[OT] Adding volume control to electronic device
gray_wolf wrote:
Remember the old drive in movie theater speakers with the volume control?=
Those were 70V system. 70V constant power going down the cable, each tap
has a step-down transformer, then an L-pad (not a simple pot but a three
element pad so the transformer always sees an 8 ohm load) and a crappy
speaker. Because they were all parallel loads, if the main cable was shorted
by someone driving away without removing the speaker, it would take all of
them down.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
|