From DC to Daylight....

I was looking for past circuits built and found my first buildup and secound and third... it was an power supply (on the left image) an batery tester and an FM transmiter (bellow).

The power supply only worked after I correct the initial circuit that came in a magazine, it was something to do with dropdown voltage for an zener that had the series resistor too low, not giving the output voltage wanted.... these were simple circuits but giving lot of fun and a sense of acoumplisment, they were done by the age of 14/15. The power supply box was also made and was part of a school project for one of the electricity lectures.

The batery tester, red for low, yellow for medium and gren for 13.8v











The FM transmiter bellow, range was around 100m from inside the house and with an small wire as antenna.











Probably will rebuild the power supply, after all it's allready a classic... and the 2N3055 used is more tham 20 years of age!