Folks:
I'm building an integrated amp with my daughter and don't understand how to design a bipolar voltage divider for the project. I've never built a project with a voltage divider before but generally understand how the circuit works. What I'm unclear on is whether I essentially need two separate voltage dividers or a circuit that combines two voltage dividers to achieve the result my daughter and I want.
Specifically, I'm looking for +/- 17 VDC to power the buffers. The amp's toroid has two pairs of 15 VAC secondaries for this purpose and each pair will connect to its own bridge rectifier. We'll get just over 20 VDC off of the bridge rectifiers (after diode losses) and we need to reduce that by roughly 3 VDC. The voltage dividers (presumably consisting of 1.9k and 10k resistors) will go between those rectifiers and the bipolar capacitor bank that will feed the buffers. What I can't figure out is how to wire the two voltage dividers in relation to each other (I've come up with a few alternatives but have no idea which of them -- if any -- is correct). My search online for a bipolar voltage divider variant wasn't fruitful.
Can someone provide some guidance?
Thank you,
Scott
I'm building an integrated amp with my daughter and don't understand how to design a bipolar voltage divider for the project. I've never built a project with a voltage divider before but generally understand how the circuit works. What I'm unclear on is whether I essentially need two separate voltage dividers or a circuit that combines two voltage dividers to achieve the result my daughter and I want.
Specifically, I'm looking for +/- 17 VDC to power the buffers. The amp's toroid has two pairs of 15 VAC secondaries for this purpose and each pair will connect to its own bridge rectifier. We'll get just over 20 VDC off of the bridge rectifiers (after diode losses) and we need to reduce that by roughly 3 VDC. The voltage dividers (presumably consisting of 1.9k and 10k resistors) will go between those rectifiers and the bipolar capacitor bank that will feed the buffers. What I can't figure out is how to wire the two voltage dividers in relation to each other (I've come up with a few alternatives but have no idea which of them -- if any -- is correct). My search online for a bipolar voltage divider variant wasn't fruitful.
Can someone provide some guidance?
Thank you,
Scott
For power supplies use a voltage regulator, not a divider. Divider's only work for no load, or a constant resistive load (which changes the ratio), neither of which apply to active circuitry...
With bipolar supplies its important to have diodes across the outputs so that the +ve rail can't go below 0V and the -ve rail can't go above 0V. Its nice to have circuitry that will kill the other supply if one fails, but that's quite complicated.
Why 17V? 15V and 18V are standard voltages supported by common regulators like 7815, 7915
With bipolar supplies its important to have diodes across the outputs so that the +ve rail can't go below 0V and the -ve rail can't go above 0V. Its nice to have circuitry that will kill the other supply if one fails, but that's quite complicated.
Why 17V? 15V and 18V are standard voltages supported by common regulators like 7815, 7915
rayma:
That's an interesting idea -- I hadn't thought of that. Thank you (though it's likely I'll go the route Mark suggested)!
Mark:
The buffer is RJM's B-buffer, which apparently is optimized for +/- 17 VDC. Thanks for redirecting me -- it seems I was stumbling in the wrong direction.
Regards,
Scott
That's an interesting idea -- I hadn't thought of that. Thank you (though it's likely I'll go the route Mark suggested)!
Mark:
The buffer is RJM's B-buffer, which apparently is optimized for +/- 17 VDC. Thanks for redirecting me -- it seems I was stumbling in the wrong direction.
Regards,
Scott