Early outdoor power supplies

What were power supplies schematics like in the early days?

Power supplies schematics were/are like this: In the very early tube days, only the most left schematics was used where the diode was a rectifying tube. Only a half sine is rectified and charging the storage capacitor, causing quite some hum. The transformer is only loaded on the positive sines, so used very inefficiently.

When were switching power supplies invented?

The design and manufacture of switching power supplies can be traced back at least to the 1950s. At that time, these products were produced in huge quantities, mostly to replace vibrators.

What is the evolution of power supply technology?

The evolution of power supply technology is not just a story of electrical and electronic innovation; it’s a narrative that underpins the broader technological advancements of our time.

Why did manufacturers move power supply from inside to outside?

Manufacturers moved the power supply from inside the product to outside and put the power supply in its own package. This innovation hugely simplified manufacturing and safety requirements because the product used only low voltage DC inside.

Do external power supplies guarantee zero standby power use?

External power supplies greatly reduced the cost of manufacture but they also guaranteed standby power use. Now the on-off switch on the product was downstream of the power supply, which left it continuously energized. The only way to assure zero standby was to pull the plug on the 115VAC side.

How do power supplies work?

Power supplies used vacuum tubes for both the power and control elements. Typically, a voltage regulator (VR) tube, the predecessor to today's zener diodes, was used to produce a stable reference. Control was pretty much limited to the manual twisting of knobs. In those days we did not care too much about dissipation.