Andy Peters
Well-known member
I just fixed a friend's Whirlwind Selector box. This guy is an A/B switcher with a common port, an "A" port and a "B" port. You can route the common to "A," "B" or both. It uses two Vactrols each at the "A" and "B" ports. One is series, one is shunt. Operation is obvious. The slowish turn on/turn off times make for a clickless switch, too.
One of the shunt guys died. Instead of the resistor side being at very hi resistance when the LED is dark, it read about 216 ohms. I'm lazy and haven't turned on the LED to see if the resistance changes when lit up.
So what could cause this kind of failure? The thing is supposed to be able to deal with 100V across the resistor, and the logic that drives the LED is still OK.
-a
One of the shunt guys died. Instead of the resistor side being at very hi resistance when the LED is dark, it read about 216 ohms. I'm lazy and haven't turned on the LED to see if the resistance changes when lit up.
So what could cause this kind of failure? The thing is supposed to be able to deal with 100V across the resistor, and the logic that drives the LED is still OK.
-a