Correct volts out on HP-45 PSU

[Steve Simpkin]

The center pin is a common ground to the left and right outside pins.
Center pin to left pin is used to charge the NiCad batteries and will be around 12-16V unloaded.
Center pin to right pin is used to power the calculator circuitry and should be around 3.6-4.7V.

See the following Museum link for more information on the voltages on the plug:
https://www.hpmuseum.org/batts/battery.htm

See the following Museum link for more information on power supply circuitry:
https://www.hpmuseum.org/cgi-sys/cgiwrap...i?read=390