What's a good way to find power transformers whose no-load dissipation is small enough to meet the sub-1-watt "vampire power" requirements of Energy Star / IEC 62301?
I haven't found any comparison-shopping websites which list this information, nor DigiKey / Mouser / etc. And my vendor of choice, Block Transformers, seems to say the best transformer they can sell me, dissipates 0.9 watts in the transformer alone! Leaving not much at all for the wakey-uppie electronics the transformer supplies.
I've got a small 3VA transformer whose primary is permanently connected to the AC mains whether the power switch is on or off. It powers a teeny splash of stuff that uses a few milliwatts listening to the remote control, waiting for someone to press the PowerOn button, etc. I want to meet Energy Star / IEC 62301 requirements for teeny tiny "vampire power" levels, but it seems the power transformer is getting in my way.
What's the standard solution? What does Cambridge Audio do? What does NAD do?
If you're wondering, why 3VA? the answer is: because when the equipment finally is turned on, and we're no longer aiming for sub-1-watt, this transformer supplies 1.5 watts to the coils of the 15 ampere relays associated with mains-power-enable, soft-start, and other such items.
I haven't found any comparison-shopping websites which list this information, nor DigiKey / Mouser / etc. And my vendor of choice, Block Transformers, seems to say the best transformer they can sell me, dissipates 0.9 watts in the transformer alone! Leaving not much at all for the wakey-uppie electronics the transformer supplies.
I've got a small 3VA transformer whose primary is permanently connected to the AC mains whether the power switch is on or off. It powers a teeny splash of stuff that uses a few milliwatts listening to the remote control, waiting for someone to press the PowerOn button, etc. I want to meet Energy Star / IEC 62301 requirements for teeny tiny "vampire power" levels, but it seems the power transformer is getting in my way.
What's the standard solution? What does Cambridge Audio do? What does NAD do?
If you're wondering, why 3VA? the answer is: because when the equipment finally is turned on, and we're no longer aiming for sub-1-watt, this transformer supplies 1.5 watts to the coils of the 15 ampere relays associated with mains-power-enable, soft-start, and other such items.