Recently I acquired a DC PSU with a RS High Power Voltage Regulator RS
stock nr 30-541-2. Embossed is the code : D7140
The device integrated on a substantial heat sink is probably 20 + yrs old
.. It was made in the UK
I can't find any reference in any RS catalogue or on their web site.
The device has 5 pins :
pin 1 + DC input
pin2 - DC input

pin3 and 4 are wire-connected

pin3,4 + output
pin 5 - output

A varying input voltage gives a lower varying output voltage .

The associated transformer (also a RS component) has the following
(centre-tapped ) secondary 13.5 - 0 - 13,5 V @ 3A with bridge rectifier
and the 4 electrolytic capacitors (all in parallel) are having a working
voltage of 25 V , so it highly likely was a 20to24 V-DC PSU Any spec.
info regarding the heat-sinked device will be much appreciated.

Frank GM0CSZ / KN6WH