I'm sorry, I should have written linear, I stand corrected. I've worked on enough of the darn things. It used to be everything had a linear regulator and heavy transformer but the power supplies were simple and reliable. The 78xx series regulators and LM317's make it so easy to put together a regulated supply for a project. I was working in TV shops back in the 70's when RCA, if I recall correctly, came out with a TV set that used the flyback transformer as a newfangled power supply for the whole set. The company rep had one of the new "all solid state" sets hooked to a variac transformer which he used to run the voltage up and down. We were all impressed by the fact that the set would show a clear but slightly shrunken picture when the power to the set was turned down to 80 volts AC. I knew then that things were know going to get very interesting in the field of consumer electronics. Most of the sets we were working on had hybrid circuitry using transistors and IC chips for low power and low voltage then tubes for the high voltage horizontal output stage. I remember when a horizontal output tube was under $5.00 and a horizontal output transistor was $25.00 or more. Gasoline was also
30 cents a gallon back then. Gosh darnit! I think I'm getting old. :-)I just had a flashback to the good old Radio Shack 12 volt DC power supplies the company sold for powering up a car or CB radio out of a vehicle. The early units used a TO-3 power transistor and a zener diode as a voltage reference in the circuitry. The latter versions used the LM317 and 78xx series regulators. I get the same power now from a wall wort that feels so light for the power it will supply. Oh yea, some of those Radio Shack power supplies were unregulated. :-)
TDD