Recognition : Al Akers ZS2U, Andre Botes ZS2ACP and Bryan Haefele ZS2BH (SK)
An article by Al Akers ZS2U describing a power supply appeared in the June 1993 issue of Radio ZS. The circuit, to which a fourth 2N3055 has been added to enhance the current handling capability.
In addition to this ZS2CP has produced a circuit board which incorporates an over voltage protection circuit adapted from n article by the late Brian Haefele ZS2BH in QSX Newsletter of April 2000.
The original article, schematic diagram, PCB outlay and component outlay can be downloaded by clicking HERE.
I constructed this power supply in early 2001 and it has run flawlessly for the past 20 years. This power supply is now connected to the GRHub 145.550 Mhz RF Link Radio and also powers 2 x Fan Controllers discussed on this Blog.
I opened the power supply this past Friday to clean the inside and to fit a auto fan controller to run the fan. (Not shown in the images.) I have tested the fan controller installed to the power supply. It works great and even reduced some of the fan noise considerably.
With both the radio and power supply now fitted with a automatic fan controller, it is really an "assurance of mind" that I do not have to manually switch fans on and off. As the temperature rise it switches on automatically and once the temperature falls below a set level it switches off automatically. Fingers crossed that the fan controllers do not fail which could destroy the radio or the power supply if they overheat. I however do have a plan in mind to inform me should they fail.
Here is a few diagram images of the power supply. Images of the fan controller is also available on this Blog. Just click on Fan Controller in the Labels column.
Click on images for larger view.
