Console TV or stereo kill switch

[VintagePC]

Originally Posted by jeyurkon

Then again, the push button type of switch they used for the light might not be able to handle the higher loads of the TV.

Startup current is really what you'd be worried about.... those tube heaters would draw quite a hefty current until they warm up, and that can be many times more than operating current... So you'd need a switch that's many times the current rating of the set when running.

Since you're dealing with quite a bit of current, you'd want something more solid like a throw switch, especially since micro-switches are more susceptible to contact "bounce". To solve that you'd need a low voltage supply to the switch and a relay of some sort to do the actual switch-on... more parts, more cost etc.

I'd also wonder about the safety of a straight up mains switch like this... a tech servicing the cabinet, forgot to unplug it, but it's off, tilts the cabinet a bit, door falls open and *ZAP*.
Or, as in above, you're running 120V through a commonly-accessed area, more potential for the customer to get zapped if wire frays or becomes exposed etc.

[wa2ise]

if the switch was toggled a few times in rapid succession.

Most of these microswitches have a fair amount of mechanical hysteresis (once a door so equipped by such a switch is opened a fair amount to make the switch turn on, you need to close the door further shut to get the switch to turn off. Idea being that if the door is held at the point when the switch turned on, a small amount of random door movement won't make the switch toggle on and off quickly).

the push button type of switch they used for the light might not be able to handle the higher loads of the TV.

Light bulbs are also tough on switches. A cold light bulb has very low resistance, which makes for high inrush current when switched on.

[Eric H]

The Truetone Console I just got has a Mercury switch attached to the door, when the CRT tilts down into the cabinet the TV turns off.

There is a plug on the chassis for the switch, it looks exactly like an auxiliary 120v socket.

[jeyurkon]

Originally Posted by wa2ise

Most of these microswitches have a fair amount of mechanical hysteresis (once a door so equipped by such a switch is opened a fair amount to make the switch turn on, you need to close the door further shut to get the switch to turn off. Idea being that if the door is held at the point when the switch turned on, a small amount of random door movement won't make the switch toggle on and off quickly).



Light bulbs are also tough on switches. A cold light bulb has very low resistance, which makes for high inrush current when switched on.

I was thinking that the transformer would look partially like an inductive load and when the field collapses it would arc across the switch when it was opened slowly like it does in a simple switch.

The power factor of transformer sets is surprisingly good though.