AudioCircle

Other Stuff => Archived Manufacturer Circles => Aspen Amplifiers => Topic started by: Martin on 4 Sep 2004, 12:02 am

Title: Switch for TLP
Post by: Martin on 4 Sep 2004, 12:02 am

I'm re-casing my TLP and want to add a lit rocker power switch (already purchased), but it requires a seperate 3volt load which attach to + & - terminals on the back of the switch. Where is the easiest place to get that 3volt load from.
 I think it can be wired for always lit or only lit when the power is on.
No specs came with the switch.
Any ideas are appreciated.

Thanks
Martin

Title: Switch for TLP
Post by: AKSA on 4 Sep 2004, 12:27 am

Martin,

The current needed by rocker switch lamps could be as high as 50mA at 3V.  It is conceivable you could extract it from the filament winding via a single diode, black band (cathode) to the lamp, with the other terminal of the lamp returning to the other filament winding.

But you will need a resistor, of around 68R 1W, after the diode to drop the voltage from the 6.3Vac down to a suitable DC level.  No smoothing cap is required, as this is an incandescent lamp of high thermal inertia and pulsing won't be evident.

This sort of current is not obtainable from the HT circuits, unfortunately.

Cheers,

Hugh