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PRO-150 Issue History

These notes are by serial number, rather than by date. The list is mainly for 4QD internal reference so is somewhat technical.

0000 to 0105

Are Mark 1. In these, there was no 12v connection to Q21c, R61, C15, C16, R54, D5, R54. Controller (surprisingly) still worked. However removing C1 causes power supply instability. The missing 12v link should be added and C1 removed.

0001 to 0049

These were parallel interface to the display: this was too sensitive to noise

0050 to 0104

Display was changed to a serial input. Controller and software were modified. Circuit board was not changed.

0106 to 0197

Were not used.

0198 to 320 (26 Sept 2007)

These are early Mk 2. Software 2.0 or 2.1 R5 (display clock line) was 10K.
C1 should be removed.


R5 reduced to 1K0 to optimise display driving.
C1 should be removed.


Software 2.2. Display on 2.1 could corrupt. With 2.2, display is refreshed so does not stay corrupted.
C1 should be removed.

0320 to 0498 (16 March 2009)

Relay drivers were changed from BC807 to MMBTA56.
BC807 could fail at higher battery voltages.
C1 should be removed.

0499 to 0549 (14 March 2011)

Issue 6 circuit board. Some value changes to prevent noise problems.
C1 should be removed.

0550 to 0749 (5 September 2011)

Issue 6a. C1 in the power supply removed. It’s not necessary (but see note) and can cause failure of the power supply when used on 48v. See Modification note.

0750 on (3 June 2014)

Issue 6b. Pole transistor replaced with a MOSFET. This improves switching, as well as removing several components from the circuit board.
A resistor was also added in the parking brake circuit. If the parking brake is shorted this can blow the drivers on 48v and it destroys the microcontroller. The extra resistor protects the micro.
R 39 was 3K3. Changed to 22K. Reversing threshold was about 18v. With this change, threshold has been dropped to 4.7v.


From June 2015 the Pro-150 changed to having the serial number on the box label. Software version 2.3 was also introduced at this time, the main changes for 2.3 are;

  1. A power down mode was introduced that shows [pd] when the Pro-150 is delivering zero power. It then switches to a low power standby state, and the display goes blank after around 20 seconds.
  2. The way the “slow / fast” switch works was changed.¬† If this switch [- on the programmer] is held down for 3 seconds at start-up then the controller will switch to personality 9.

We do have version 2.4 available that does not allow the Pro-150 to go into power down mode.


From September 2016 software version 2.5 was introduced. This changed one of the parameters tested during start-up, and was done to improve production yield at 50V.


From April 2017 two changes were made to the internal fuse settings of the microprocessor.

  1. The brown out detection voltage was increased from 2.7V to 4.3V to improve resilience under fluctuating power supply and load spike conditions.
  2. The oscillator type was changed to full swing mode to give increased noise immunity.