO2LF

· Power supply for the Display section

The XO3 board has an on board power supply and can be run direct from the 9V. More on this subject can be found here at job 7.

Supporting information:

· PDF file with some example power supplies can be found in the section power.
Many the same components supply
Simple negative voltages supply
ATX computer supply
Battery powered supply

· Page with overview of currents and voltages

Power supply for the CD-PRO2LF

The power supply for the CD-PRO2LF consists of a positive 9V supply and a positive 5V supply. Both make use of the same ground and both are rated below 1 Ampere. The 9V supply is mainly used to drive the motors and the actuators in the system. Therefore the required accuracy of the level is not important, the handling of pulses is however important. The 5V supply is mainly used for the operation of the servo and decoder section. Internally on the PCB this voltage is brought once more down to 3.3V for the digital section. The consequence of this 3.3V is however that an external clock should be inserted as well with a maximum of 3.3V and that one can expect only 3.3V levels of the signals coming from IC pins. Cl16 is such a signal as also the signal used by the Tentlabs XO3 board for re-clocking the digital output. Both the 9V and the 5V have an influence on the analogue audio section of the CD-PRO2LF. If you want to use this output direct then it is advised to make a well stabilized and responsive 9V and a well stabilized and responsive 5V section.

Both voltages should be available at nearly the same time when switched on. Therefore they should be loaded with about the same buffering capacitance. Unlike in the past the timing of the power supply is no longer critical.

Power supply for the Display section

The display section makes use of a VFT display in order to have a bright near white display allowing for the use of various colour filters.

The VFTD Vacuum Fluorescent Tube Display is in fact a tube and needs filament heating as well as a negative bias voltage.

Both supplies, the heating and the bias are not critical as they only serve the purpose of getting light on the display. As well a +5V voltage is required for the operation of the processor on the display PCB.

We offered in the past two types of display PCB.

N-version this PCB requires the negative voltages as well as the +5 voltage. ( Today the N version is no longer supplied. )

S-version this PCB only requires a positive +5 voltage and generates on the board it self the other required voltages. (still offered)

In the power supply design considerations the negative voltages are discussed and it is shown how to make them. It should be noted that the negative voltages do not require a good stability and accuracy. Deviations up to 30% are not critical as long as they do not exceed the maximum limitations.

In the S-version we stabilize the bias voltages in a narrow 5 % window. The S version has now become the standard one for shipping.