C
Chris W
- Jan 1, 1970
- 0
Suppose you have a 12V supply and need to power a 5V device. If that
device is a simple resistive load like say an incandescent light bulb,
you can simply use the right size resistor to drop the voltage. If the
device is more complex and does not draw a constant current, the
resistor obviously won't work. Something like a 7805 would be the
easiest solution. In both cases you are wasting a lot of power. If the
first case over half the power is just generating heat in the resistor.
I assume the same, or close to the same, amount of power is lost in
the 7805 regulator.
If you needed to light two 5V light bulbs then you could hook them in
series and waste a lot less power by using a smaller resistor.
Now for my question, can you do something similar by using 2 7805
regulators hooked up in series to power 2 separate loads? Alternatively
and more what I want, can you also have the outputs hooked up in
parallel to power one 5V device?
--
Chris W
KE5GIX
"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"
Ham Radio Repeater Database.
http://hrrdb.com
device is a simple resistive load like say an incandescent light bulb,
you can simply use the right size resistor to drop the voltage. If the
device is more complex and does not draw a constant current, the
resistor obviously won't work. Something like a 7805 would be the
easiest solution. In both cases you are wasting a lot of power. If the
first case over half the power is just generating heat in the resistor.
I assume the same, or close to the same, amount of power is lost in
the 7805 regulator.
If you needed to light two 5V light bulbs then you could hook them in
series and waste a lot less power by using a smaller resistor.
Now for my question, can you do something similar by using 2 7805
regulators hooked up in series to power 2 separate loads? Alternatively
and more what I want, can you also have the outputs hooked up in
parallel to power one 5V device?
--
Chris W
KE5GIX
"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"
Ham Radio Repeater Database.
http://hrrdb.com