48V Phantom Feed Supply for Microphones
Is it appropriate to connect the grounds from Figures 1 and 2? In figure 2, however, the ground would also be connected to "pin 1" on the XLR connections, which will eventually be connected to chassis/earth.
I guess what I'm asking is if it's safe to directly connect earth to the ground on the voltage doubler supply without any adverse effects.
Is it appropriate to connect the grounds from Figures 1 and 2? In figure 2, however, the ground would also be connected to "pin 1" on the XLR connections, which will eventually be connected to chassis/earth.
I guess what I'm asking is if it's safe to directly connect earth to the ground on the voltage doubler supply without any adverse effects.
Moved to Instruments and Amplifiers - hopefully you are more likely to get a good answer here. (Some of these guys are certainly using phantom powered mics, that's my theory at least.) 
Second question - on Figure 4 on this datasheet, http://www.ti.com/lit/ds/symlink/ina217.pdf, regular diodes to the supply rails are used, whereas on the westhost article, zeners are used. Which is preferable, or should both be used?
Third question - Figure 8 on Elliott Sound Products - Linear Power Supply Design shows a voltage doubler rectifier. If I put 24VAC into this I should get around 65VDC?
As long as you have separate winding on transformer just for phantom power.
I checked link and it's Rod Elloiott's project which means it's 100% fully functional. If you want you can replace voltage doubler only by gretz and capacitor and than optionally some 47-100E resistor and one more capacitor. Transformer voltage should be than some 50VAC and capacitors should be 100V types. And please it is very important to make the whole circuit not just power supply. Phantom powering circuit (fig.2) is essential especially those 2 6K8 resistors. Without it you will burn something.
Cheers, Taj
I checked link and it's Rod Elloiott's project which means it's 100% fully functional. If you want you can replace voltage doubler only by gretz and capacitor and than optionally some 47-100E resistor and one more capacitor. Transformer voltage should be than some 50VAC and capacitors should be 100V types. And please it is very important to make the whole circuit not just power supply. Phantom powering circuit (fig.2) is essential especially those 2 6K8 resistors. Without it you will burn something.
Cheers, Taj
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